Fix exception causes all over the codebase

IPython/core/display.py

@@ -1,1206 +1,1206 b''
 # -*- coding: utf-8 -*-
 """Top-level display functions for displaying object in different formats."""
 
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
 
 from binascii import b2a_base64, hexlify
 import json
 import mimetypes
 import os
 import struct
 import warnings
 from copy import deepcopy
 from os.path import splitext
 from pathlib import Path, PurePath
 
 from IPython.utils.py3compat import cast_unicode
 from IPython.testing.skipdoctest import skip_doctest
 from . import display_functions
 
 
 __all__ = ['display_pretty', 'display_html', 'display_markdown',
            'display_svg', 'display_png', 'display_jpeg', 'display_latex', 'display_json',
            'display_javascript', 'display_pdf', 'DisplayObject', 'TextDisplayObject',
            'Pretty', 'HTML', 'Markdown', 'Math', 'Latex', 'SVG', 'ProgressBar', 'JSON',
            'GeoJSON', 'Javascript', 'Image', 'set_matplotlib_formats',
            'set_matplotlib_close',
            'Video']
 
 _deprecated_names = ["display", "clear_output", "publish_display_data", "update_display", "DisplayHandle"]
 
 __all__ = __all__ + _deprecated_names
 
 
 # ----- warn to import from IPython.display -----
 
 from warnings import warn
 
 
 def __getattr__(name):
     if name in _deprecated_names:
         warn(f"Importing {name} from IPython.core.display is deprecated since IPython 7.14, please import from IPython display", DeprecationWarning, stacklevel=2)
         return getattr(display_functions, name)
 
     if name in globals().keys():
         return globals()[name]
     else:
         raise AttributeError(f"module {__name__} has no attribute {name}")
 
 
 #-----------------------------------------------------------------------------
 # utility functions
 #-----------------------------------------------------------------------------
 
 def _safe_exists(path):
     """Check path, but don't let exceptions raise"""
     try:
         return os.path.exists(path)
     except Exception:
         return False
 
 
 def _display_mimetype(mimetype, objs, raw=False, metadata=None):
     """internal implementation of all display_foo methods
 
     Parameters
     ----------
     mimetype : str
         The mimetype to be published (e.g. 'image/png')
     *objs : object
         The Python objects to display, or if raw=True raw text data to
         display.
     raw : bool
         Are the data objects raw data or Python objects that need to be
         formatted before display? [default: False]
     metadata : dict (optional)
         Metadata to be associated with the specific mimetype output.
     """
     if metadata:
         metadata = {mimetype: metadata}
     if raw:
         # turn list of pngdata into list of { 'image/png': pngdata }
         objs = [ {mimetype: obj} for obj in objs ]
     display(*objs, raw=raw, metadata=metadata, include=[mimetype])
 
 #-----------------------------------------------------------------------------
 # Main functions
 #-----------------------------------------------------------------------------
 
 
 def display_pretty(*objs, **kwargs):
     """Display the pretty (default) representation of an object.
 
     Parameters
     ----------
     *objs : object
         The Python objects to display, or if raw=True raw text data to
         display.
     raw : bool
         Are the data objects raw data or Python objects that need to be
         formatted before display? [default: False]
     metadata : dict (optional)
         Metadata to be associated with the specific mimetype output.
     """
     _display_mimetype('text/plain', objs, **kwargs)
 
 
 def display_html(*objs, **kwargs):
     """Display the HTML representation of an object.
 
     Note: If raw=False and the object does not have a HTML
     representation, no HTML will be shown.
 
     Parameters
     ----------
     *objs : object
         The Python objects to display, or if raw=True raw HTML data to
         display.
     raw : bool
         Are the data objects raw data or Python objects that need to be
         formatted before display? [default: False]
     metadata : dict (optional)
         Metadata to be associated with the specific mimetype output.
     """
     _display_mimetype('text/html', objs, **kwargs)
 
 
 def display_markdown(*objs, **kwargs):
     """Displays the Markdown representation of an object.
 
     Parameters
     ----------
     *objs : object
         The Python objects to display, or if raw=True raw markdown data to
         display.
     raw : bool
         Are the data objects raw data or Python objects that need to be
         formatted before display? [default: False]
     metadata : dict (optional)
         Metadata to be associated with the specific mimetype output.
     """
 
     _display_mimetype('text/markdown', objs, **kwargs)
 
 
 def display_svg(*objs, **kwargs):
     """Display the SVG representation of an object.
 
     Parameters
     ----------
     *objs : object
         The Python objects to display, or if raw=True raw svg data to
         display.
     raw : bool
         Are the data objects raw data or Python objects that need to be
         formatted before display? [default: False]
     metadata : dict (optional)
         Metadata to be associated with the specific mimetype output.
     """
     _display_mimetype('image/svg+xml', objs, **kwargs)
 
 
 def display_png(*objs, **kwargs):
     """Display the PNG representation of an object.
 
     Parameters
     ----------
     *objs : object
         The Python objects to display, or if raw=True raw png data to
         display.
     raw : bool
         Are the data objects raw data or Python objects that need to be
         formatted before display? [default: False]
     metadata : dict (optional)
         Metadata to be associated with the specific mimetype output.
     """
     _display_mimetype('image/png', objs, **kwargs)
 
 
 def display_jpeg(*objs, **kwargs):
     """Display the JPEG representation of an object.
 
     Parameters
     ----------
     *objs : object
         The Python objects to display, or if raw=True raw JPEG data to
         display.
     raw : bool
         Are the data objects raw data or Python objects that need to be
         formatted before display? [default: False]
     metadata : dict (optional)
         Metadata to be associated with the specific mimetype output.
     """
     _display_mimetype('image/jpeg', objs, **kwargs)
 
 
 def display_latex(*objs, **kwargs):
     """Display the LaTeX representation of an object.
 
     Parameters
     ----------
     *objs : object
         The Python objects to display, or if raw=True raw latex data to
         display.
     raw : bool
         Are the data objects raw data or Python objects that need to be
         formatted before display? [default: False]
     metadata : dict (optional)
         Metadata to be associated with the specific mimetype output.
     """
     _display_mimetype('text/latex', objs, **kwargs)
 
 
 def display_json(*objs, **kwargs):
     """Display the JSON representation of an object.
 
     Note that not many frontends support displaying JSON.
 
     Parameters
     ----------
     *objs : object
         The Python objects to display, or if raw=True raw json data to
         display.
     raw : bool
         Are the data objects raw data or Python objects that need to be
         formatted before display? [default: False]
     metadata : dict (optional)
         Metadata to be associated with the specific mimetype output.
     """
     _display_mimetype('application/json', objs, **kwargs)
 
 
 def display_javascript(*objs, **kwargs):
     """Display the Javascript representation of an object.
 
     Parameters
     ----------
     *objs : object
         The Python objects to display, or if raw=True raw javascript data to
         display.
     raw : bool
         Are the data objects raw data or Python objects that need to be
         formatted before display? [default: False]
     metadata : dict (optional)
         Metadata to be associated with the specific mimetype output.
     """
     _display_mimetype('application/javascript', objs, **kwargs)
 
 
 def display_pdf(*objs, **kwargs):
     """Display the PDF representation of an object.
 
     Parameters
     ----------
     *objs : object
         The Python objects to display, or if raw=True raw javascript data to
         display.
     raw : bool
         Are the data objects raw data or Python objects that need to be
         formatted before display? [default: False]
     metadata : dict (optional)
         Metadata to be associated with the specific mimetype output.
     """
     _display_mimetype('application/pdf', objs, **kwargs)
 
 
 #-----------------------------------------------------------------------------
 # Smart classes
 #-----------------------------------------------------------------------------
 
 
 class DisplayObject(object):
     """An object that wraps data to be displayed."""
 
     _read_flags = 'r'
     _show_mem_addr = False
     metadata = None
 
     def __init__(self, data=None, url=None, filename=None, metadata=None):
         """Create a display object given raw data.
 
         When this object is returned by an expression or passed to the
         display function, it will result in the data being displayed
         in the frontend. The MIME type of the data should match the
         subclasses used, so the Png subclass should be used for 'image/png'
         data. If the data is a URL, the data will first be downloaded
         and then displayed. If
 
         Parameters
         ----------
         data : unicode, str or bytes
             The raw data or a URL or file to load the data from
         url : unicode
             A URL to download the data from.
         filename : unicode
             Path to a local file to load the data from.
         metadata : dict
             Dict of metadata associated to be the object when displayed
         """
         if isinstance(data, (Path, PurePath)):
             data = str(data)
 
         if data is not None and isinstance(data, str):
             if data.startswith('http') and url is None:
                 url = data
                 filename = None
                 data = None
             elif _safe_exists(data) and filename is None:
                 url = None
                 filename = data
                 data = None
 
         self.url = url
         self.filename = filename
         # because of @data.setter methods in
         # subclasses ensure url and filename are set
         # before assigning to self.data
         self.data = data
 
         if metadata is not None:
             self.metadata = metadata
         elif self.metadata is None:
             self.metadata = {}
 
         self.reload()
         self._check_data()
 
     def __repr__(self):
         if not self._show_mem_addr:
             cls = self.__class__
             r = "<%s.%s object>" % (cls.__module__, cls.__name__)
         else:
             r = super(DisplayObject, self).__repr__()
         return r
 
     def _check_data(self):
         """Override in subclasses if there's something to check."""
         pass
 
     def _data_and_metadata(self):
         """shortcut for returning metadata with shape information, if defined"""
         if self.metadata:
             return self.data, deepcopy(self.metadata)
         else:
             return self.data
 
     def reload(self):
         """Reload the raw data from file or URL."""
         if self.filename is not None:
             with open(self.filename, self._read_flags) as f:
                 self.data = f.read()
         elif self.url is not None:
             # Deferred import
             from urllib.request import urlopen
             response = urlopen(self.url)
             data = response.read()
             # extract encoding from header, if there is one:
             encoding = None
             if 'content-type' in response.headers:
                 for sub in response.headers['content-type'].split(';'):
                     sub = sub.strip()
                     if sub.startswith('charset'):
                         encoding = sub.split('=')[-1].strip()
                         break
             if 'content-encoding' in response.headers:
                 # TODO: do deflate?
                 if 'gzip' in response.headers['content-encoding']:
                     import gzip
                     from io import BytesIO
                     with gzip.open(BytesIO(data), 'rt', encoding=encoding) as fp:
                         encoding = None
                         data = fp.read()
                     
             # decode data, if an encoding was specified
             # We only touch self.data once since
             # subclasses such as SVG have @data.setter methods
             # that transform self.data into ... well svg.
             if encoding:
                 self.data = data.decode(encoding, 'replace')
             else:
                 self.data = data
 
 
 class TextDisplayObject(DisplayObject):
     """Validate that display data is text"""
     def _check_data(self):
         if self.data is not None and not isinstance(self.data, str):
             raise TypeError("%s expects text, not %r" % (self.__class__.__name__, self.data))
 
 class Pretty(TextDisplayObject):
 
     def _repr_pretty_(self, pp, cycle):
         return pp.text(self.data)
 
 
 class HTML(TextDisplayObject):
 
     def __init__(self, data=None, url=None, filename=None, metadata=None):
         def warn():
             if not data:
                 return False
 
             #
             # Avoid calling lower() on the entire data, because it could be a
             # long string and we're only interested in its beginning and end.
             #
             prefix = data[:10].lower()
             suffix = data[-10:].lower()
             return prefix.startswith("<iframe ") and suffix.endswith("</iframe>")
 
         if warn():
             warnings.warn("Consider using IPython.display.IFrame instead")
         super(HTML, self).__init__(data=data, url=url, filename=filename, metadata=metadata)
 
     def _repr_html_(self):
         return self._data_and_metadata()
 
     def __html__(self):
         """
         This method exists to inform other HTML-using modules (e.g. Markupsafe,
         htmltag, etc) that this object is HTML and does not need things like
         special characters (<>&) escaped.
         """
         return self._repr_html_()
 
 
 class Markdown(TextDisplayObject):
 
     def _repr_markdown_(self):
         return self._data_and_metadata()
 
 
 class Math(TextDisplayObject):
 
     def _repr_latex_(self):
         s = r"$\displaystyle %s$" % self.data.strip('$')
         if self.metadata:
             return s, deepcopy(self.metadata)
         else:
             return s
 
 
 class Latex(TextDisplayObject):
 
     def _repr_latex_(self):
         return self._data_and_metadata()
 
 
 class SVG(DisplayObject):
     """Embed an SVG into the display.
 
     Note if you just want to view a svg image via a URL use `:class:Image` with
     a url=URL keyword argument.
     """
 
     _read_flags = 'rb'
     # wrap data in a property, which extracts the <svg> tag, discarding
     # document headers
     _data = None
 
     @property
     def data(self):
         return self._data
 
     @data.setter
     def data(self, svg):
         if svg is None:
             self._data = None
             return
         # parse into dom object
         from xml.dom import minidom
         x = minidom.parseString(svg)
         # get svg tag (should be 1)
         found_svg = x.getElementsByTagName('svg')
         if found_svg:
             svg = found_svg[0].toxml()
         else:
             # fallback on the input, trust the user
             # but this is probably an error.
             pass
         svg = cast_unicode(svg)
         self._data = svg
 
     def _repr_svg_(self):
         return self._data_and_metadata()
 
 class ProgressBar(DisplayObject):
     """Progressbar supports displaying a progressbar like element
     """
     def __init__(self, total):
         """Creates a new progressbar
 
         Parameters
         ----------
         total : int
             maximum size of the progressbar
         """
         self.total = total
         self._progress = 0
         self.html_width = '60ex'
         self.text_width = 60
         self._display_id = hexlify(os.urandom(8)).decode('ascii')
 
     def __repr__(self):
         fraction = self.progress / self.total
         filled = '=' * int(fraction * self.text_width)
         rest = ' ' * (self.text_width - len(filled))
         return '[{}{}] {}/{}'.format(
             filled, rest,
             self.progress, self.total,
         )
 
     def _repr_html_(self):
         return "<progress style='width:{}' max='{}' value='{}'></progress>".format(
             self.html_width, self.total, self.progress)
 
     def display(self):
         display(self, display_id=self._display_id)
 
     def update(self):
         display(self, display_id=self._display_id, update=True)
 
     @property
     def progress(self):
         return self._progress
 
     @progress.setter
     def progress(self, value):
         self._progress = value
         self.update()
 
     def __iter__(self):
         self.display()
         self._progress = -1 # First iteration is 0
         return self
 
     def __next__(self):
         """Returns current value and increments display by one."""
         self.progress += 1
         if self.progress < self.total:
             return self.progress
         else:
             raise StopIteration()
 
 class JSON(DisplayObject):
     """JSON expects a JSON-able dict or list
 
     not an already-serialized JSON string.
 
     Scalar types (None, number, string) are not allowed, only dict or list containers.
     """
     # wrap data in a property, which warns about passing already-serialized JSON
     _data = None
     def __init__(self, data=None, url=None, filename=None, expanded=False, metadata=None, root='root', **kwargs):
         """Create a JSON display object given raw data.
 
         Parameters
         ----------
         data : dict or list
             JSON data to display. Not an already-serialized JSON string.
             Scalar types (None, number, string) are not allowed, only dict
             or list containers.
         url : unicode
             A URL to download the data from.
         filename : unicode
             Path to a local file to load the data from.
         expanded : boolean
             Metadata to control whether a JSON display component is expanded.
         metadata: dict
             Specify extra metadata to attach to the json display object.
         root : str
             The name of the root element of the JSON tree
         """
         self.metadata = {
             'expanded': expanded,
             'root': root,
         }
         if metadata:
             self.metadata.update(metadata)
         if kwargs:
             self.metadata.update(kwargs)
         super(JSON, self).__init__(data=data, url=url, filename=filename)
 
     def _check_data(self):
         if self.data is not None and not isinstance(self.data, (dict, list)):
             raise TypeError("%s expects JSONable dict or list, not %r" % (self.__class__.__name__, self.data))
 
     @property
     def data(self):
         return self._data
 
     @data.setter
     def data(self, data):
         if isinstance(data, (Path, PurePath)):
             data = str(data)
 
         if isinstance(data, str):
             if self.filename is None and self.url is None:
                 warnings.warn("JSON expects JSONable dict or list, not JSON strings")
             data = json.loads(data)
         self._data = data
 
     def _data_and_metadata(self):
         return self.data, self.metadata
 
     def _repr_json_(self):
         return self._data_and_metadata()
 
 _css_t = """var link = document.createElement("link");
 	link.ref = "stylesheet";
 	link.type = "text/css";
 	link.href = "%s";
 	document.head.appendChild(link);
 """
 
 _lib_t1 = """new Promise(function(resolve, reject) {
 	var script = document.createElement("script");
 	script.onload = resolve;
 	script.onerror = reject;
 	script.src = "%s";
 	document.head.appendChild(script);
 }).then(() => {
 """
 
 _lib_t2 = """
 });"""
 
 class GeoJSON(JSON):
     """GeoJSON expects JSON-able dict
 
     not an already-serialized JSON string.
 
     Scalar types (None, number, string) are not allowed, only dict containers.
     """
 
     def __init__(self, *args, **kwargs):
         """Create a GeoJSON display object given raw data.
 
         Parameters
         ----------
         data : dict or list
             VegaLite data. Not an already-serialized JSON string.
             Scalar types (None, number, string) are not allowed, only dict
             or list containers.
         url_template : string
             Leaflet TileLayer URL template: http://leafletjs.com/reference.html#url-template
         layer_options : dict
             Leaflet TileLayer options: http://leafletjs.com/reference.html#tilelayer-options
         url : unicode
             A URL to download the data from.
         filename : unicode
             Path to a local file to load the data from.
         metadata: dict
             Specify extra metadata to attach to the json display object.
 
         Examples
         --------
 
         The following will display an interactive map of Mars with a point of
         interest on frontend that do support GeoJSON display.
 
             >>> from IPython.display import GeoJSON
 
             >>> GeoJSON(data={
             ...     "type": "Feature",
             ...     "geometry": {
             ...         "type": "Point",
             ...         "coordinates": [-81.327, 296.038]
             ...     }
             ... },
             ... url_template="http://s3-eu-west-1.amazonaws.com/whereonmars.cartodb.net/{basemap_id}/{z}/{x}/{y}.png",
             ... layer_options={
             ...     "basemap_id": "celestia_mars-shaded-16k_global",
             ...     "attribution" : "Celestia/praesepe",
             ...     "minZoom" : 0,
             ...     "maxZoom" : 18,
             ... })
             <IPython.core.display.GeoJSON object>
 
         In the terminal IPython, you will only see the text representation of
         the GeoJSON object.
 
         """
 
         super(GeoJSON, self).__init__(*args, **kwargs)
 
 
     def _ipython_display_(self):
         bundle = {
             'application/geo+json': self.data,
             'text/plain': '<IPython.display.GeoJSON object>'
         }
         metadata = {
             'application/geo+json': self.metadata
         }
         display(bundle, metadata=metadata, raw=True)
 
 class Javascript(TextDisplayObject):
 
     def __init__(self, data=None, url=None, filename=None, lib=None, css=None):
         """Create a Javascript display object given raw data.
 
         When this object is returned by an expression or passed to the
         display function, it will result in the data being displayed
         in the frontend. If the data is a URL, the data will first be
         downloaded and then displayed.
 
         In the Notebook, the containing element will be available as `element`,
         and jQuery will be available.  Content appended to `element` will be
         visible in the output area.
 
         Parameters
         ----------
         data : unicode, str or bytes
             The Javascript source code or a URL to download it from.
         url : unicode
             A URL to download the data from.
         filename : unicode
             Path to a local file to load the data from.
         lib : list or str
             A sequence of Javascript library URLs to load asynchronously before
             running the source code. The full URLs of the libraries should
             be given. A single Javascript library URL can also be given as a
             string.
         css: : list or str
             A sequence of css files to load before running the source code.
             The full URLs of the css files should be given. A single css URL
             can also be given as a string.
         """
         if isinstance(lib, str):
             lib = [lib]
         elif lib is None:
             lib = []
         if isinstance(css, str):
             css = [css]
         elif css is None:
             css = []
         if not isinstance(lib, (list,tuple)):
             raise TypeError('expected sequence, got: %r' % lib)
         if not isinstance(css, (list,tuple)):
             raise TypeError('expected sequence, got: %r' % css)
         self.lib = lib
         self.css = css
         super(Javascript, self).__init__(data=data, url=url, filename=filename)
 
     def _repr_javascript_(self):
         r = ''
         for c in self.css:
             r += _css_t % c
         for l in self.lib:
             r += _lib_t1 % l
         r += self.data
         r += _lib_t2*len(self.lib)
         return r
 
 # constants for identifying png/jpeg data
 _PNG = b'\x89PNG\r\n\x1a\n'
 _JPEG = b'\xff\xd8'
 
 def _pngxy(data):
     """read the (width, height) from a PNG header"""
     ihdr = data.index(b'IHDR')
     # next 8 bytes are width/height
     return struct.unpack('>ii', data[ihdr+4:ihdr+12])
 
 def _jpegxy(data):
     """read the (width, height) from a JPEG header"""
     # adapted from http://www.64lines.com/jpeg-width-height
 
     idx = 4
     while True:
         block_size = struct.unpack('>H', data[idx:idx+2])[0]
         idx = idx + block_size
         if data[idx:idx+2] == b'\xFF\xC0':
             # found Start of Frame
             iSOF = idx
             break
         else:
             # read another block
             idx += 2
 
     h, w = struct.unpack('>HH', data[iSOF+5:iSOF+9])
     return w, h
 
 def _gifxy(data):
     """read the (width, height) from a GIF header"""
     return struct.unpack('<HH', data[6:10])
 
 
 class Image(DisplayObject):
 
     _read_flags = 'rb'
     _FMT_JPEG = u'jpeg'
     _FMT_PNG = u'png'
     _FMT_GIF = u'gif'
     _ACCEPTABLE_EMBEDDINGS = [_FMT_JPEG, _FMT_PNG, _FMT_GIF]
     _MIMETYPES = {
         _FMT_PNG: 'image/png',
         _FMT_JPEG: 'image/jpeg',
         _FMT_GIF: 'image/gif',
     }
 
     def __init__(self, data=None, url=None, filename=None, format=None,
                  embed=None, width=None, height=None, retina=False,
                  unconfined=False, metadata=None):
         """Create a PNG/JPEG/GIF image object given raw data.
 
         When this object is returned by an input cell or passed to the
         display function, it will result in the image being displayed
         in the frontend.
 
         Parameters
         ----------
         data : unicode, str or bytes
             The raw image data or a URL or filename to load the data from.
             This always results in embedded image data.
         url : unicode
             A URL to download the data from. If you specify `url=`,
             the image data will not be embedded unless you also specify `embed=True`.
         filename : unicode
             Path to a local file to load the data from.
             Images from a file are always embedded.
         format : unicode
             The format of the image data (png/jpeg/jpg/gif). If a filename or URL is given
             for format will be inferred from the filename extension.
         embed : bool
             Should the image data be embedded using a data URI (True) or be
             loaded using an <img> tag. Set this to True if you want the image
             to be viewable later with no internet connection in the notebook.
 
             Default is `True`, unless the keyword argument `url` is set, then
             default value is `False`.
 
             Note that QtConsole is not able to display images if `embed` is set to `False`
         width : int
             Width in pixels to which to constrain the image in html
         height : int
             Height in pixels to which to constrain the image in html
         retina : bool
             Automatically set the width and height to half of the measured
             width and height.
             This only works for embedded images because it reads the width/height
             from image data.
             For non-embedded images, you can just set the desired display width
             and height directly.
         unconfined: bool
             Set unconfined=True to disable max-width confinement of the image.
         metadata: dict
             Specify extra metadata to attach to the image.
 
         Examples
         --------
         # embedded image data, works in qtconsole and notebook
         # when passed positionally, the first arg can be any of raw image data,
         # a URL, or a filename from which to load image data.
         # The result is always embedding image data for inline images.
         Image('http://www.google.fr/images/srpr/logo3w.png')
         Image('/path/to/image.jpg')
         Image(b'RAW_PNG_DATA...')
 
         # Specifying Image(url=...) does not embed the image data,
         # it only generates `<img>` tag with a link to the source.
         # This will not work in the qtconsole or offline.
         Image(url='http://www.google.fr/images/srpr/logo3w.png')
 
         """
         if isinstance(data, (Path, PurePath)):
             data = str(data)
 
         if filename is not None:
             ext = self._find_ext(filename)
         elif url is not None:
             ext = self._find_ext(url)
         elif data is None:
             raise ValueError("No image data found. Expecting filename, url, or data.")
         elif isinstance(data, str) and (
             data.startswith('http') or _safe_exists(data)
         ):
             ext = self._find_ext(data)
         else:
             ext = None
 
         if format is None:
             if ext is not None:
                 if ext == u'jpg' or ext == u'jpeg':
                     format = self._FMT_JPEG
                 elif ext == u'png':
                     format = self._FMT_PNG
                 elif ext == u'gif':
                     format = self._FMT_GIF
                 else:
                     format = ext.lower()
             elif isinstance(data, bytes):
                 # infer image type from image data header,
                 # only if format has not been specified.
                 if data[:2] == _JPEG:
                     format = self._FMT_JPEG
 
         # failed to detect format, default png
         if format is None:
             format = self._FMT_PNG
 
         if format.lower() == 'jpg':
             # jpg->jpeg
             format = self._FMT_JPEG
 
         self.format = format.lower()
         self.embed = embed if embed is not None else (url is None)
 
         if self.embed and self.format not in self._ACCEPTABLE_EMBEDDINGS:
             raise ValueError("Cannot embed the '%s' image format" % (self.format))
         if self.embed:
             self._mimetype = self._MIMETYPES.get(self.format)
 
         self.width = width
         self.height = height
         self.retina = retina
         self.unconfined = unconfined
         super(Image, self).__init__(data=data, url=url, filename=filename,
                 metadata=metadata)
 
         if self.width is None and self.metadata.get('width', {}):
             self.width = metadata['width']
 
         if self.height is None and self.metadata.get('height', {}):
             self.height = metadata['height']
 
         if retina:
             self._retina_shape()
 
 
     def _retina_shape(self):
         """load pixel-doubled width and height from image data"""
         if not self.embed:
             return
         if self.format == self._FMT_PNG:
             w, h = _pngxy(self.data)
         elif self.format == self._FMT_JPEG:
             w, h = _jpegxy(self.data)
         elif self.format == self._FMT_GIF:
             w, h = _gifxy(self.data)
         else:
             # retina only supports png
             return
         self.width = w // 2
         self.height = h // 2
 
     def reload(self):
         """Reload the raw data from file or URL."""
         if self.embed:
             super(Image,self).reload()
             if self.retina:
                 self._retina_shape()
 
     def _repr_html_(self):
         if not self.embed:
             width = height = klass = ''
             if self.width:
                 width = ' width="%d"' % self.width
             if self.height:
                 height = ' height="%d"' % self.height
             if self.unconfined:
                 klass = ' class="unconfined"'
             return u'<img src="{url}"{width}{height}{klass}/>'.format(
                 url=self.url,
                 width=width,
                 height=height,
                 klass=klass,
             )
 
     def _repr_mimebundle_(self, include=None, exclude=None):
         """Return the image as a mimebundle
 
         Any new mimetype support should be implemented here.
         """
         if self.embed:
             mimetype = self._mimetype
             data, metadata = self._data_and_metadata(always_both=True)
             if metadata:
                 metadata = {mimetype: metadata}
             return {mimetype: data}, metadata
         else:
             return {'text/html': self._repr_html_()}
 
     def _data_and_metadata(self, always_both=False):
         """shortcut for returning metadata with shape information, if defined"""
         try:
             b64_data = b2a_base64(self.data).decode('ascii')
-        except TypeError:
+        except TypeError as e:
             raise FileNotFoundError(
-                "No such file or directory: '%s'" % (self.data))
+                "No such file or directory: '%s'" % (self.data)) from e
         md = {}
         if self.metadata:
             md.update(self.metadata)
         if self.width:
             md['width'] = self.width
         if self.height:
             md['height'] = self.height
         if self.unconfined:
             md['unconfined'] = self.unconfined
         if md or always_both:
             return b64_data, md
         else:
             return b64_data
 
     def _repr_png_(self):
         if self.embed and self.format == self._FMT_PNG:
             return self._data_and_metadata()
 
     def _repr_jpeg_(self):
         if self.embed and self.format == self._FMT_JPEG:
             return self._data_and_metadata()
 
     def _find_ext(self, s):
         base, ext = splitext(s)
 
         if not ext:
             return base
 
         # `splitext` includes leading period, so we skip it
         return ext[1:].lower()
 
 
 class Video(DisplayObject):
 
     def __init__(self, data=None, url=None, filename=None, embed=False,
                  mimetype=None, width=None, height=None, html_attributes="controls"):
         """Create a video object given raw data or an URL.
 
         When this object is returned by an input cell or passed to the
         display function, it will result in the video being displayed
         in the frontend.
 
         Parameters
         ----------
         data : unicode, str or bytes
             The raw video data or a URL or filename to load the data from.
             Raw data will require passing `embed=True`.
         url : unicode
             A URL for the video. If you specify `url=`,
             the image data will not be embedded.
         filename : unicode
             Path to a local file containing the video.
             Will be interpreted as a local URL unless `embed=True`.
         embed : bool
             Should the video be embedded using a data URI (True) or be
             loaded using a <video> tag (False).
 
             Since videos are large, embedding them should be avoided, if possible.
             You must confirm embedding as your intention by passing `embed=True`.
 
             Local files can be displayed with URLs without embedding the content, via::
 
                 Video('./video.mp4')
 
         mimetype: unicode
             Specify the mimetype for embedded videos.
             Default will be guessed from file extension, if available.
         width : int
             Width in pixels to which to constrain the video in HTML.
             If not supplied, defaults to the width of the video.
         height : int
             Height in pixels to which to constrain the video in html.
             If not supplied, defaults to the height of the video.
         html_attributes : str
             Attributes for the HTML `<video>` block.
             Default: `"controls"` to get video controls.
             Other examples: `"controls muted"` for muted video with controls,
             `"loop autoplay"` for looping autoplaying video without controls.
 
         Examples
         --------
 
         ::
 
             Video('https://archive.org/download/Sita_Sings_the_Blues/Sita_Sings_the_Blues_small.mp4')
             Video('path/to/video.mp4')
             Video('path/to/video.mp4', embed=True)
             Video('path/to/video.mp4', embed=True, html_attributes="controls muted autoplay")
             Video(b'raw-videodata', embed=True)
         """
         if isinstance(data, (Path, PurePath)):
             data = str(data)
 
         if url is None and isinstance(data, str) and data.startswith(('http:', 'https:')):
             url = data
             data = None
         elif os.path.exists(data):
             filename = data
             data = None
 
         if data and not embed:
             msg = ''.join([
                 "To embed videos, you must pass embed=True ",
                 "(this may make your notebook files huge)\n",
                 "Consider passing Video(url='...')",
             ])
             raise ValueError(msg)
 
         self.mimetype = mimetype
         self.embed = embed
         self.width = width
         self.height = height
         self.html_attributes = html_attributes
         super(Video, self).__init__(data=data, url=url, filename=filename)
 
     def _repr_html_(self):
         width = height = ''
         if self.width:
             width = ' width="%d"' % self.width
         if self.height:
             height = ' height="%d"' % self.height
 
         # External URLs and potentially local files are not embedded into the
         # notebook output.
         if not self.embed:
             url = self.url if self.url is not None else self.filename
             output = """<video src="{0}" {1} {2} {3}>
       Your browser does not support the <code>video</code> element.
     </video>""".format(url, self.html_attributes, width, height)
             return output
 
         # Embedded videos are base64-encoded.
         mimetype = self.mimetype
         if self.filename is not None:
             if not mimetype:
                 mimetype, _ = mimetypes.guess_type(self.filename)
 
             with open(self.filename, 'rb') as f:
                 video = f.read()
         else:
             video = self.data
         if isinstance(video, str):
             # unicode input is already b64-encoded
             b64_video = video
         else:
             b64_video = b2a_base64(video).decode('ascii').rstrip()
 
         output = """<video {0} {1} {2}>
  <source src="data:{3};base64,{4}" type="{3}">
  Your browser does not support the video tag.
  </video>""".format(self.html_attributes, width, height, mimetype, b64_video)
         return output
 
     def reload(self):
         # TODO
         pass
 
 
 @skip_doctest
 def set_matplotlib_formats(*formats, **kwargs):
     """Select figure formats for the inline backend. Optionally pass quality for JPEG.
 
     For example, this enables PNG and JPEG output with a JPEG quality of 90%::
 
         In [1]: set_matplotlib_formats('png', 'jpeg', quality=90)
 
     To set this in your config files use the following::
 
         c.InlineBackend.figure_formats = {'png', 'jpeg'}
         c.InlineBackend.print_figure_kwargs.update({'quality' : 90})
 
     Parameters
     ----------
     *formats : strs
         One or more figure formats to enable: 'png', 'retina', 'jpeg', 'svg', 'pdf'.
     **kwargs :
         Keyword args will be relayed to ``figure.canvas.print_figure``.
     """
     from IPython.core.interactiveshell import InteractiveShell
     from IPython.core.pylabtools import select_figure_formats
     # build kwargs, starting with InlineBackend config
     kw = {}
     from ipykernel.pylab.config import InlineBackend
     cfg = InlineBackend.instance()
     kw.update(cfg.print_figure_kwargs)
     kw.update(**kwargs)
     shell = InteractiveShell.instance()
     select_figure_formats(shell, formats, **kw)
 
 @skip_doctest
 def set_matplotlib_close(close=True):
     """Set whether the inline backend closes all figures automatically or not.
 
     By default, the inline backend used in the IPython Notebook will close all
     matplotlib figures automatically after each cell is run. This means that
     plots in different cells won't interfere. Sometimes, you may want to make
     a plot in one cell and then refine it in later cells. This can be accomplished
     by::
 
         In [1]: set_matplotlib_close(False)
 
     To set this in your config files use the following::
 
         c.InlineBackend.close_figures = False
 
     Parameters
     ----------
     close : bool
         Should all matplotlib figures be automatically closed after each cell is
         run?
     """
     from ipykernel.pylab.config import InlineBackend
     cfg = InlineBackend.instance()
     cfg.close_figures = close

IPython/core/page.py

@@ -1,343 +1,343 b''
 # encoding: utf-8
 """
 Paging capabilities for IPython.core
 
 Notes
 -----
 
 For now this uses IPython hooks, so it can't be in IPython.utils.  If we can get
 rid of that dependency, we could move it there.
 -----
 """
 
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
 
 import os
 import io
 import re
 import sys
 import tempfile
 import subprocess
 
 from io import UnsupportedOperation
 
 from IPython import get_ipython
 from IPython.display import display
 from IPython.core.error import TryNext
 from IPython.utils.data import chop
 from IPython.utils.process import system
 from IPython.utils.terminal import get_terminal_size
 from IPython.utils import py3compat
 
 
 def display_page(strng, start=0, screen_lines=25):
     """Just display, no paging. screen_lines is ignored."""
     if isinstance(strng, dict):
         data = strng
     else:
         if start:
             strng = u'\n'.join(strng.splitlines()[start:])
         data = { 'text/plain': strng }
     display(data, raw=True)
 
 
 def as_hook(page_func):
     """Wrap a pager func to strip the `self` arg
     
     so it can be called as a hook.
     """
     return lambda self, *args, **kwargs: page_func(*args, **kwargs)
 
 
 esc_re = re.compile(r"(\x1b[^m]+m)")
 
 def page_dumb(strng, start=0, screen_lines=25):
     """Very dumb 'pager' in Python, for when nothing else works.
 
     Only moves forward, same interface as page(), except for pager_cmd and
     mode.
     """
     if isinstance(strng, dict):
         strng = strng.get('text/plain', '')
     out_ln  = strng.splitlines()[start:]
     screens = chop(out_ln,screen_lines-1)
     if len(screens) == 1:
         print(os.linesep.join(screens[0]))
     else:
         last_escape = ""
         for scr in screens[0:-1]:
             hunk = os.linesep.join(scr)
             print(last_escape + hunk)
             if not page_more():
                 return
             esc_list = esc_re.findall(hunk)
             if len(esc_list) > 0:
                 last_escape = esc_list[-1]
         print(last_escape + os.linesep.join(screens[-1]))
 
 def _detect_screen_size(screen_lines_def):
     """Attempt to work out the number of lines on the screen.
 
     This is called by page(). It can raise an error (e.g. when run in the
     test suite), so it's separated out so it can easily be called in a try block.
     """
     TERM = os.environ.get('TERM',None)
     if not((TERM=='xterm' or TERM=='xterm-color') and sys.platform != 'sunos5'):
         # curses causes problems on many terminals other than xterm, and
         # some termios calls lock up on Sun OS5.
         return screen_lines_def
     
     try:
         import termios
         import curses
     except ImportError:
         return screen_lines_def
     
     # There is a bug in curses, where *sometimes* it fails to properly
     # initialize, and then after the endwin() call is made, the
     # terminal is left in an unusable state.  Rather than trying to
     # check every time for this (by requesting and comparing termios
     # flags each time), we just save the initial terminal state and
     # unconditionally reset it every time.  It's cheaper than making
     # the checks.
     try:
         term_flags = termios.tcgetattr(sys.stdout)
     except termios.error as err:
         # can fail on Linux 2.6, pager_page will catch the TypeError
-        raise TypeError('termios error: {0}'.format(err))
+        raise TypeError('termios error: {0}'.format(err)) from err
 
     try:
         scr = curses.initscr()
     except AttributeError:
         # Curses on Solaris may not be complete, so we can't use it there
         return screen_lines_def
     
     screen_lines_real,screen_cols = scr.getmaxyx()
     curses.endwin()
 
     # Restore terminal state in case endwin() didn't.
     termios.tcsetattr(sys.stdout,termios.TCSANOW,term_flags)
     # Now we have what we needed: the screen size in rows/columns
     return screen_lines_real
     #print '***Screen size:',screen_lines_real,'lines x',\
     #screen_cols,'columns.' # dbg
 
 def pager_page(strng, start=0, screen_lines=0, pager_cmd=None):
     """Display a string, piping through a pager after a certain length.
     
     strng can be a mime-bundle dict, supplying multiple representations,
     keyed by mime-type.
 
     The screen_lines parameter specifies the number of *usable* lines of your
     terminal screen (total lines minus lines you need to reserve to show other
     information).
 
     If you set screen_lines to a number <=0, page() will try to auto-determine
     your screen size and will only use up to (screen_size+screen_lines) for
     printing, paging after that. That is, if you want auto-detection but need
     to reserve the bottom 3 lines of the screen, use screen_lines = -3, and for
     auto-detection without any lines reserved simply use screen_lines = 0.
 
     If a string won't fit in the allowed lines, it is sent through the
     specified pager command. If none given, look for PAGER in the environment,
     and ultimately default to less.
 
     If no system pager works, the string is sent through a 'dumb pager'
     written in python, very simplistic.
     """
     
     # for compatibility with mime-bundle form:
     if isinstance(strng, dict):
         strng = strng['text/plain']
 
     # Ugly kludge, but calling curses.initscr() flat out crashes in emacs
     TERM = os.environ.get('TERM','dumb')
     if TERM in ['dumb','emacs'] and os.name != 'nt':
         print(strng)
         return
     # chop off the topmost part of the string we don't want to see
     str_lines = strng.splitlines()[start:]
     str_toprint = os.linesep.join(str_lines)
     num_newlines = len(str_lines)
     len_str = len(str_toprint)
 
     # Dumb heuristics to guesstimate number of on-screen lines the string
     # takes.  Very basic, but good enough for docstrings in reasonable
     # terminals. If someone later feels like refining it, it's not hard.
     numlines = max(num_newlines,int(len_str/80)+1)
 
     screen_lines_def = get_terminal_size()[1]
 
     # auto-determine screen size
     if screen_lines <= 0:
         try:
             screen_lines += _detect_screen_size(screen_lines_def)
         except (TypeError, UnsupportedOperation):
             print(str_toprint)
             return
 
     #print 'numlines',numlines,'screenlines',screen_lines  # dbg
     if numlines <= screen_lines :
         #print '*** normal print'  # dbg
         print(str_toprint)
     else:
         # Try to open pager and default to internal one if that fails.
         # All failure modes are tagged as 'retval=1', to match the return
         # value of a failed system command.  If any intermediate attempt
         # sets retval to 1, at the end we resort to our own page_dumb() pager.
         pager_cmd = get_pager_cmd(pager_cmd)
         pager_cmd += ' ' + get_pager_start(pager_cmd,start)
         if os.name == 'nt':
             if pager_cmd.startswith('type'):
                 # The default WinXP 'type' command is failing on complex strings.
                 retval = 1
             else:
                 fd, tmpname = tempfile.mkstemp('.txt')
                 try:
                     os.close(fd)
                     with open(tmpname, 'wt') as tmpfile:
                         tmpfile.write(strng)
                         cmd = "%s < %s" % (pager_cmd, tmpname)
                     # tmpfile needs to be closed for windows
                     if os.system(cmd):
                         retval = 1
                     else:
                         retval = None
                 finally:
                     os.remove(tmpname)
         else:
             try:
                 retval = None
                 # Emulate os.popen, but redirect stderr
                 proc = subprocess.Popen(pager_cmd,
                                 shell=True,
                                 stdin=subprocess.PIPE,
                                 stderr=subprocess.DEVNULL
                                 )
                 pager = os._wrap_close(io.TextIOWrapper(proc.stdin), proc)
                 try:
                     pager_encoding = pager.encoding or sys.stdout.encoding
                     pager.write(strng)
                 finally:
                     retval = pager.close()
             except IOError as msg:  # broken pipe when user quits
                 if msg.args == (32, 'Broken pipe'):
                     retval = None
                 else:
                     retval = 1
             except OSError:
                 # Other strange problems, sometimes seen in Win2k/cygwin
                 retval = 1
         if retval is not None:
             page_dumb(strng,screen_lines=screen_lines)
 
 
 def page(data, start=0, screen_lines=0, pager_cmd=None):
     """Display content in a pager, piping through a pager after a certain length.
     
     data can be a mime-bundle dict, supplying multiple representations,
     keyed by mime-type, or text.
     
     Pager is dispatched via the `show_in_pager` IPython hook.
     If no hook is registered, `pager_page` will be used.
     """
     # Some routines may auto-compute start offsets incorrectly and pass a
     # negative value.  Offset to 0 for robustness.
     start = max(0, start)
 
     # first, try the hook
     ip = get_ipython()
     if ip:
         try:
             ip.hooks.show_in_pager(data, start=start, screen_lines=screen_lines)
             return
         except TryNext:
             pass
     
     # fallback on default pager
     return pager_page(data, start, screen_lines, pager_cmd)
 
 
 def page_file(fname, start=0, pager_cmd=None):
     """Page a file, using an optional pager command and starting line.
     """
 
     pager_cmd = get_pager_cmd(pager_cmd)
     pager_cmd += ' ' + get_pager_start(pager_cmd,start)
 
     try:
         if os.environ['TERM'] in ['emacs','dumb']:
             raise EnvironmentError
         system(pager_cmd + ' ' + fname)
     except:
         try:
             if start > 0:
                 start -= 1
             page(open(fname).read(),start)
         except:
             print('Unable to show file',repr(fname))
 
 
 def get_pager_cmd(pager_cmd=None):
     """Return a pager command.
 
     Makes some attempts at finding an OS-correct one.
     """
     if os.name == 'posix':
         default_pager_cmd = 'less -R'  # -R for color control sequences
     elif os.name in ['nt','dos']:
         default_pager_cmd = 'type'
 
     if pager_cmd is None:
         try:
             pager_cmd = os.environ['PAGER']
         except:
             pager_cmd = default_pager_cmd
     
     if pager_cmd == 'less' and '-r' not in os.environ.get('LESS', '').lower():
         pager_cmd += ' -R'
     
     return pager_cmd
 
 
 def get_pager_start(pager, start):
     """Return the string for paging files with an offset.
 
     This is the '+N' argument which less and more (under Unix) accept.
     """
 
     if pager in ['less','more']:
         if start:
             start_string = '+' + str(start)
         else:
             start_string = ''
     else:
         start_string = ''
     return start_string
 
 
 # (X)emacs on win32 doesn't like to be bypassed with msvcrt.getch()
 if os.name == 'nt' and os.environ.get('TERM','dumb') != 'emacs':
     import msvcrt
     def page_more():
         """ Smart pausing between pages
 
         @return:    True if need print more lines, False if quit
         """
         sys.stdout.write('---Return to continue, q to quit--- ')
         ans = msvcrt.getwch()
         if ans in ("q", "Q"):
             result = False
         else:
             result = True
         sys.stdout.write("\b"*37 + " "*37 + "\b"*37)
         return result
 else:
     def page_more():
         ans = py3compat.input('---Return to continue, q to quit--- ')
         if ans.lower().startswith('q'):
             return False
         else:
             return True

IPython/core/pylabtools.py

@@ -1,419 +1,419 b''
 # -*- coding: utf-8 -*-
 """Pylab (matplotlib) support utilities."""
 
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
 from io import BytesIO
 
 from IPython.core.display import _pngxy
 from IPython.utils.decorators import flag_calls
 
 # If user specifies a GUI, that dictates the backend, otherwise we read the
 # user's mpl default from the mpl rc structure
 backends = {'tk': 'TkAgg',
             'gtk': 'GTKAgg',
             'gtk3': 'GTK3Agg',
             'wx': 'WXAgg',
             'qt4': 'Qt4Agg',
             'qt5': 'Qt5Agg',
             'qt': 'Qt5Agg',
             'osx': 'MacOSX',
             'nbagg': 'nbAgg',
             'notebook': 'nbAgg',
             'agg': 'agg',
             'svg': 'svg',
             'pdf': 'pdf',
             'ps': 'ps',
             'inline': 'module://ipykernel.pylab.backend_inline',
             'ipympl': 'module://ipympl.backend_nbagg',
             'widget': 'module://ipympl.backend_nbagg',
             }
 
 # We also need a reverse backends2guis mapping that will properly choose which
 # GUI support to activate based on the desired matplotlib backend.  For the
 # most part it's just a reverse of the above dict, but we also need to add a
 # few others that map to the same GUI manually:
 backend2gui = dict(zip(backends.values(), backends.keys()))
 # Our tests expect backend2gui to just return 'qt'
 backend2gui['Qt4Agg'] = 'qt'
 # In the reverse mapping, there are a few extra valid matplotlib backends that
 # map to the same GUI support
 backend2gui['GTK'] = backend2gui['GTKCairo'] = 'gtk'
 backend2gui['GTK3Cairo'] = 'gtk3'
 backend2gui['WX'] = 'wx'
 backend2gui['CocoaAgg'] = 'osx'
 # And some backends that don't need GUI integration
 del backend2gui['nbAgg']
 del backend2gui['agg']
 del backend2gui['svg']
 del backend2gui['pdf']
 del backend2gui['ps']
 del backend2gui['module://ipykernel.pylab.backend_inline']
 
 #-----------------------------------------------------------------------------
 # Matplotlib utilities
 #-----------------------------------------------------------------------------
 
 
 def getfigs(*fig_nums):
     """Get a list of matplotlib figures by figure numbers.
 
     If no arguments are given, all available figures are returned.  If the
     argument list contains references to invalid figures, a warning is printed
     but the function continues pasting further figures.
 
     Parameters
     ----------
     figs : tuple
         A tuple of ints giving the figure numbers of the figures to return.
     """
     from matplotlib._pylab_helpers import Gcf
     if not fig_nums:
         fig_managers = Gcf.get_all_fig_managers()
         return [fm.canvas.figure for fm in fig_managers]
     else:
         figs = []
         for num in fig_nums:
             f = Gcf.figs.get(num)
             if f is None:
                 print('Warning: figure %s not available.' % num)
             else:
                 figs.append(f.canvas.figure)
         return figs
 
 
 def figsize(sizex, sizey):
     """Set the default figure size to be [sizex, sizey].
 
     This is just an easy to remember, convenience wrapper that sets::
 
       matplotlib.rcParams['figure.figsize'] = [sizex, sizey]
     """
     import matplotlib
     matplotlib.rcParams['figure.figsize'] = [sizex, sizey]
 
 
 def print_figure(fig, fmt='png', bbox_inches='tight', **kwargs):
     """Print a figure to an image, and return the resulting file data
     
     Returned data will be bytes unless ``fmt='svg'``,
     in which case it will be unicode.
     
     Any keyword args are passed to fig.canvas.print_figure,
     such as ``quality`` or ``bbox_inches``.
     """
     # When there's an empty figure, we shouldn't return anything, otherwise we
     # get big blank areas in the qt console.
     if not fig.axes and not fig.lines:
         return
 
     dpi = fig.dpi
     if fmt == 'retina':
         dpi = dpi * 2
         fmt = 'png'
     
     # build keyword args
     kw = {
         "format":fmt,
         "facecolor":fig.get_facecolor(),
         "edgecolor":fig.get_edgecolor(),
         "dpi":dpi,
         "bbox_inches":bbox_inches,
     }
     # **kwargs get higher priority
     kw.update(kwargs)
 
     bytes_io = BytesIO()
     if fig.canvas is None:
         from matplotlib.backend_bases import FigureCanvasBase
         FigureCanvasBase(fig)
 
     fig.canvas.print_figure(bytes_io, **kw)
     data = bytes_io.getvalue()
     if fmt == 'svg':
         data = data.decode('utf-8')
     return data
 
 def retina_figure(fig, **kwargs):
     """format a figure as a pixel-doubled (retina) PNG"""
     pngdata = print_figure(fig, fmt='retina', **kwargs)
     # Make sure that retina_figure acts just like print_figure and returns
     # None when the figure is empty.
     if pngdata is None:
         return
     w, h = _pngxy(pngdata)
     metadata = {"width": w//2, "height":h//2}
     return pngdata, metadata
 
 # We need a little factory function here to create the closure where
 # safe_execfile can live.
 def mpl_runner(safe_execfile):
     """Factory to return a matplotlib-enabled runner for %run.
 
     Parameters
     ----------
     safe_execfile : function
       This must be a function with the same interface as the
       :meth:`safe_execfile` method of IPython.
 
     Returns
     -------
     A function suitable for use as the ``runner`` argument of the %run magic
     function.
     """
     
     def mpl_execfile(fname,*where,**kw):
         """matplotlib-aware wrapper around safe_execfile.
 
         Its interface is identical to that of the :func:`execfile` builtin.
 
         This is ultimately a call to execfile(), but wrapped in safeties to
         properly handle interactive rendering."""
 
         import matplotlib
         import matplotlib.pyplot as plt
 
         #print '*** Matplotlib runner ***' # dbg
         # turn off rendering until end of script
         is_interactive = matplotlib.rcParams['interactive']
         matplotlib.interactive(False)
         safe_execfile(fname,*where,**kw)
         matplotlib.interactive(is_interactive)
         # make rendering call now, if the user tried to do it
         if plt.draw_if_interactive.called:
             plt.draw()
             plt.draw_if_interactive.called = False
 
         # re-draw everything that is stale
         try:
             da = plt.draw_all
         except AttributeError:
             pass
         else:
             da()
 
     return mpl_execfile
 
 
 def _reshow_nbagg_figure(fig):
     """reshow an nbagg figure"""
     try:
         reshow = fig.canvas.manager.reshow
-    except AttributeError:
-        raise NotImplementedError()
+    except AttributeError as e:
+        raise NotImplementedError() from e
     else:
         reshow()
 
 
 def select_figure_formats(shell, formats, **kwargs):
     """Select figure formats for the inline backend.
 
     Parameters
     ==========
     shell : InteractiveShell
         The main IPython instance.
     formats : str or set
         One or a set of figure formats to enable: 'png', 'retina', 'jpeg', 'svg', 'pdf'.
     **kwargs : any
         Extra keyword arguments to be passed to fig.canvas.print_figure.
     """
     import matplotlib
     from matplotlib.figure import Figure
 
     svg_formatter = shell.display_formatter.formatters['image/svg+xml']
     png_formatter = shell.display_formatter.formatters['image/png']
     jpg_formatter = shell.display_formatter.formatters['image/jpeg']
     pdf_formatter = shell.display_formatter.formatters['application/pdf']
 
     if isinstance(formats, str):
         formats = {formats}
     # cast in case of list / tuple
     formats = set(formats)
 
     [ f.pop(Figure, None) for f in shell.display_formatter.formatters.values() ]
     mplbackend = matplotlib.get_backend().lower()
     if mplbackend == 'nbagg' or mplbackend == 'module://ipympl.backend_nbagg':
         formatter = shell.display_formatter.ipython_display_formatter
         formatter.for_type(Figure, _reshow_nbagg_figure)
 
     supported = {'png', 'png2x', 'retina', 'jpg', 'jpeg', 'svg', 'pdf'}
     bad = formats.difference(supported)
     if bad:
         bs = "%s" % ','.join([repr(f) for f in bad])
         gs = "%s" % ','.join([repr(f) for f in supported])
         raise ValueError("supported formats are: %s not %s" % (gs, bs))
     
     if 'png' in formats:
         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
     if 'retina' in formats or 'png2x' in formats:
         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))
     if 'jpg' in formats or 'jpeg' in formats:
         jpg_formatter.for_type(Figure, lambda fig: print_figure(fig, 'jpg', **kwargs))
     if 'svg' in formats:
         svg_formatter.for_type(Figure, lambda fig: print_figure(fig, 'svg', **kwargs))
     if 'pdf' in formats:
         pdf_formatter.for_type(Figure, lambda fig: print_figure(fig, 'pdf', **kwargs))
 
 #-----------------------------------------------------------------------------
 # Code for initializing matplotlib and importing pylab
 #-----------------------------------------------------------------------------
 
 
 def find_gui_and_backend(gui=None, gui_select=None):
     """Given a gui string return the gui and mpl backend.
 
     Parameters
     ----------
     gui : str
         Can be one of ('tk','gtk','wx','qt','qt4','inline','agg').
     gui_select : str
         Can be one of ('tk','gtk','wx','qt','qt4','inline').
         This is any gui already selected by the shell.
 
     Returns
     -------
     A tuple of (gui, backend) where backend is one of ('TkAgg','GTKAgg',
     'WXAgg','Qt4Agg','module://ipykernel.pylab.backend_inline','agg').
     """
 
     import matplotlib
 
     if gui and gui != 'auto':
         # select backend based on requested gui
         backend = backends[gui]
         if gui == 'agg':
             gui = None
     else:
         # We need to read the backend from the original data structure, *not*
         # from mpl.rcParams, since a prior invocation of %matplotlib may have
         # overwritten that.
         # WARNING: this assumes matplotlib 1.1 or newer!!
         backend = matplotlib.rcParamsOrig['backend']
         # In this case, we need to find what the appropriate gui selection call
         # should be for IPython, so we can activate inputhook accordingly
         gui = backend2gui.get(backend, None)
 
         # If we have already had a gui active, we need it and inline are the
         # ones allowed.
         if gui_select and gui != gui_select:
             gui = gui_select
             backend = backends[gui]
 
     return gui, backend
 
 
 def activate_matplotlib(backend):
     """Activate the given backend and set interactive to True."""
 
     import matplotlib
     matplotlib.interactive(True)
     
     # Matplotlib had a bug where even switch_backend could not force
     # the rcParam to update. This needs to be set *before* the module
     # magic of switch_backend().
     matplotlib.rcParams['backend'] = backend
 
     # Due to circular imports, pyplot may be only partially initialised
     # when this function runs.
     # So avoid needing matplotlib attribute-lookup to access pyplot.
     from matplotlib import pyplot as plt
 
     plt.switch_backend(backend)
 
     plt.show._needmain = False
     # We need to detect at runtime whether show() is called by the user.
     # For this, we wrap it into a decorator which adds a 'called' flag.
     plt.draw_if_interactive = flag_calls(plt.draw_if_interactive)
 
 
 def import_pylab(user_ns, import_all=True):
     """Populate the namespace with pylab-related values.
     
     Imports matplotlib, pylab, numpy, and everything from pylab and numpy.
     
     Also imports a few names from IPython (figsize, display, getfigs)
     
     """
 
     # Import numpy as np/pyplot as plt are conventions we're trying to
     # somewhat standardize on.  Making them available to users by default
     # will greatly help this.
     s = ("import numpy\n"
           "import matplotlib\n"
           "from matplotlib import pylab, mlab, pyplot\n"
           "np = numpy\n"
           "plt = pyplot\n"
           )
     exec(s, user_ns)
     
     if import_all:
         s = ("from matplotlib.pylab import *\n"
              "from numpy import *\n")
         exec(s, user_ns)
     
     # IPython symbols to add
     user_ns['figsize'] = figsize
     from IPython.display import display
     # Add display and getfigs to the user's namespace
     user_ns['display'] = display
     user_ns['getfigs'] = getfigs
 
 
 def configure_inline_support(shell, backend):
     """Configure an IPython shell object for matplotlib use.
 
     Parameters
     ----------
     shell : InteractiveShell instance
 
     backend : matplotlib backend
     """
     # If using our svg payload backend, register the post-execution
     # function that will pick up the results for display.  This can only be
     # done with access to the real shell object.
 
     # Note: if we can't load the inline backend, then there's no point
     # continuing (such as in terminal-only shells in environments without
     # zeromq available).
     try:
         from ipykernel.pylab.backend_inline import InlineBackend
     except ImportError:
         return
     import matplotlib
 
     cfg = InlineBackend.instance(parent=shell)
     cfg.shell = shell
     if cfg not in shell.configurables:
         shell.configurables.append(cfg)
 
     if backend == backends['inline']:
         from ipykernel.pylab.backend_inline import flush_figures
         shell.events.register('post_execute', flush_figures)
 
         # Save rcParams that will be overwrittern
         shell._saved_rcParams = {}
         for k in cfg.rc:
             shell._saved_rcParams[k] = matplotlib.rcParams[k]
         # load inline_rc
         matplotlib.rcParams.update(cfg.rc)
         new_backend_name = "inline"
     else:
         from ipykernel.pylab.backend_inline import flush_figures
         try:
             shell.events.unregister('post_execute', flush_figures)
         except ValueError:
             pass
         if hasattr(shell, '_saved_rcParams'):
             matplotlib.rcParams.update(shell._saved_rcParams)
             del shell._saved_rcParams
         new_backend_name = "other"
 
     # only enable the formats once -> don't change the enabled formats (which the user may
     # has changed) when getting another "%matplotlib inline" call.
     # See https://github.com/ipython/ipykernel/issues/29
     cur_backend = getattr(configure_inline_support, "current_backend", "unset")
     if new_backend_name != cur_backend:
         # Setup the default figure format
         select_figure_formats(shell, cfg.figure_formats, **cfg.print_figure_kwargs)
         configure_inline_support.current_backend = new_backend_name

IPython/core/tests/test_pylabtools.py

@@ -1,256 +1,256 b''
 """Tests for pylab tools module.
 """
 
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
 
 from io import UnsupportedOperation, BytesIO
 
 import matplotlib
 matplotlib.use('Agg')
 from matplotlib.figure import Figure
 
 from nose import SkipTest
 import nose.tools as nt
 
 from matplotlib import pyplot as plt
 import numpy as np
 
 from IPython.core.getipython import get_ipython
 from IPython.core.interactiveshell import InteractiveShell
 from IPython.core.display import _PNG, _JPEG
 from .. import pylabtools as pt
 
 from IPython.testing import decorators as dec
 
 
 def test_figure_to_svg():
     # simple empty-figure test
     fig = plt.figure()
     nt.assert_equal(pt.print_figure(fig, 'svg'), None)
 
     plt.close('all')
 
     # simple check for at least svg-looking output
     fig = plt.figure()
     ax = fig.add_subplot(1,1,1)
     ax.plot([1,2,3])
     plt.draw()
     svg = pt.print_figure(fig, 'svg')[:100].lower()
     nt.assert_in(u'doctype svg', svg)
 
 def _check_pil_jpeg_bytes():
     """Skip if PIL can't write JPEGs to BytesIO objects"""
     # PIL's JPEG plugin can't write to BytesIO objects
     # Pillow fixes this
     from PIL import Image
     buf = BytesIO()
     img = Image.new("RGB", (4,4))
     try:
         img.save(buf, 'jpeg')
     except Exception as e:
         ename = e.__class__.__name__
-        raise SkipTest("PIL can't write JPEG to BytesIO: %s: %s" % (ename, e))
+        raise SkipTest("PIL can't write JPEG to BytesIO: %s: %s" % (ename, e)) from e
 
 @dec.skip_without("PIL.Image")
 def test_figure_to_jpeg():
     _check_pil_jpeg_bytes()
     # simple check for at least jpeg-looking output
     fig = plt.figure()
     ax = fig.add_subplot(1,1,1)
     ax.plot([1,2,3])
     plt.draw()
     jpeg = pt.print_figure(fig, 'jpeg', pil_kwargs={'optimize': 50})[:100].lower()
     assert jpeg.startswith(_JPEG)
 
 def test_retina_figure():
     # simple empty-figure test
     fig = plt.figure()
     nt.assert_equal(pt.retina_figure(fig), None)
     plt.close('all')
 
     fig = plt.figure()
     ax = fig.add_subplot(1,1,1)
     ax.plot([1,2,3])
     plt.draw()
     png, md = pt.retina_figure(fig)
     assert png.startswith(_PNG)
     nt.assert_in('width', md)
     nt.assert_in('height', md)
 
 _fmt_mime_map = {
     'png': 'image/png',
     'jpeg': 'image/jpeg',
     'pdf': 'application/pdf',
     'retina': 'image/png',
     'svg': 'image/svg+xml',
 }
 
 def test_select_figure_formats_str():
     ip = get_ipython()
     for fmt, active_mime in _fmt_mime_map.items():
         pt.select_figure_formats(ip, fmt)
         for mime, f in ip.display_formatter.formatters.items():
             if mime == active_mime:
                 nt.assert_in(Figure, f)
             else:
                 nt.assert_not_in(Figure, f)
 
 def test_select_figure_formats_kwargs():
     ip = get_ipython()
     kwargs = dict(quality=10, bbox_inches='tight')
     pt.select_figure_formats(ip, 'png', **kwargs)
     formatter = ip.display_formatter.formatters['image/png']
     f = formatter.lookup_by_type(Figure)
     cell = f.__closure__[0].cell_contents
     nt.assert_equal(cell, kwargs)
 
     # check that the formatter doesn't raise
     fig = plt.figure()
     ax = fig.add_subplot(1,1,1)
     ax.plot([1,2,3])
     plt.draw()
     formatter.enabled = True
     png = formatter(fig)
     assert png.startswith(_PNG)
 
 def test_select_figure_formats_set():
     ip = get_ipython()
     for fmts in [
         {'png', 'svg'},
         ['png'],
         ('jpeg', 'pdf', 'retina'),
         {'svg'},
     ]:
         active_mimes = {_fmt_mime_map[fmt] for fmt in fmts}
         pt.select_figure_formats(ip, fmts)
         for mime, f in ip.display_formatter.formatters.items():
             if mime in active_mimes:
                 nt.assert_in(Figure, f)
             else:
                 nt.assert_not_in(Figure, f)
 
 def test_select_figure_formats_bad():
     ip = get_ipython()
     with nt.assert_raises(ValueError):
         pt.select_figure_formats(ip, 'foo')
     with nt.assert_raises(ValueError):
         pt.select_figure_formats(ip, {'png', 'foo'})
     with nt.assert_raises(ValueError):
         pt.select_figure_formats(ip, ['retina', 'pdf', 'bar', 'bad'])
 
 def test_import_pylab():
     ns = {}
     pt.import_pylab(ns, import_all=False)
     nt.assert_true('plt' in ns)
     nt.assert_equal(ns['np'], np)
 
 class TestPylabSwitch(object):
     class Shell(InteractiveShell):
         def enable_gui(self, gui):
             pass
 
     def setup(self):
         import matplotlib
         def act_mpl(backend):
             matplotlib.rcParams['backend'] = backend
 
         # Save rcParams since they get modified
         self._saved_rcParams = matplotlib.rcParams
         self._saved_rcParamsOrig = matplotlib.rcParamsOrig
         matplotlib.rcParams = dict(backend='Qt4Agg')
         matplotlib.rcParamsOrig = dict(backend='Qt4Agg')
 
         # Mock out functions
         self._save_am = pt.activate_matplotlib
         pt.activate_matplotlib = act_mpl
         self._save_ip = pt.import_pylab
         pt.import_pylab = lambda *a,**kw:None
         self._save_cis = pt.configure_inline_support
         pt.configure_inline_support = lambda *a,**kw:None
 
     def teardown(self):
         pt.activate_matplotlib = self._save_am
         pt.import_pylab = self._save_ip
         pt.configure_inline_support = self._save_cis
         import matplotlib
         matplotlib.rcParams = self._saved_rcParams
         matplotlib.rcParamsOrig = self._saved_rcParamsOrig
 
     def test_qt(self):
         s = self.Shell()
         gui, backend = s.enable_matplotlib(None)
         nt.assert_equal(gui, 'qt')
         nt.assert_equal(s.pylab_gui_select, 'qt')
 
         gui, backend = s.enable_matplotlib('inline')
         nt.assert_equal(gui, 'inline')
         nt.assert_equal(s.pylab_gui_select, 'qt')
 
         gui, backend = s.enable_matplotlib('qt')
         nt.assert_equal(gui, 'qt')
         nt.assert_equal(s.pylab_gui_select, 'qt')
 
         gui, backend = s.enable_matplotlib('inline')
         nt.assert_equal(gui, 'inline')
         nt.assert_equal(s.pylab_gui_select, 'qt')
 
         gui, backend = s.enable_matplotlib()
         nt.assert_equal(gui, 'qt')
         nt.assert_equal(s.pylab_gui_select, 'qt')
 
     def test_inline(self):
         s = self.Shell()
         gui, backend = s.enable_matplotlib('inline')
         nt.assert_equal(gui, 'inline')
         nt.assert_equal(s.pylab_gui_select, None)
 
         gui, backend = s.enable_matplotlib('inline')
         nt.assert_equal(gui, 'inline')
         nt.assert_equal(s.pylab_gui_select, None)
 
         gui, backend = s.enable_matplotlib('qt')
         nt.assert_equal(gui, 'qt')
         nt.assert_equal(s.pylab_gui_select, 'qt')
 
     def test_inline_twice(self):
         "Using '%matplotlib inline' twice should not reset formatters"
 
         ip = self.Shell()
         gui, backend = ip.enable_matplotlib('inline')
         nt.assert_equal(gui, 'inline')
 
         fmts =  {'png'}
         active_mimes = {_fmt_mime_map[fmt] for fmt in fmts}
         pt.select_figure_formats(ip, fmts)
 
         gui, backend = ip.enable_matplotlib('inline')
         nt.assert_equal(gui, 'inline')
 
         for mime, f in ip.display_formatter.formatters.items():
             if mime in active_mimes:
                 nt.assert_in(Figure, f)
             else:
                 nt.assert_not_in(Figure, f)
 
     def test_qt_gtk(self):
         s = self.Shell()
         gui, backend = s.enable_matplotlib('qt')
         nt.assert_equal(gui, 'qt')
         nt.assert_equal(s.pylab_gui_select, 'qt')
 
         gui, backend = s.enable_matplotlib('gtk')
         nt.assert_equal(gui, 'qt')
         nt.assert_equal(s.pylab_gui_select, 'qt')
 
 
 def test_no_gui_backends():
     for k in ['agg', 'svg', 'pdf', 'ps']:
         assert k not in pt.backend2gui
 
 
 def test_figure_no_canvas():
     fig = Figure()
     fig.canvas = None
     pt.print_figure(fig)

IPython/core/tests/test_run.py

@@ -1,601 +1,601 b''
 # encoding: utf-8
 """Tests for code execution (%run and related), which is particularly tricky.
 
 Because of how %run manages namespaces, and the fact that we are trying here to
 verify subtle object deletion and reference counting issues, the %run tests
 will be kept in this separate file.  This makes it easier to aggregate in one
 place the tricks needed to handle it; most other magics are much easier to test
 and we do so in a common test_magic file.
 
 Note that any test using `run -i` should make sure to do a `reset` afterwards,
 as otherwise it may influence later tests.
 """
 
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
 
 
 import functools
 import os
 from os.path import join as pjoin
 import random
 import string
 import sys
 import textwrap
 import unittest
 from unittest.mock import patch
 
 import nose.tools as nt
 from nose import SkipTest
 
 from IPython.testing import decorators as dec
 from IPython.testing import tools as tt
 from IPython.utils.io import capture_output
 from IPython.utils.tempdir import TemporaryDirectory
 from IPython.core import debugger
 
 def doctest_refbug():
     """Very nasty problem with references held by multiple runs of a script.
     See: https://github.com/ipython/ipython/issues/141
 
     In [1]: _ip.clear_main_mod_cache()
     # random
 
     In [2]: %run refbug
 
     In [3]: call_f()
     lowercased: hello
 
     In [4]: %run refbug
 
     In [5]: call_f()
     lowercased: hello
     lowercased: hello
     """
 
 
 def doctest_run_builtins():
     r"""Check that %run doesn't damage __builtins__.
 
     In [1]: import tempfile
 
     In [2]: bid1 = id(__builtins__)
 
     In [3]: fname = tempfile.mkstemp('.py')[1]
 
     In [3]: f = open(fname,'w')
 
     In [4]: dummy= f.write('pass\n')
 
     In [5]: f.flush()
 
     In [6]: t1 = type(__builtins__)
 
     In [7]: %run $fname
 
     In [7]: f.close()
 
     In [8]: bid2 = id(__builtins__)
 
     In [9]: t2 = type(__builtins__)
 
     In [10]: t1 == t2
     Out[10]: True
 
     In [10]: bid1 == bid2
     Out[10]: True
 
     In [12]: try:
        ....:     os.unlink(fname)
        ....: except:
        ....:     pass
        ....:
     """
 
 
 def doctest_run_option_parser():
     r"""Test option parser in %run.
 
     In [1]: %run print_argv.py
     []
 
     In [2]: %run print_argv.py print*.py
     ['print_argv.py']
 
     In [3]: %run -G print_argv.py print*.py
     ['print*.py']
 
     """
 
 
 @dec.skip_win32
 def doctest_run_option_parser_for_posix():
     r"""Test option parser in %run (Linux/OSX specific).
 
     You need double quote to escape glob in POSIX systems:
 
     In [1]: %run print_argv.py print\\*.py
     ['print*.py']
 
     You can't use quote to escape glob in POSIX systems:
 
     In [2]: %run print_argv.py 'print*.py'
     ['print_argv.py']
 
     """
 
 
 @dec.skip_if_not_win32
 def doctest_run_option_parser_for_windows():
     r"""Test option parser in %run (Windows specific).
 
     In Windows, you can't escape ``*` `by backslash:
 
     In [1]: %run print_argv.py print\\*.py
     ['print\\*.py']
 
     You can use quote to escape glob:
 
     In [2]: %run print_argv.py 'print*.py'
     ['print*.py']
 
     """
 
 
 def doctest_reset_del():
     """Test that resetting doesn't cause errors in __del__ methods.
 
     In [2]: class A(object):
        ...:     def __del__(self):
        ...:         print(str("Hi"))
        ...:
 
     In [3]: a = A()
 
     In [4]: get_ipython().reset()
     Hi
 
     In [5]: 1+1
     Out[5]: 2
     """
 
 # For some tests, it will be handy to organize them in a class with a common
 # setup that makes a temp file
 
 class TestMagicRunPass(tt.TempFileMixin):
 
     def setUp(self):
         content = "a = [1,2,3]\nb = 1"
         self.mktmp(content)
         
     def run_tmpfile(self):
         _ip = get_ipython()
         # This fails on Windows if self.tmpfile.name has spaces or "~" in it.
         # See below and ticket https://bugs.launchpad.net/bugs/366353
         _ip.magic('run %s' % self.fname)
         
     def run_tmpfile_p(self):
         _ip = get_ipython()
         # This fails on Windows if self.tmpfile.name has spaces or "~" in it.
         # See below and ticket https://bugs.launchpad.net/bugs/366353
         _ip.magic('run -p %s' % self.fname)
 
     def test_builtins_id(self):
         """Check that %run doesn't damage __builtins__ """
         _ip = get_ipython()
         # Test that the id of __builtins__ is not modified by %run
         bid1 = id(_ip.user_ns['__builtins__'])
         self.run_tmpfile()
         bid2 = id(_ip.user_ns['__builtins__'])
         nt.assert_equal(bid1, bid2)
 
     def test_builtins_type(self):
         """Check that the type of __builtins__ doesn't change with %run.
 
         However, the above could pass if __builtins__ was already modified to
         be a dict (it should be a module) by a previous use of %run.  So we
         also check explicitly that it really is a module:
         """
         _ip = get_ipython()
         self.run_tmpfile()
         nt.assert_equal(type(_ip.user_ns['__builtins__']),type(sys))
         
     def test_run_profile( self ):
         """Test that the option -p, which invokes the profiler, do not
         crash by invoking execfile"""
         self.run_tmpfile_p()
 
     def test_run_debug_twice(self):
         # https://github.com/ipython/ipython/issues/10028
         _ip = get_ipython()
         with tt.fake_input(['c']):
             _ip.magic('run -d %s' % self.fname)
         with tt.fake_input(['c']):
             _ip.magic('run -d %s' % self.fname)
 
     def test_run_debug_twice_with_breakpoint(self):
         """Make a valid python temp file."""
         _ip = get_ipython()
         with tt.fake_input(['b 2', 'c', 'c']):
             _ip.magic('run -d %s' % self.fname)
 
         with tt.fake_input(['c']):
             with tt.AssertNotPrints('KeyError'):
                 _ip.magic('run -d %s' % self.fname)
 
 
 class TestMagicRunSimple(tt.TempFileMixin):
 
     def test_simpledef(self):
         """Test that simple class definitions work."""
         src = ("class foo: pass\n"
                "def f(): return foo()")
         self.mktmp(src)
         _ip.magic('run %s' % self.fname)
         _ip.run_cell('t = isinstance(f(), foo)')
         nt.assert_true(_ip.user_ns['t'])
 
     def test_obj_del(self):
         """Test that object's __del__ methods are called on exit."""
         if sys.platform == 'win32':
             try:
                 import win32api
-            except ImportError:
-                raise SkipTest("Test requires pywin32")
+            except ImportError as e:
+                raise SkipTest("Test requires pywin32") from e
         src = ("class A(object):\n"
                "    def __del__(self):\n"
                "        print('object A deleted')\n"
                "a = A()\n")
         self.mktmp(src)
         err = None
         tt.ipexec_validate(self.fname, 'object A deleted', err)
     
     def test_aggressive_namespace_cleanup(self):
         """Test that namespace cleanup is not too aggressive GH-238
 
         Returning from another run magic deletes the namespace"""
         # see ticket https://github.com/ipython/ipython/issues/238
         
         with tt.TempFileMixin() as empty:
             empty.mktmp('')
             # On Windows, the filename will have \users in it, so we need to use the
             # repr so that the \u becomes \\u.
             src = ("ip = get_ipython()\n"
                    "for i in range(5):\n"
                    "   try:\n"
                    "       ip.magic(%r)\n"
                    "   except NameError as e:\n"
                    "       print(i)\n"
                    "       break\n" % ('run ' + empty.fname))
             self.mktmp(src)
             _ip.magic('run %s' % self.fname)
             _ip.run_cell('ip == get_ipython()')
             nt.assert_equal(_ip.user_ns['i'], 4)
     
     def test_run_second(self):
         """Test that running a second file doesn't clobber the first, gh-3547
         """
         self.mktmp("avar = 1\n"
                    "def afunc():\n"
                    "  return avar\n")
 
         with tt.TempFileMixin() as empty:
             empty.mktmp("")
             
             _ip.magic('run %s' % self.fname)
             _ip.magic('run %s' % empty.fname)
             nt.assert_equal(_ip.user_ns['afunc'](), 1)
 
     @dec.skip_win32
     def test_tclass(self):
         mydir = os.path.dirname(__file__)
         tc = os.path.join(mydir, 'tclass')
         src = ("%%run '%s' C-first\n"
                "%%run '%s' C-second\n"
                "%%run '%s' C-third\n") % (tc, tc, tc)
         self.mktmp(src, '.ipy')
         out = """\
 ARGV 1-: ['C-first']
 ARGV 1-: ['C-second']
 tclass.py: deleting object: C-first
 ARGV 1-: ['C-third']
 tclass.py: deleting object: C-second
 tclass.py: deleting object: C-third
 """
         err = None
         tt.ipexec_validate(self.fname, out, err)
 
     def test_run_i_after_reset(self):
         """Check that %run -i still works after %reset (gh-693)"""
         src = "yy = zz\n"
         self.mktmp(src)
         _ip.run_cell("zz = 23")
         try:
             _ip.magic('run -i %s' % self.fname)
             nt.assert_equal(_ip.user_ns['yy'], 23)
         finally:
             _ip.magic('reset -f')
             
         _ip.run_cell("zz = 23")
         try:
             _ip.magic('run -i %s' % self.fname)
             nt.assert_equal(_ip.user_ns['yy'], 23)
         finally:
             _ip.magic('reset -f')
             
     def test_unicode(self):
         """Check that files in odd encodings are accepted."""
         mydir = os.path.dirname(__file__)
         na = os.path.join(mydir, 'nonascii.py')
         _ip.magic('run "%s"' % na)
         nt.assert_equal(_ip.user_ns['u'], u'Ўт№Ф')
 
     def test_run_py_file_attribute(self):
         """Test handling of `__file__` attribute in `%run <file>.py`."""
         src = "t = __file__\n"
         self.mktmp(src)
         _missing = object()
         file1 = _ip.user_ns.get('__file__', _missing)
         _ip.magic('run %s' % self.fname)
         file2 = _ip.user_ns.get('__file__', _missing)
 
         # Check that __file__ was equal to the filename in the script's
         # namespace.
         nt.assert_equal(_ip.user_ns['t'], self.fname)
 
         # Check that __file__ was not leaked back into user_ns.
         nt.assert_equal(file1, file2)
 
     def test_run_ipy_file_attribute(self):
         """Test handling of `__file__` attribute in `%run <file.ipy>`."""
         src = "t = __file__\n"
         self.mktmp(src, ext='.ipy')
         _missing = object()
         file1 = _ip.user_ns.get('__file__', _missing)
         _ip.magic('run %s' % self.fname)
         file2 = _ip.user_ns.get('__file__', _missing)
 
         # Check that __file__ was equal to the filename in the script's
         # namespace.
         nt.assert_equal(_ip.user_ns['t'], self.fname)
 
         # Check that __file__ was not leaked back into user_ns.
         nt.assert_equal(file1, file2)
 
     def test_run_formatting(self):
         """ Test that %run -t -N<N> does not raise a TypeError for N > 1."""
         src = "pass"
         self.mktmp(src)
         _ip.magic('run -t -N 1 %s' % self.fname)
         _ip.magic('run -t -N 10 %s' % self.fname)
     
     def test_ignore_sys_exit(self):
         """Test the -e option to ignore sys.exit()"""
         src = "import sys; sys.exit(1)"
         self.mktmp(src)
         with tt.AssertPrints('SystemExit'):
             _ip.magic('run %s' % self.fname)
         
         with tt.AssertNotPrints('SystemExit'):
             _ip.magic('run -e %s' % self.fname)
 
     def test_run_nb(self):
         """Test %run notebook.ipynb"""
         from nbformat import v4, writes
         nb = v4.new_notebook(
            cells=[
                 v4.new_markdown_cell("The Ultimate Question of Everything"),
                 v4.new_code_cell("answer=42")
             ]
         )
         src = writes(nb, version=4)
         self.mktmp(src, ext='.ipynb')
         
         _ip.magic("run %s" % self.fname)
         
         nt.assert_equal(_ip.user_ns['answer'], 42)
 
     def test_run_nb_error(self):
         """Test %run notebook.ipynb error"""
         from nbformat import v4, writes
         # %run when a file name isn't provided
         nt.assert_raises(Exception, _ip.magic, "run")
 
         # %run when a file doesn't exist
         nt.assert_raises(Exception, _ip.magic, "run foobar.ipynb")
 
         # %run on a notebook with an error
         nb = v4.new_notebook(
            cells=[
                 v4.new_code_cell("0/0")
             ]
         )
         src = writes(nb, version=4)
         self.mktmp(src, ext='.ipynb')
         nt.assert_raises(Exception, _ip.magic, "run %s" % self.fname)
 
     def test_file_options(self):
         src = ('import sys\n'
                'a = " ".join(sys.argv[1:])\n')
         self.mktmp(src)
         test_opts = '-x 3 --verbose'
         _ip.run_line_magic("run", '{0} {1}'.format(self.fname, test_opts))
         nt.assert_equal(_ip.user_ns['a'], test_opts)
 
 
 class TestMagicRunWithPackage(unittest.TestCase):
 
     def writefile(self, name, content):
         path = os.path.join(self.tempdir.name, name)
         d = os.path.dirname(path)
         if not os.path.isdir(d):
             os.makedirs(d)
         with open(path, 'w') as f:
             f.write(textwrap.dedent(content))
 
     def setUp(self):
         self.package = package = 'tmp{0}'.format(''.join([random.choice(string.ascii_letters) for i in range(10)]))
         """Temporary  (probably) valid python package name."""
 
         self.value = int(random.random() * 10000)
 
         self.tempdir = TemporaryDirectory()
         self.__orig_cwd = os.getcwd()
         sys.path.insert(0, self.tempdir.name)
 
         self.writefile(os.path.join(package, '__init__.py'), '')
         self.writefile(os.path.join(package, 'sub.py'), """
         x = {0!r}
         """.format(self.value))
         self.writefile(os.path.join(package, 'relative.py'), """
         from .sub import x
         """)
         self.writefile(os.path.join(package, 'absolute.py'), """
         from {0}.sub import x
         """.format(package))
         self.writefile(os.path.join(package, 'args.py'), """
         import sys
         a = " ".join(sys.argv[1:])
         """.format(package))
 
     def tearDown(self):
         os.chdir(self.__orig_cwd)
         sys.path[:] = [p for p in sys.path if p != self.tempdir.name]
         self.tempdir.cleanup()
 
     def check_run_submodule(self, submodule, opts=''):
         _ip.user_ns.pop('x', None)
         _ip.magic('run {2} -m {0}.{1}'.format(self.package, submodule, opts))
         self.assertEqual(_ip.user_ns['x'], self.value,
                          'Variable `x` is not loaded from module `{0}`.'
                          .format(submodule))
 
     def test_run_submodule_with_absolute_import(self):
         self.check_run_submodule('absolute')
 
     def test_run_submodule_with_relative_import(self):
         """Run submodule that has a relative import statement (#2727)."""
         self.check_run_submodule('relative')
 
     def test_prun_submodule_with_absolute_import(self):
         self.check_run_submodule('absolute', '-p')
 
     def test_prun_submodule_with_relative_import(self):
         self.check_run_submodule('relative', '-p')
 
     def with_fake_debugger(func):
         @functools.wraps(func)
         def wrapper(*args, **kwds):
             with patch.object(debugger.Pdb, 'run', staticmethod(eval)):
                 return func(*args, **kwds)
         return wrapper
 
     @with_fake_debugger
     def test_debug_run_submodule_with_absolute_import(self):
         self.check_run_submodule('absolute', '-d')
 
     @with_fake_debugger
     def test_debug_run_submodule_with_relative_import(self):
         self.check_run_submodule('relative', '-d')
 
     def test_module_options(self):
         _ip.user_ns.pop('a', None)
         test_opts = '-x abc -m test'
         _ip.run_line_magic('run', '-m {0}.args {1}'.format(self.package, test_opts))
         nt.assert_equal(_ip.user_ns['a'], test_opts)
 
     def test_module_options_with_separator(self):
         _ip.user_ns.pop('a', None)
         test_opts = '-x abc -m test'
         _ip.run_line_magic('run', '-m {0}.args -- {1}'.format(self.package, test_opts))
         nt.assert_equal(_ip.user_ns['a'], test_opts)
 
 def test_run__name__():
     with TemporaryDirectory() as td:
         path = pjoin(td, 'foo.py')
         with open(path, 'w') as f:
             f.write("q = __name__")
         
         _ip.user_ns.pop('q', None)
         _ip.magic('run {}'.format(path))
         nt.assert_equal(_ip.user_ns.pop('q'), '__main__')
         
         _ip.magic('run -n {}'.format(path))
         nt.assert_equal(_ip.user_ns.pop('q'), 'foo')
 
         try:
             _ip.magic('run -i -n {}'.format(path))
             nt.assert_equal(_ip.user_ns.pop('q'), 'foo')
         finally:
             _ip.magic('reset -f')
 
 
 def test_run_tb():
     """Test traceback offset in %run"""
     with TemporaryDirectory() as td:
         path = pjoin(td, 'foo.py')
         with open(path, 'w') as f:
             f.write('\n'.join([
                 "def foo():",
                 "    return bar()",
                 "def bar():",
                 "    raise RuntimeError('hello!')",
                 "foo()",
             ]))
         with capture_output() as io:
             _ip.magic('run {}'.format(path))
         out = io.stdout
         nt.assert_not_in("execfile", out)
         nt.assert_in("RuntimeError", out)
         nt.assert_equal(out.count("---->"), 3)
         del ip.user_ns['bar']
         del ip.user_ns['foo']
 
 
 def test_multiprocessing_run():
     """Set we can run mutiprocesgin without messing up up main namespace
 
     Note that import `nose.tools as nt` mdify the value s
     sys.module['__mp_main__'] so wee need to temporarily set it to None to test
     the issue.
     """
     with TemporaryDirectory() as td:
         mpm = sys.modules.get('__mp_main__')
         assert mpm is not None
         sys.modules['__mp_main__'] = None
         try:
             path = pjoin(td, 'test.py')
             with open(path, 'w') as f:
                 f.write("import multiprocessing\nprint('hoy')")
             with capture_output() as io:
                 _ip.run_line_magic('run', path)
                 _ip.run_cell("i_m_undefined")
             out = io.stdout
             nt.assert_in("hoy", out)
             nt.assert_not_in("AttributeError", out)
             nt.assert_in("NameError", out)
             nt.assert_equal(out.count("---->"), 1)
         except:
             raise
         finally:
             sys.modules['__mp_main__'] = mpm
 
 @dec.knownfailureif(sys.platform == 'win32', "writes to io.stdout aren't captured on Windows")
 def test_script_tb():
     """Test traceback offset in `ipython script.py`"""
     with TemporaryDirectory() as td:
         path = pjoin(td, 'foo.py')
         with open(path, 'w') as f:
             f.write('\n'.join([
                 "def foo():",
                 "    return bar()",
                 "def bar():",
                 "    raise RuntimeError('hello!')",
                 "foo()",
             ]))
         out, err = tt.ipexec(path)
         nt.assert_not_in("execfile", out)
         nt.assert_in("RuntimeError", out)
         nt.assert_equal(out.count("---->"), 3)
 

IPython/extensions/storemagic.py

@@ -1,233 +1,233 b''
 # -*- coding: utf-8 -*-
 """
 %store magic for lightweight persistence.
 
 Stores variables, aliases and macros in IPython's database.
 
 To automatically restore stored variables at startup, add this to your
 :file:`ipython_config.py` file::
 
   c.StoreMagics.autorestore = True
 """
 
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
 import inspect, os, sys, textwrap
 
 from IPython.core.error import UsageError
 from IPython.core.magic import Magics, magics_class, line_magic
 from traitlets import Bool
 
 
 def restore_aliases(ip, alias=None):
     staliases = ip.db.get('stored_aliases', {})
     if alias is None:
         for k,v in staliases.items():
             #print "restore alias",k,v # dbg
             #self.alias_table[k] = v
             ip.alias_manager.define_alias(k,v)
     else:
         ip.alias_manager.define_alias(alias, staliases[alias])
 
 
 def refresh_variables(ip):
     db = ip.db
     for key in db.keys('autorestore/*'):
         # strip autorestore
         justkey = os.path.basename(key)
         try:
             obj = db[key]
         except KeyError:
             print("Unable to restore variable '%s', ignoring (use %%store -d to forget!)" % justkey)
             print("The error was:", sys.exc_info()[0])
         else:
             #print "restored",justkey,"=",obj #dbg
             ip.user_ns[justkey] = obj
 
 
 def restore_dhist(ip):
     ip.user_ns['_dh'] = ip.db.get('dhist',[])
 
 
 def restore_data(ip):
     refresh_variables(ip)
     restore_aliases(ip)
     restore_dhist(ip)
 
 
 @magics_class
 class StoreMagics(Magics):
     """Lightweight persistence for python variables.
 
     Provides the %store magic."""
 
     autorestore = Bool(False, help=
         """If True, any %store-d variables will be automatically restored
         when IPython starts.
         """
     ).tag(config=True)
 
     def __init__(self, shell):
         super(StoreMagics, self).__init__(shell=shell)
         self.shell.configurables.append(self)
         if self.autorestore:
             restore_data(self.shell)
 
     @line_magic
     def store(self, parameter_s=''):
         """Lightweight persistence for python variables.
 
         Example::
 
           In [1]: l = ['hello',10,'world']
           In [2]: %store l
           In [3]: exit
 
           (IPython session is closed and started again...)
 
           ville@badger:~$ ipython
           In [1]: l
           NameError: name 'l' is not defined
           In [2]: %store -r
           In [3]: l
           Out[3]: ['hello', 10, 'world']
 
         Usage:
 
         * ``%store``          - Show list of all variables and their current
                                 values
         * ``%store spam bar`` - Store the *current* value of the variables spam
                                 and bar to disk
         * ``%store -d spam``  - Remove the variable and its value from storage
         * ``%store -z``       - Remove all variables from storage
         * ``%store -r``       - Refresh all variables, aliases and directory history
                                 from store (overwrite current vals)
         * ``%store -r spam bar`` - Refresh specified variables and aliases from store
                                    (delete current val)
         * ``%store foo >a.txt``  - Store value of foo to new file a.txt
         * ``%store foo >>a.txt`` - Append value of foo to file a.txt
 
         It should be noted that if you change the value of a variable, you
         need to %store it again if you want to persist the new value.
 
         Note also that the variables will need to be pickleable; most basic
         python types can be safely %store'd.
 
         Also aliases can be %store'd across sessions.
         To remove an alias from the storage, use the %unalias magic.
         """
 
         opts,argsl = self.parse_options(parameter_s,'drz',mode='string')
         args = argsl.split()
         ip = self.shell
         db = ip.db
         # delete
         if 'd' in opts:
             try:
                 todel = args[0]
-            except IndexError:
-                raise UsageError('You must provide the variable to forget')
+            except IndexError as e:
+                raise UsageError('You must provide the variable to forget') from e
             else:
                 try:
                     del db['autorestore/' + todel]
-                except:
-                    raise UsageError("Can't delete variable '%s'" % todel)
+                except BaseException as e:
+                    raise UsageError("Can't delete variable '%s'" % todel) from e
         # reset
         elif 'z' in opts:
             for k in db.keys('autorestore/*'):
                 del db[k]
 
         elif 'r' in opts:
             if args:
                 for arg in args:
                     try:
                         obj = db['autorestore/' + arg]
                     except KeyError:
                         try:
                             restore_aliases(ip, alias=arg)
                         except KeyError:
                             print("no stored variable or alias %s" % arg)
                     else:
                         ip.user_ns[arg] = obj
             else:
                 restore_data(ip)
 
         # run without arguments -> list variables & values
         elif not args:
             vars = db.keys('autorestore/*')
             vars.sort()
             if vars:
                 size = max(map(len, vars))
             else:
                 size = 0
 
             print('Stored variables and their in-db values:')
             fmt = '%-'+str(size)+'s -> %s'
             get = db.get
             for var in vars:
                 justkey = os.path.basename(var)
                 # print 30 first characters from every var
                 print(fmt % (justkey, repr(get(var, '<unavailable>'))[:50]))
 
         # default action - store the variable
         else:
             # %store foo >file.txt or >>file.txt
             if len(args) > 1 and args[1].startswith('>'):
                 fnam = os.path.expanduser(args[1].lstrip('>').lstrip())
                 if args[1].startswith('>>'):
                     fil = open(fnam, 'a')
                 else:
                     fil = open(fnam, 'w')
                 with fil:
                     obj = ip.ev(args[0])
                     print("Writing '%s' (%s) to file '%s'." % (args[0],
                         obj.__class__.__name__, fnam))
 
                     if not isinstance (obj, str):
                         from pprint import pprint
                         pprint(obj, fil)
                     else:
                         fil.write(obj)
                         if not obj.endswith('\n'):
                             fil.write('\n')
 
                 return
 
             # %store foo
             for arg in args:
                 try:
                     obj = ip.user_ns[arg]
                 except KeyError:
                     # it might be an alias
                     name = arg
                     try:
                         cmd = ip.alias_manager.retrieve_alias(name)
-                    except ValueError:
-                        raise UsageError("Unknown variable '%s'" % name)
+                    except ValueError as e:
+                        raise UsageError("Unknown variable '%s'" % name) from e
 
                     staliases = db.get('stored_aliases',{})
                     staliases[name] = cmd
                     db['stored_aliases'] = staliases
                     print("Alias stored: %s (%s)" % (name, cmd))
                     return
 
                 else:
                     modname = getattr(inspect.getmodule(obj), '__name__', '')
                     if modname == '__main__':
                         print(textwrap.dedent("""\
                         Warning:%s is %s
                         Proper storage of interactively declared classes (or instances
                         of those classes) is not possible! Only instances
                         of classes in real modules on file system can be %%store'd.
                         """ % (arg, obj) ))
                         return
                     #pickled = pickle.dumps(obj)
                     db[ 'autorestore/' + arg ] = obj
                     print("Stored '%s' (%s)" % (arg, obj.__class__.__name__))
 
 
 def load_ipython_extension(ip):
     """Load the extension in IPython."""
     ip.register_magics(StoreMagics)
 

IPython/lib/clipboard.py

@@ -1,69 +1,69 b''
 """ Utilities for accessing the platform's clipboard.
 """
 
 import subprocess
 
 from IPython.core.error import TryNext
 import IPython.utils.py3compat as py3compat
 
 class ClipboardEmpty(ValueError):
     pass
 
 def win32_clipboard_get():
     """ Get the current clipboard's text on Windows.
 
     Requires Mark Hammond's pywin32 extensions.
     """
     try:
         import win32clipboard
-    except ImportError:
+    except ImportError as e:
         raise TryNext("Getting text from the clipboard requires the pywin32 "
-                      "extensions: http://sourceforge.net/projects/pywin32/")
+                      "extensions: http://sourceforge.net/projects/pywin32/") from e
     win32clipboard.OpenClipboard()
     try:
         text = win32clipboard.GetClipboardData(win32clipboard.CF_UNICODETEXT)
     except (TypeError, win32clipboard.error):
         try:
             text = win32clipboard.GetClipboardData(win32clipboard.CF_TEXT)
             text = py3compat.cast_unicode(text, py3compat.DEFAULT_ENCODING)
-        except (TypeError, win32clipboard.error):
-            raise ClipboardEmpty
+        except (TypeError, win32clipboard.error) as e:
+            raise ClipboardEmpty from e
     finally:
         win32clipboard.CloseClipboard()
     return text
 
 def osx_clipboard_get() -> str:
     """ Get the clipboard's text on OS X.
     """
     p = subprocess.Popen(['pbpaste', '-Prefer', 'ascii'],
         stdout=subprocess.PIPE)
     bytes_, stderr = p.communicate()
     # Text comes in with old Mac \r line endings. Change them to \n.
     bytes_ = bytes_.replace(b'\r', b'\n')
     text = py3compat.decode(bytes_)
     return text
 
 def tkinter_clipboard_get():
     """ Get the clipboard's text using Tkinter.
 
     This is the default on systems that are not Windows or OS X. It may
     interfere with other UI toolkits and should be replaced with an
     implementation that uses that toolkit.
     """
     try:
         from tkinter import Tk, TclError 
-    except ImportError:
-        raise TryNext("Getting text from the clipboard on this platform requires tkinter.")
+    except ImportError as e:
+        raise TryNext("Getting text from the clipboard on this platform requires tkinter.") from e
         
     root = Tk()
     root.withdraw()
     try:
         text = root.clipboard_get()
-    except TclError:
-        raise ClipboardEmpty
+    except TclError as e:
+        raise ClipboardEmpty from e
     finally:
         root.destroy()
     text = py3compat.cast_unicode(text, py3compat.DEFAULT_ENCODING)
     return text
 
 

IPython/lib/deepreload.py

@@ -1,341 +1,341 b''
 # -*- coding: utf-8 -*-
 """
 Provides a reload() function that acts recursively.
 
 Python's normal :func:`python:reload` function only reloads the module that it's
 passed. The :func:`reload` function in this module also reloads everything
 imported from that module, which is useful when you're changing files deep
 inside a package.
 
 To use this as your default reload function, type this::
 
     import builtins
     from IPython.lib import deepreload
     builtins.reload = deepreload.reload
 
 A reference to the original :func:`python:reload` is stored in this module as
 :data:`original_reload`, so you can restore it later.
 
 This code is almost entirely based on knee.py, which is a Python
 re-implementation of hierarchical module import.
 """
 #*****************************************************************************
 #       Copyright (C) 2001 Nathaniel Gray <[e-mail]>
 #
 #  Distributed under the terms of the BSD License.  The full license is in
 #  the file COPYING, distributed as part of this software.
 #*****************************************************************************
 
 import builtins as builtin_mod
 from contextlib import contextmanager
 import imp
 import sys
 
 from types import ModuleType
 from warnings import warn
 import types
 
 original_import = builtin_mod.__import__
 
 @contextmanager
 def replace_import_hook(new_import):
     saved_import = builtin_mod.__import__
     builtin_mod.__import__ = new_import
     try:
         yield
     finally:
         builtin_mod.__import__ = saved_import
 
 def get_parent(globals, level):
     """
     parent, name = get_parent(globals, level)
 
     Return the package that an import is being performed in.  If globals comes
     from the module foo.bar.bat (not itself a package), this returns the
     sys.modules entry for foo.bar.  If globals is from a package's __init__.py,
     the package's entry in sys.modules is returned.
 
     If globals doesn't come from a package or a module in a package, or a
     corresponding entry is not found in sys.modules, None is returned.
     """
     orig_level = level
 
     if not level or not isinstance(globals, dict):
         return None, ''
 
     pkgname = globals.get('__package__', None)
 
     if pkgname is not None:
         # __package__ is set, so use it
         if not hasattr(pkgname, 'rindex'):
             raise ValueError('__package__ set to non-string')
         if len(pkgname) == 0:
             if level > 0:
                 raise ValueError('Attempted relative import in non-package')
             return None, ''
         name = pkgname
     else:
         # __package__ not set, so figure it out and set it
         if '__name__' not in globals:
             return None, ''
         modname = globals['__name__']
 
         if '__path__' in globals:
             # __path__ is set, so modname is already the package name
             globals['__package__'] = name = modname
         else:
             # Normal module, so work out the package name if any
             lastdot = modname.rfind('.')
             if lastdot < 0 < level:
                 raise ValueError("Attempted relative import in non-package")
             if lastdot < 0:
                 globals['__package__'] = None
                 return None, ''
             globals['__package__'] = name = modname[:lastdot]
 
     dot = len(name)
     for x in range(level, 1, -1):
         try:
             dot = name.rindex('.', 0, dot)
-        except ValueError:
+        except ValueError as e:
             raise ValueError("attempted relative import beyond top-level "
-                             "package")
+                             "package") from e
     name = name[:dot]
 
     try:
         parent = sys.modules[name]
-    except:
+    except BaseException as e:
         if orig_level < 1:
             warn("Parent module '%.200s' not found while handling absolute "
                  "import" % name)
             parent = None
         else:
             raise SystemError("Parent module '%.200s' not loaded, cannot "
-                              "perform relative import" % name)
+                              "perform relative import" % name) from e
 
     # We expect, but can't guarantee, if parent != None, that:
     # - parent.__name__ == name
     # - parent.__dict__ is globals
     # If this is violated...  Who cares?
     return parent, name
 
 def load_next(mod, altmod, name, buf):
     """
     mod, name, buf = load_next(mod, altmod, name, buf)
 
     altmod is either None or same as mod
     """
 
     if len(name) == 0:
         # completely empty module name should only happen in
         # 'from . import' (or '__import__("")')
         return mod, None, buf
 
     dot = name.find('.')
     if dot == 0:
         raise ValueError('Empty module name')
 
     if dot < 0:
         subname = name
         next = None
     else:
         subname = name[:dot]
         next = name[dot+1:]
 
     if buf != '':
         buf += '.'
     buf += subname
 
     result = import_submodule(mod, subname, buf)
     if result is None and mod != altmod:
         result = import_submodule(altmod, subname, subname)
         if result is not None:
             buf = subname
 
     if result is None:
         raise ImportError("No module named %.200s" % name)
 
     return result, next, buf
 
 
 # Need to keep track of what we've already reloaded to prevent cyclic evil
 found_now = {}
 
 def import_submodule(mod, subname, fullname):
     """m = import_submodule(mod, subname, fullname)"""
     # Require:
     # if mod == None: subname == fullname
     # else: mod.__name__ + "." + subname == fullname
 
     global found_now
     if fullname in found_now and fullname in sys.modules:
         m = sys.modules[fullname]
     else:
         print('Reloading', fullname)
         found_now[fullname] = 1
         oldm = sys.modules.get(fullname, None)
 
         if mod is None:
             path = None
         elif hasattr(mod, '__path__'):
             path = mod.__path__
         else:
             return None
 
         try:
             # This appears to be necessary on Python 3, because imp.find_module()
             # tries to import standard libraries (like io) itself, and we don't
             # want them to be processed by our deep_import_hook.
             with replace_import_hook(original_import):
                 fp, filename, stuff = imp.find_module(subname, path)
         except ImportError:
             return None
 
         try:
             m = imp.load_module(fullname, fp, filename, stuff)
         except:
             # load_module probably removed name from modules because of
             # the error.  Put back the original module object.
             if oldm:
                 sys.modules[fullname] = oldm
             raise
         finally:
             if fp: fp.close()
 
         add_submodule(mod, m, fullname, subname)
 
     return m
 
 def add_submodule(mod, submod, fullname, subname):
     """mod.{subname} = submod"""
     if mod is None:
         return #Nothing to do here.
 
     if submod is None:
         submod = sys.modules[fullname]
 
     setattr(mod, subname, submod)
 
     return
 
 def ensure_fromlist(mod, fromlist, buf, recursive):
     """Handle 'from module import a, b, c' imports."""
     if not hasattr(mod, '__path__'):
         return
     for item in fromlist:
         if not hasattr(item, 'rindex'):
             raise TypeError("Item in ``from list'' not a string")
         if item == '*':
             if recursive:
                 continue # avoid endless recursion
             try:
                 all = mod.__all__
             except AttributeError:
                 pass
             else:
                 ret = ensure_fromlist(mod, all, buf, 1)
                 if not ret:
                     return 0
         elif not hasattr(mod, item):
             import_submodule(mod, item, buf + '.' + item)
 
 def deep_import_hook(name, globals=None, locals=None, fromlist=None, level=-1):
     """Replacement for __import__()"""
     parent, buf = get_parent(globals, level)
 
     head, name, buf = load_next(parent, None if level < 0 else parent, name, buf)
 
     tail = head
     while name:
         tail, name, buf = load_next(tail, tail, name, buf)
 
     # If tail is None, both get_parent and load_next found
     # an empty module name: someone called __import__("") or
     # doctored faulty bytecode
     if tail is None:
         raise ValueError('Empty module name')
 
     if not fromlist:
         return head
 
     ensure_fromlist(tail, fromlist, buf, 0)
     return tail
 
 modules_reloading = {}
 
 def deep_reload_hook(m):
     """Replacement for reload()."""
     # Hardcode this one  as it would raise a NotImplementedError from the
     # bowels of Python and screw up the import machinery after.
     # unlike other imports the `exclude` list already in place is not enough.
 
     if m is types:
         return m
     if not isinstance(m, ModuleType):
         raise TypeError("reload() argument must be module")
 
     name = m.__name__
 
     if name not in sys.modules:
         raise ImportError("reload(): module %.200s not in sys.modules" % name)
 
     global modules_reloading
     try:
         return modules_reloading[name]
     except:
         modules_reloading[name] = m
 
     dot = name.rfind('.')
     if dot < 0:
         subname = name
         path = None
     else:
         try:
             parent = sys.modules[name[:dot]]
-        except KeyError:
+        except KeyError as e:
             modules_reloading.clear()
-            raise ImportError("reload(): parent %.200s not in sys.modules" % name[:dot])
+            raise ImportError("reload(): parent %.200s not in sys.modules" % name[:dot]) from e
         subname = name[dot+1:]
         path = getattr(parent, "__path__", None)
 
     try:
         # This appears to be necessary on Python 3, because imp.find_module()
         # tries to import standard libraries (like io) itself, and we don't
         # want them to be processed by our deep_import_hook.
         with replace_import_hook(original_import):
             fp, filename, stuff  = imp.find_module(subname, path)
     finally:
         modules_reloading.clear()
 
     try:
         newm = imp.load_module(name, fp, filename, stuff)
     except:
          # load_module probably removed name from modules because of
          # the error.  Put back the original module object.
         sys.modules[name] = m
         raise
     finally:
         if fp: fp.close()
 
     modules_reloading.clear()
     return newm
 
 # Save the original hooks
 original_reload = imp.reload
 
 # Replacement for reload()
 def reload(module, exclude=('sys', 'os.path', 'builtins', '__main__',
                             'numpy', 'numpy._globals')):
     """Recursively reload all modules used in the given module.  Optionally
     takes a list of modules to exclude from reloading.  The default exclude
     list contains sys, __main__, and __builtin__, to prevent, e.g., resetting
     display, exception, and io hooks.
     """
     global found_now
     for i in exclude:
         found_now[i] = 1
     try:
         with replace_import_hook(deep_import_hook):
             return deep_reload_hook(module)
     finally:
         found_now = {}

IPython/lib/display.py

@@ -1,651 +1,651 b''
 """Various display related classes.
 
 Authors : MinRK, gregcaporaso, dannystaple
 """
 from html import escape as html_escape
 from os.path import exists, isfile, splitext, abspath, join, isdir
 from os import walk, sep, fsdecode
 
 from IPython.core.display import DisplayObject, TextDisplayObject
 
 __all__ = ['Audio', 'IFrame', 'YouTubeVideo', 'VimeoVideo', 'ScribdDocument',
            'FileLink', 'FileLinks', 'Code']
 
 
 class Audio(DisplayObject):
     """Create an audio object.
 
     When this object is returned by an input cell or passed to the
     display function, it will result in Audio controls being displayed
     in the frontend (only works in the notebook).
 
     Parameters
     ----------
     data : numpy array, list, unicode, str or bytes
         Can be one of
 
           * Numpy 1d array containing the desired waveform (mono)
           * Numpy 2d array containing waveforms for each channel.
             Shape=(NCHAN, NSAMPLES). For the standard channel order, see
             http://msdn.microsoft.com/en-us/library/windows/hardware/dn653308(v=vs.85).aspx
           * List of float or integer representing the waveform (mono)
           * String containing the filename
           * Bytestring containing raw PCM data or
           * URL pointing to a file on the web.
 
         If the array option is used, the waveform will be normalized.
 
         If a filename or url is used, the format support will be browser
         dependent.
     url : unicode
         A URL to download the data from.
     filename : unicode
         Path to a local file to load the data from.
     embed : boolean
         Should the audio data be embedded using a data URI (True) or should
         the original source be referenced. Set this to True if you want the
         audio to playable later with no internet connection in the notebook.
 
         Default is `True`, unless the keyword argument `url` is set, then
         default value is `False`.
     rate : integer
         The sampling rate of the raw data.
         Only required when data parameter is being used as an array
     autoplay : bool
         Set to True if the audio should immediately start playing.
         Default is `False`.
     normalize : bool
         Whether audio should be normalized (rescaled) to the maximum possible
         range. Default is `True`. When set to `False`, `data` must be between
         -1 and 1 (inclusive), otherwise an error is raised.
         Applies only when `data` is a list or array of samples; other types of
         audio are never normalized.
 
     Examples
     --------
     ::
 
         # Generate a sound
         import numpy as np
         framerate = 44100
         t = np.linspace(0,5,framerate*5)
         data = np.sin(2*np.pi*220*t) + np.sin(2*np.pi*224*t)
         Audio(data,rate=framerate)
 
         # Can also do stereo or more channels
         dataleft = np.sin(2*np.pi*220*t)
         dataright = np.sin(2*np.pi*224*t)
         Audio([dataleft, dataright],rate=framerate)
 
         Audio("http://www.nch.com.au/acm/8k16bitpcm.wav")  # From URL
         Audio(url="http://www.w3schools.com/html/horse.ogg")
 
         Audio('/path/to/sound.wav')  # From file
         Audio(filename='/path/to/sound.ogg')
 
         Audio(b'RAW_WAV_DATA..)  # From bytes
         Audio(data=b'RAW_WAV_DATA..)
 
     See Also
     --------
     
     See also the ``Audio`` widgets form the ``ipywidget`` package for more flexibility and options.
     
     """
     _read_flags = 'rb'
 
     def __init__(self, data=None, filename=None, url=None, embed=None, rate=None, autoplay=False, normalize=True, *,
                  element_id=None):
         if filename is None and url is None and data is None:
             raise ValueError("No audio data found. Expecting filename, url, or data.")
         if embed is False and url is None:
             raise ValueError("No url found. Expecting url when embed=False")
 
         if url is not None and embed is not True:
             self.embed = False
         else:
             self.embed = True
         self.autoplay = autoplay
         self.element_id = element_id
         super(Audio, self).__init__(data=data, url=url, filename=filename)
 
         if self.data is not None and not isinstance(self.data, bytes):
             if rate is None:
                 raise ValueError("rate must be specified when data is a numpy array or list of audio samples.")
             self.data = Audio._make_wav(data, rate, normalize)
 
     def reload(self):
         """Reload the raw data from file or URL."""
         import mimetypes
         if self.embed:
             super(Audio, self).reload()
 
         if self.filename is not None:
             self.mimetype = mimetypes.guess_type(self.filename)[0]
         elif self.url is not None:
             self.mimetype = mimetypes.guess_type(self.url)[0]
         else:
             self.mimetype = "audio/wav"
 
     @staticmethod
     def _make_wav(data, rate, normalize):
         """ Transform a numpy array to a PCM bytestring """
         from io import BytesIO
         import wave
 
         try:
             scaled, nchan = Audio._validate_and_normalize_with_numpy(data, normalize)
         except ImportError:
             scaled, nchan = Audio._validate_and_normalize_without_numpy(data, normalize)
 
         fp = BytesIO()
         waveobj = wave.open(fp,mode='wb')
         waveobj.setnchannels(nchan)
         waveobj.setframerate(rate)
         waveobj.setsampwidth(2)
         waveobj.setcomptype('NONE','NONE')
         waveobj.writeframes(scaled)
         val = fp.getvalue()
         waveobj.close()
 
         return val
 
     @staticmethod
     def _validate_and_normalize_with_numpy(data, normalize):
         import numpy as np
 
         data = np.array(data, dtype=float)
         if len(data.shape) == 1:
             nchan = 1
         elif len(data.shape) == 2:
             # In wave files,channels are interleaved. E.g.,
             # "L1R1L2R2..." for stereo. See
             # http://msdn.microsoft.com/en-us/library/windows/hardware/dn653308(v=vs.85).aspx
             # for channel ordering
             nchan = data.shape[0]
             data = data.T.ravel()
         else:
             raise ValueError('Array audio input must be a 1D or 2D array')
         
         max_abs_value = np.max(np.abs(data))
         normalization_factor = Audio._get_normalization_factor(max_abs_value, normalize)
         scaled = data / normalization_factor * 32767
         return scaled.astype('<h').tostring(), nchan
 
 
     @staticmethod
     def _validate_and_normalize_without_numpy(data, normalize):
         import array
         import sys
 
         data = array.array('f', data)
 
         try:
             max_abs_value = float(max([abs(x) for x in data]))
-        except TypeError:
+        except TypeError as e:
             raise TypeError('Only lists of mono audio are '
-                'supported if numpy is not installed')
+                'supported if numpy is not installed') from e
 
         normalization_factor = Audio._get_normalization_factor(max_abs_value, normalize)
         scaled = array.array('h', [int(x / normalization_factor * 32767) for x in data])
         if sys.byteorder == 'big':
             scaled.byteswap()
         nchan = 1
         return scaled.tobytes(), nchan
 
     @staticmethod
     def _get_normalization_factor(max_abs_value, normalize):
         if not normalize and max_abs_value > 1:
             raise ValueError('Audio data must be between -1 and 1 when normalize=False.')
         return max_abs_value if normalize else 1
 
     def _data_and_metadata(self):
         """shortcut for returning metadata with url information, if defined"""
         md = {}
         if self.url:
             md['url'] = self.url
         if md:
             return self.data, md
         else:
             return self.data
 
     def _repr_html_(self):
         src = """
                 <audio {element_id} controls="controls" {autoplay}>
                     <source src="{src}" type="{type}" />
                     Your browser does not support the audio element.
                 </audio>
               """
         return src.format(src=self.src_attr(), type=self.mimetype, autoplay=self.autoplay_attr(),
                           element_id=self.element_id_attr())
 
     def src_attr(self):
         import base64
         if self.embed and (self.data is not None):
             data = base64=base64.b64encode(self.data).decode('ascii')
             return """data:{type};base64,{base64}""".format(type=self.mimetype,
                                                             base64=data)
         elif self.url is not None:
             return self.url
         else:
             return ""
 
     def autoplay_attr(self):
         if(self.autoplay):
             return 'autoplay="autoplay"'
         else:
             return ''
     
     def element_id_attr(self):
         if (self.element_id):
             return 'id="{element_id}"'.format(element_id=self.element_id)
         else:
             return ''
 
 class IFrame(object):
     """
     Generic class to embed an iframe in an IPython notebook
     """
 
     iframe = """
         <iframe
             width="{width}"
             height="{height}"
             src="{src}{params}"
             frameborder="0"
             allowfullscreen
         ></iframe>
         """
 
     def __init__(self, src, width, height, **kwargs):
         self.src = src
         self.width = width
         self.height = height
         self.params = kwargs
 
     def _repr_html_(self):
         """return the embed iframe"""
         if self.params:
             from urllib.parse import urlencode
             params = "?" + urlencode(self.params)
         else:
             params = ""
         return self.iframe.format(src=self.src,
                                   width=self.width,
                                   height=self.height,
                                   params=params)
 
 class YouTubeVideo(IFrame):
     """Class for embedding a YouTube Video in an IPython session, based on its video id.
 
     e.g. to embed the video from https://www.youtube.com/watch?v=foo , you would
     do::
 
         vid = YouTubeVideo("foo")
         display(vid)
 
     To start from 30 seconds::
 
         vid = YouTubeVideo("abc", start=30)
         display(vid)
 
     To calculate seconds from time as hours, minutes, seconds use
     :class:`datetime.timedelta`::
 
         start=int(timedelta(hours=1, minutes=46, seconds=40).total_seconds())
 
     Other parameters can be provided as documented at
     https://developers.google.com/youtube/player_parameters#Parameters
     
     When converting the notebook using nbconvert, a jpeg representation of the video
     will be inserted in the document.
     """
 
     def __init__(self, id, width=400, height=300, **kwargs):
         self.id=id
         src = "https://www.youtube.com/embed/{0}".format(id)
         super(YouTubeVideo, self).__init__(src, width, height, **kwargs)
     
     def _repr_jpeg_(self):
         # Deferred import
         from urllib.request import urlopen
 
         try:
             return urlopen("https://img.youtube.com/vi/{id}/hqdefault.jpg".format(id=self.id)).read()
         except IOError:
             return None
 
 class VimeoVideo(IFrame):
     """
     Class for embedding a Vimeo video in an IPython session, based on its video id.
     """
 
     def __init__(self, id, width=400, height=300, **kwargs):
         src="https://player.vimeo.com/video/{0}".format(id)
         super(VimeoVideo, self).__init__(src, width, height, **kwargs)
 
 class ScribdDocument(IFrame):
     """
     Class for embedding a Scribd document in an IPython session
 
     Use the start_page params to specify a starting point in the document
     Use the view_mode params to specify display type one off scroll | slideshow | book
 
     e.g to Display Wes' foundational paper about PANDAS in book mode from page 3
 
     ScribdDocument(71048089, width=800, height=400, start_page=3, view_mode="book")
     """
 
     def __init__(self, id, width=400, height=300, **kwargs):
         src="https://www.scribd.com/embeds/{0}/content".format(id)
         super(ScribdDocument, self).__init__(src, width, height, **kwargs)
 
 class FileLink(object):
     """Class for embedding a local file link in an IPython session, based on path
 
     e.g. to embed a link that was generated in the IPython notebook as my/data.txt
 
     you would do::
 
         local_file = FileLink("my/data.txt")
         display(local_file)
 
     or in the HTML notebook, just::
 
         FileLink("my/data.txt")
     """
 
     html_link_str = "<a href='%s' target='_blank'>%s</a>"
 
     def __init__(self,
                  path,
                  url_prefix='',
                  result_html_prefix='',
                  result_html_suffix='<br>'):
         """
         Parameters
         ----------
         path : str
             path to the file or directory that should be formatted
         url_prefix : str
             prefix to be prepended to all files to form a working link [default:
             '']
         result_html_prefix : str
             text to append to beginning to link [default: '']
         result_html_suffix : str
             text to append at the end of link [default: '<br>']
         """
         if isdir(path):
             raise ValueError("Cannot display a directory using FileLink. "
               "Use FileLinks to display '%s'." % path)
         self.path = fsdecode(path)
         self.url_prefix = url_prefix
         self.result_html_prefix = result_html_prefix
         self.result_html_suffix = result_html_suffix
 
     def _format_path(self):
         fp = ''.join([self.url_prefix, html_escape(self.path)])
         return ''.join([self.result_html_prefix,
                         self.html_link_str % \
                             (fp, html_escape(self.path, quote=False)),
                         self.result_html_suffix])
 
     def _repr_html_(self):
         """return html link to file
         """
         if not exists(self.path):
             return ("Path (<tt>%s</tt>) doesn't exist. "
                     "It may still be in the process of "
                     "being generated, or you may have the "
                     "incorrect path." % self.path)
 
         return self._format_path()
 
     def __repr__(self):
         """return absolute path to file
         """
         return abspath(self.path)
 
 class FileLinks(FileLink):
     """Class for embedding local file links in an IPython session, based on path
 
     e.g. to embed links to files that were generated in the IPython notebook
     under ``my/data``, you would do::
 
         local_files = FileLinks("my/data")
         display(local_files)
 
     or in the HTML notebook, just::
 
         FileLinks("my/data")
     """
     def __init__(self,
                  path,
                  url_prefix='',
                  included_suffixes=None,
                  result_html_prefix='',
                  result_html_suffix='<br>',
                  notebook_display_formatter=None,
                  terminal_display_formatter=None,
                  recursive=True):
         """
         See :class:`FileLink` for the ``path``, ``url_prefix``,
         ``result_html_prefix`` and ``result_html_suffix`` parameters.
 
         included_suffixes : list
           Filename suffixes to include when formatting output [default: include
           all files]
 
         notebook_display_formatter : function
           Used to format links for display in the notebook. See discussion of
           formatter functions below.
 
         terminal_display_formatter : function
           Used to format links for display in the terminal. See discussion of
           formatter functions below.
 
         Formatter functions must be of the form::
 
             f(dirname, fnames, included_suffixes)
 
         dirname : str
           The name of a directory
         fnames : list
           The files in that directory
         included_suffixes : list
           The file suffixes that should be included in the output (passing None
           meansto include all suffixes in the output in the built-in formatters)
         recursive : boolean
           Whether to recurse into subdirectories. Default is True.
 
         The function should return a list of lines that will be printed in the
         notebook (if passing notebook_display_formatter) or the terminal (if
         passing terminal_display_formatter). This function is iterated over for
         each directory in self.path. Default formatters are in place, can be
         passed here to support alternative formatting.
 
         """
         if isfile(path):
             raise ValueError("Cannot display a file using FileLinks. "
               "Use FileLink to display '%s'." % path)
         self.included_suffixes = included_suffixes
         # remove trailing slashes for more consistent output formatting
         path = path.rstrip('/')
 
         self.path = path
         self.url_prefix = url_prefix
         self.result_html_prefix = result_html_prefix
         self.result_html_suffix = result_html_suffix
 
         self.notebook_display_formatter = \
              notebook_display_formatter or self._get_notebook_display_formatter()
         self.terminal_display_formatter = \
              terminal_display_formatter or self._get_terminal_display_formatter()
 
         self.recursive = recursive
 
     def _get_display_formatter(self,
                                dirname_output_format,
                                fname_output_format,
                                fp_format,
                                fp_cleaner=None):
         """ generate built-in formatter function
 
            this is used to define both the notebook and terminal built-in
             formatters as they only differ by some wrapper text for each entry
 
            dirname_output_format: string to use for formatting directory
             names, dirname will be substituted for a single "%s" which
             must appear in this string
            fname_output_format: string to use for formatting file names,
             if a single "%s" appears in the string, fname will be substituted
             if two "%s" appear in the string, the path to fname will be
              substituted for the first and fname will be substituted for the
              second
            fp_format: string to use for formatting filepaths, must contain
             exactly two "%s" and the dirname will be substituted for the first
             and fname will be substituted for the second
         """
         def f(dirname, fnames, included_suffixes=None):
             result = []
             # begin by figuring out which filenames, if any,
             # are going to be displayed
             display_fnames = []
             for fname in fnames:
                 if (isfile(join(dirname,fname)) and
                        (included_suffixes is None or
                         splitext(fname)[1] in included_suffixes)):
                       display_fnames.append(fname)
 
             if len(display_fnames) == 0:
                 # if there are no filenames to display, don't print anything
                 # (not even the directory name)
                 pass
             else:
                 # otherwise print the formatted directory name followed by
                 # the formatted filenames
                 dirname_output_line = dirname_output_format % dirname
                 result.append(dirname_output_line)
                 for fname in display_fnames:
                     fp = fp_format % (dirname,fname)
                     if fp_cleaner is not None:
                         fp = fp_cleaner(fp)
                     try:
                         # output can include both a filepath and a filename...
                         fname_output_line = fname_output_format % (fp, fname)
                     except TypeError:
                         # ... or just a single filepath
                         fname_output_line = fname_output_format % fname
                     result.append(fname_output_line)
             return result
         return f
 
     def _get_notebook_display_formatter(self,
                                         spacer="&nbsp;&nbsp;"):
         """ generate function to use for notebook formatting
         """
         dirname_output_format = \
          self.result_html_prefix + "%s/" + self.result_html_suffix
         fname_output_format = \
          self.result_html_prefix + spacer + self.html_link_str + self.result_html_suffix
         fp_format = self.url_prefix + '%s/%s'
         if sep == "\\":
             # Working on a platform where the path separator is "\", so
             # must convert these to "/" for generating a URI
             def fp_cleaner(fp):
                 # Replace all occurrences of backslash ("\") with a forward
                 # slash ("/") - this is necessary on windows when a path is
                 # provided as input, but we must link to a URI
                 return fp.replace('\\','/')
         else:
             fp_cleaner = None
 
         return self._get_display_formatter(dirname_output_format,
                                            fname_output_format,
                                            fp_format,
                                            fp_cleaner)
 
     def _get_terminal_display_formatter(self,
                                         spacer="  "):
         """ generate function to use for terminal formatting
         """
         dirname_output_format = "%s/"
         fname_output_format = spacer + "%s"
         fp_format = '%s/%s'
 
         return self._get_display_formatter(dirname_output_format,
                                            fname_output_format,
                                            fp_format)
 
     def _format_path(self):
         result_lines = []
         if self.recursive:
             walked_dir = list(walk(self.path))
         else:
             walked_dir = [next(walk(self.path))]
         walked_dir.sort()
         for dirname, subdirs, fnames in walked_dir:
             result_lines += self.notebook_display_formatter(dirname, fnames, self.included_suffixes)
         return '\n'.join(result_lines)
 
     def __repr__(self):
         """return newline-separated absolute paths
         """
         result_lines = []
         if self.recursive:
             walked_dir = list(walk(self.path))
         else:
             walked_dir = [next(walk(self.path))]
         walked_dir.sort()
         for dirname, subdirs, fnames in walked_dir:
             result_lines += self.terminal_display_formatter(dirname, fnames, self.included_suffixes)
         return '\n'.join(result_lines)
 
 
 class Code(TextDisplayObject):
     """Display syntax-highlighted source code.
 
     This uses Pygments to highlight the code for HTML and Latex output.
 
     Parameters
     ----------
     data : str
         The code as a string
     url : str
         A URL to fetch the code from
     filename : str
         A local filename to load the code from
     language : str
         The short name of a Pygments lexer to use for highlighting.
         If not specified, it will guess the lexer based on the filename
         or the code. Available lexers: http://pygments.org/docs/lexers/
     """
     def __init__(self, data=None, url=None, filename=None, language=None):
         self.language = language
         super().__init__(data=data, url=url, filename=filename)
 
     def _get_lexer(self):
         if self.language:
             from pygments.lexers import get_lexer_by_name
             return get_lexer_by_name(self.language)
         elif self.filename:
             from pygments.lexers import get_lexer_for_filename
             return get_lexer_for_filename(self.filename)
         else:
             from pygments.lexers import guess_lexer
             return guess_lexer(self.data)
 
     def __repr__(self):
         return self.data
 
     def _repr_html_(self):
         from pygments import highlight
         from pygments.formatters import HtmlFormatter
         fmt = HtmlFormatter()
         style = '<style>{}</style>'.format(fmt.get_style_defs('.output_html'))
         return style + highlight(self.data, self._get_lexer(), fmt)
 
     def _repr_latex_(self):
         from pygments import highlight
         from pygments.formatters import LatexFormatter
         return highlight(self.data, self._get_lexer(), LatexFormatter())

IPython/lib/inputhook.py

@@ -1,663 +1,663 b''
 # coding: utf-8
 """
 Deprecated since IPython 5.0
 
 Inputhook management for GUI event loop integration.
 """
 
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
 try:
     import ctypes
 except ImportError:
     ctypes = None
 except SystemError: # IronPython issue, 2/8/2014
     ctypes = None
 import os
 import platform
 import sys
 from distutils.version import LooseVersion as V
 
 from warnings import warn
 
 
 warn("`IPython.lib.inputhook` is deprecated since IPython 5.0 and will be removed in future versions.",
         DeprecationWarning, stacklevel=2)
 
 
 #-----------------------------------------------------------------------------
 # Constants
 #-----------------------------------------------------------------------------
 
 # Constants for identifying the GUI toolkits.
 GUI_WX = 'wx'
 GUI_QT = 'qt'
 GUI_QT4 = 'qt4'
 GUI_GTK = 'gtk'
 GUI_TK = 'tk'
 GUI_OSX = 'osx'
 GUI_GLUT = 'glut'
 GUI_PYGLET = 'pyglet'
 GUI_GTK3 = 'gtk3'
 GUI_NONE = 'none' # i.e. disable
 
 #-----------------------------------------------------------------------------
 # Utilities
 #-----------------------------------------------------------------------------
 
 def _stdin_ready_posix():
     """Return True if there's something to read on stdin (posix version)."""
     infds, outfds, erfds = select.select([sys.stdin],[],[],0)
     return bool(infds)
 
 def _stdin_ready_nt():
     """Return True if there's something to read on stdin (nt version)."""
     return msvcrt.kbhit()
 
 def _stdin_ready_other():
     """Return True, assuming there's something to read on stdin."""
     return True
 
 def _use_appnope():
     """Should we use appnope for dealing with OS X app nap?
 
     Checks if we are on OS X 10.9 or greater.
     """
     return sys.platform == 'darwin' and V(platform.mac_ver()[0]) >= V('10.9')
 
 def _ignore_CTRL_C_posix():
     """Ignore CTRL+C (SIGINT)."""
     signal.signal(signal.SIGINT, signal.SIG_IGN)
 
 def _allow_CTRL_C_posix():
     """Take CTRL+C into account (SIGINT)."""
     signal.signal(signal.SIGINT, signal.default_int_handler)
 
 def _ignore_CTRL_C_other():
     """Ignore CTRL+C (not implemented)."""
     pass
 
 def _allow_CTRL_C_other():
     """Take CTRL+C into account (not implemented)."""
     pass
 
 if os.name == 'posix':
     import select
     import signal
     stdin_ready = _stdin_ready_posix
     ignore_CTRL_C = _ignore_CTRL_C_posix
     allow_CTRL_C = _allow_CTRL_C_posix
 elif os.name == 'nt':
     import msvcrt
     stdin_ready = _stdin_ready_nt
     ignore_CTRL_C = _ignore_CTRL_C_other
     allow_CTRL_C = _allow_CTRL_C_other
 else:
     stdin_ready = _stdin_ready_other
     ignore_CTRL_C = _ignore_CTRL_C_other
     allow_CTRL_C = _allow_CTRL_C_other
 
 
 #-----------------------------------------------------------------------------
 # Main InputHookManager class
 #-----------------------------------------------------------------------------
 
 
 class InputHookManager(object):
     """DEPRECATED since IPython 5.0
 
     Manage PyOS_InputHook for different GUI toolkits.
 
     This class installs various hooks under ``PyOSInputHook`` to handle
     GUI event loop integration.
     """
     
     def __init__(self):
         if ctypes is None:
             warn("IPython GUI event loop requires ctypes, %gui will not be available")
         else:
             self.PYFUNC = ctypes.PYFUNCTYPE(ctypes.c_int)
         self.guihooks = {}
         self.aliases = {}
         self.apps = {}
         self._reset()
 
     def _reset(self):
         self._callback_pyfunctype = None
         self._callback = None
         self._installed = False
         self._current_gui = None
 
     def get_pyos_inputhook(self):
         """DEPRECATED since IPython 5.0
 
         Return the current PyOS_InputHook as a ctypes.c_void_p."""
         warn("`get_pyos_inputhook` is deprecated since IPython 5.0 and will be removed in future versions.",
                 DeprecationWarning, stacklevel=2)
         return ctypes.c_void_p.in_dll(ctypes.pythonapi,"PyOS_InputHook")
 
     def get_pyos_inputhook_as_func(self):
         """DEPRECATED since IPython 5.0
 
         Return the current PyOS_InputHook as a ctypes.PYFUNCYPE."""
         warn("`get_pyos_inputhook_as_func` is deprecated since IPython 5.0 and will be removed in future versions.",
                 DeprecationWarning, stacklevel=2)
         return self.PYFUNC.in_dll(ctypes.pythonapi,"PyOS_InputHook")
 
     def set_inputhook(self, callback):
         """DEPRECATED since IPython 5.0
 
         Set PyOS_InputHook to callback and return the previous one."""
         # On platforms with 'readline' support, it's all too likely to
         # have a KeyboardInterrupt signal delivered *even before* an
         # initial ``try:`` clause in the callback can be executed, so
         # we need to disable CTRL+C in this situation.
         ignore_CTRL_C()
         self._callback = callback
         self._callback_pyfunctype = self.PYFUNC(callback)
         pyos_inputhook_ptr = self.get_pyos_inputhook()
         original = self.get_pyos_inputhook_as_func()
         pyos_inputhook_ptr.value = \
             ctypes.cast(self._callback_pyfunctype, ctypes.c_void_p).value
         self._installed = True
         return original
 
     def clear_inputhook(self, app=None):
         """DEPRECATED since IPython 5.0
 
         Set PyOS_InputHook to NULL and return the previous one.
 
         Parameters
         ----------
         app : optional, ignored
           This parameter is allowed only so that clear_inputhook() can be
           called with a similar interface as all the ``enable_*`` methods.  But
           the actual value of the parameter is ignored.  This uniform interface
           makes it easier to have user-level entry points in the main IPython
           app like :meth:`enable_gui`."""
         warn("`clear_inputhook` is deprecated since IPython 5.0 and will be removed in future versions.",
                 DeprecationWarning, stacklevel=2)
         pyos_inputhook_ptr = self.get_pyos_inputhook()
         original = self.get_pyos_inputhook_as_func()
         pyos_inputhook_ptr.value = ctypes.c_void_p(None).value
         allow_CTRL_C()
         self._reset()
         return original
 
     def clear_app_refs(self, gui=None):
         """DEPRECATED since IPython 5.0
 
         Clear IPython's internal reference to an application instance.
 
         Whenever we create an app for a user on qt4 or wx, we hold a
         reference to the app.  This is needed because in some cases bad things
         can happen if a user doesn't hold a reference themselves.  This
         method is provided to clear the references we are holding.
 
         Parameters
         ----------
         gui : None or str
             If None, clear all app references.  If ('wx', 'qt4') clear
             the app for that toolkit.  References are not held for gtk or tk
             as those toolkits don't have the notion of an app.
         """
         warn("`clear_app_refs` is deprecated since IPython 5.0 and will be removed in future versions.",
                 DeprecationWarning, stacklevel=2)
         if gui is None:
             self.apps = {}
         elif gui in self.apps:
             del self.apps[gui]
 
     def register(self, toolkitname, *aliases):
         """DEPRECATED since IPython 5.0
 
         Register a class to provide the event loop for a given GUI.
         
         This is intended to be used as a class decorator. It should be passed
         the names with which to register this GUI integration. The classes
         themselves should subclass :class:`InputHookBase`.
         
         ::
         
             @inputhook_manager.register('qt')
             class QtInputHook(InputHookBase):
                 def enable(self, app=None):
                     ...
         """
         warn("`register` is deprecated since IPython 5.0 and will be removed in future versions.",
                 DeprecationWarning, stacklevel=2)
         def decorator(cls):
             if ctypes is not None:
                 inst = cls(self)
                 self.guihooks[toolkitname] = inst
                 for a in aliases:
                     self.aliases[a] = toolkitname
             return cls
         return decorator
 
     def current_gui(self):
         """DEPRECATED since IPython 5.0
 
         Return a string indicating the currently active GUI or None."""
         warn("`current_gui` is deprecated since IPython 5.0 and will be removed in future versions.",
                 DeprecationWarning, stacklevel=2)
         return self._current_gui
 
     def enable_gui(self, gui=None, app=None):
         """DEPRECATED since IPython 5.0
 
         Switch amongst GUI input hooks by name.
 
         This is a higher level method than :meth:`set_inputhook` - it uses the
         GUI name to look up a registered object which enables the input hook
         for that GUI.
 
         Parameters
         ----------
         gui : optional, string or None
           If None (or 'none'), clears input hook, otherwise it must be one
           of the recognized GUI names (see ``GUI_*`` constants in module).
 
         app : optional, existing application object.
           For toolkits that have the concept of a global app, you can supply an
           existing one.  If not given, the toolkit will be probed for one, and if
           none is found, a new one will be created.  Note that GTK does not have
           this concept, and passing an app if ``gui=="GTK"`` will raise an error.
 
         Returns
         -------
         The output of the underlying gui switch routine, typically the actual
         PyOS_InputHook wrapper object or the GUI toolkit app created, if there was
         one.
         """
         warn("`enable_gui` is deprecated since IPython 5.0 and will be removed in future versions.",
                 DeprecationWarning, stacklevel=2)
         if gui in (None, GUI_NONE):
             return self.disable_gui()
         
         if gui in self.aliases:
             return self.enable_gui(self.aliases[gui], app)
         
         try:
             gui_hook = self.guihooks[gui]
-        except KeyError:
+        except KeyError as e:
             e = "Invalid GUI request {!r}, valid ones are: {}"
-            raise ValueError(e.format(gui, ', '.join(self.guihooks)))
+            raise ValueError(e.format(gui, ', '.join(self.guihooks))) from e
         self._current_gui = gui
 
         app = gui_hook.enable(app)
         if app is not None:
             app._in_event_loop = True
             self.apps[gui] = app
         return app
 
     def disable_gui(self):
         """DEPRECATED since IPython 5.0
 
         Disable GUI event loop integration.
         
         If an application was registered, this sets its ``_in_event_loop``
         attribute to False. It then calls :meth:`clear_inputhook`.
         """
         warn("`disable_gui` is deprecated since IPython 5.0 and will be removed in future versions.",
                 DeprecationWarning, stacklevel=2)
         gui = self._current_gui
         if gui in self.apps:
             self.apps[gui]._in_event_loop = False
         return self.clear_inputhook()
 
 class InputHookBase(object):
     """DEPRECATED since IPython 5.0
 
     Base class for input hooks for specific toolkits.
     
     Subclasses should define an :meth:`enable` method with one argument, ``app``,
     which will either be an instance of the toolkit's application class, or None.
     They may also define a :meth:`disable` method with no arguments.
     """
     def __init__(self, manager):
         self.manager = manager
 
     def disable(self):
         pass
 
 inputhook_manager = InputHookManager()
 
 @inputhook_manager.register('osx')
 class NullInputHook(InputHookBase):
     """DEPRECATED since IPython 5.0
 
     A null inputhook that doesn't need to do anything"""
     def enable(self, app=None):
         warn("This function is deprecated since IPython 5.0 and will be removed in future versions.",
                 DeprecationWarning, stacklevel=2)
 
 @inputhook_manager.register('wx')
 class WxInputHook(InputHookBase):
     def enable(self, app=None):
         """DEPRECATED since IPython 5.0
 
         Enable event loop integration with wxPython.
 
         Parameters
         ----------
         app : WX Application, optional.
             Running application to use.  If not given, we probe WX for an
             existing application object, and create a new one if none is found.
 
         Notes
         -----
         This methods sets the ``PyOS_InputHook`` for wxPython, which allows
         the wxPython to integrate with terminal based applications like
         IPython.
 
         If ``app`` is not given we probe for an existing one, and return it if
         found.  If no existing app is found, we create an :class:`wx.App` as
         follows::
 
             import wx
             app = wx.App(redirect=False, clearSigInt=False)
         """
         warn("This function is deprecated since IPython 5.0 and will be removed in future versions.",
                 DeprecationWarning, stacklevel=2)
         import wx
         
         wx_version = V(wx.__version__).version
         
         if wx_version < [2, 8]:
             raise ValueError("requires wxPython >= 2.8, but you have %s" % wx.__version__)
         
         from IPython.lib.inputhookwx import inputhook_wx
         self.manager.set_inputhook(inputhook_wx)
         if _use_appnope():
             from appnope import nope
             nope()
 
         import wx
         if app is None:
             app = wx.GetApp()
         if app is None:
             app = wx.App(redirect=False, clearSigInt=False)
 
         return app
 
     def disable(self):
         """DEPRECATED since IPython 5.0
 
         Disable event loop integration with wxPython.
 
         This restores appnapp on OS X
         """
         warn("This function is deprecated since IPython 5.0 and will be removed in future versions.",
                 DeprecationWarning, stacklevel=2)
         if _use_appnope():
             from appnope import nap
             nap()
 
 @inputhook_manager.register('qt', 'qt4')
 class Qt4InputHook(InputHookBase):
     def enable(self, app=None):
         """DEPRECATED since IPython 5.0
 
         Enable event loop integration with PyQt4.
         
         Parameters
         ----------
         app : Qt Application, optional.
             Running application to use.  If not given, we probe Qt for an
             existing application object, and create a new one if none is found.
 
         Notes
         -----
         This methods sets the PyOS_InputHook for PyQt4, which allows
         the PyQt4 to integrate with terminal based applications like
         IPython.
 
         If ``app`` is not given we probe for an existing one, and return it if
         found.  If no existing app is found, we create an :class:`QApplication`
         as follows::
 
             from PyQt4 import QtCore
             app = QtGui.QApplication(sys.argv)
         """
         warn("This function is deprecated since IPython 5.0 and will be removed in future versions.",
                 DeprecationWarning, stacklevel=2)
         from IPython.lib.inputhookqt4 import create_inputhook_qt4
         app, inputhook_qt4 = create_inputhook_qt4(self.manager, app)
         self.manager.set_inputhook(inputhook_qt4)
         if _use_appnope():
             from appnope import nope
             nope()
 
         return app
 
     def disable_qt4(self):
         """DEPRECATED since IPython 5.0
 
         Disable event loop integration with PyQt4.
 
         This restores appnapp on OS X
         """
         warn("This function is deprecated since IPython 5.0 and will be removed in future versions.",
                 DeprecationWarning, stacklevel=2)
         if _use_appnope():
             from appnope import nap
             nap()
 
 
 @inputhook_manager.register('qt5')
 class Qt5InputHook(Qt4InputHook):
     def enable(self, app=None):
         warn("This function is deprecated since IPython 5.0 and will be removed in future versions.",
                 DeprecationWarning, stacklevel=2)
         os.environ['QT_API'] = 'pyqt5'
         return Qt4InputHook.enable(self, app)
 
 
 @inputhook_manager.register('gtk')
 class GtkInputHook(InputHookBase):
     def enable(self, app=None):
         """DEPRECATED since IPython 5.0
 
         Enable event loop integration with PyGTK.
 
         Parameters
         ----------
         app : ignored
            Ignored, it's only a placeholder to keep the call signature of all
            gui activation methods consistent, which simplifies the logic of
            supporting magics.
 
         Notes
         -----
         This methods sets the PyOS_InputHook for PyGTK, which allows
         the PyGTK to integrate with terminal based applications like
         IPython.
         """
         warn("This function is deprecated since IPython 5.0 and will be removed in future versions.",
                 DeprecationWarning, stacklevel=2)
         import gtk
         try:
             gtk.set_interactive(True)
         except AttributeError:
             # For older versions of gtk, use our own ctypes version
             from IPython.lib.inputhookgtk import inputhook_gtk
             self.manager.set_inputhook(inputhook_gtk)
 
 
 @inputhook_manager.register('tk')
 class TkInputHook(InputHookBase):
     def enable(self, app=None):
         """DEPRECATED since IPython 5.0
 
         Enable event loop integration with Tk.
 
         Parameters
         ----------
         app : toplevel :class:`Tkinter.Tk` widget, optional.
             Running toplevel widget to use.  If not given, we probe Tk for an
             existing one, and create a new one if none is found.
 
         Notes
         -----
         If you have already created a :class:`Tkinter.Tk` object, the only
         thing done by this method is to register with the
         :class:`InputHookManager`, since creating that object automatically
         sets ``PyOS_InputHook``.
         """
         warn("This function is deprecated since IPython 5.0 and will be removed in future versions.",
                 DeprecationWarning, stacklevel=2)
         if app is None:
             from tkinter import Tk
             app = Tk()
             app.withdraw()
             self.manager.apps[GUI_TK] = app
             return app
 
 
 @inputhook_manager.register('glut')
 class GlutInputHook(InputHookBase):
     def enable(self, app=None):
         """DEPRECATED since IPython 5.0
 
         Enable event loop integration with GLUT.
 
         Parameters
         ----------
 
         app : ignored
             Ignored, it's only a placeholder to keep the call signature of all
             gui activation methods consistent, which simplifies the logic of
             supporting magics.
 
         Notes
         -----
 
         This methods sets the PyOS_InputHook for GLUT, which allows the GLUT to
         integrate with terminal based applications like IPython. Due to GLUT
         limitations, it is currently not possible to start the event loop
         without first creating a window. You should thus not create another
         window but use instead the created one. See 'gui-glut.py' in the
         docs/examples/lib directory.
         
         The default screen mode is set to:
         glut.GLUT_DOUBLE | glut.GLUT_RGBA | glut.GLUT_DEPTH
         """
         warn("This function is deprecated since IPython 5.0 and will be removed in future versions.",
                 DeprecationWarning, stacklevel=2)
 
         import OpenGL.GLUT as glut
         from IPython.lib.inputhookglut import glut_display_mode, \
                                               glut_close, glut_display, \
                                               glut_idle, inputhook_glut
 
         if GUI_GLUT not in self.manager.apps:
             glut.glutInit( sys.argv )
             glut.glutInitDisplayMode( glut_display_mode )
             # This is specific to freeglut
             if bool(glut.glutSetOption):
                 glut.glutSetOption( glut.GLUT_ACTION_ON_WINDOW_CLOSE,
                                     glut.GLUT_ACTION_GLUTMAINLOOP_RETURNS )
             glut.glutCreateWindow( sys.argv[0] )
             glut.glutReshapeWindow( 1, 1 )
             glut.glutHideWindow( )
             glut.glutWMCloseFunc( glut_close )
             glut.glutDisplayFunc( glut_display )
             glut.glutIdleFunc( glut_idle )
         else:
             glut.glutWMCloseFunc( glut_close )
             glut.glutDisplayFunc( glut_display )
             glut.glutIdleFunc( glut_idle)
         self.manager.set_inputhook( inputhook_glut )
 
 
     def disable(self):
         """DEPRECATED since IPython 5.0
 
         Disable event loop integration with glut.
         
         This sets PyOS_InputHook to NULL and set the display function to a
         dummy one and set the timer to a dummy timer that will be triggered
         very far in the future.
         """
         warn("This function is deprecated since IPython 5.0 and will be removed in future versions.",
                 DeprecationWarning, stacklevel=2)
         import OpenGL.GLUT as glut
         from glut_support import glutMainLoopEvent
 
         glut.glutHideWindow() # This is an event to be processed below
         glutMainLoopEvent()
         super(GlutInputHook, self).disable()
 
 @inputhook_manager.register('pyglet')
 class PygletInputHook(InputHookBase):
     def enable(self, app=None):
         """DEPRECATED since IPython 5.0
 
         Enable event loop integration with pyglet.
 
         Parameters
         ----------
         app : ignored
            Ignored, it's only a placeholder to keep the call signature of all
            gui activation methods consistent, which simplifies the logic of
            supporting magics.
 
         Notes
         -----
         This methods sets the ``PyOS_InputHook`` for pyglet, which allows
         pyglet to integrate with terminal based applications like
         IPython.
 
         """
         warn("This function is deprecated since IPython 5.0 and will be removed in future versions.",
                 DeprecationWarning, stacklevel=2)
         from IPython.lib.inputhookpyglet import inputhook_pyglet
         self.manager.set_inputhook(inputhook_pyglet)
         return app
 
 
 @inputhook_manager.register('gtk3')
 class Gtk3InputHook(InputHookBase):
     def enable(self, app=None):
         """DEPRECATED since IPython 5.0
 
         Enable event loop integration with Gtk3 (gir bindings).
 
         Parameters
         ----------
         app : ignored
            Ignored, it's only a placeholder to keep the call signature of all
            gui activation methods consistent, which simplifies the logic of
            supporting magics.
 
         Notes
         -----
         This methods sets the PyOS_InputHook for Gtk3, which allows
         the Gtk3 to integrate with terminal based applications like
         IPython.
         """
         warn("This function is deprecated since IPython 5.0 and will be removed in future versions.",
                 DeprecationWarning, stacklevel=2)
         from IPython.lib.inputhookgtk3 import inputhook_gtk3
         self.manager.set_inputhook(inputhook_gtk3)
 
 
 clear_inputhook = inputhook_manager.clear_inputhook
 set_inputhook = inputhook_manager.set_inputhook
 current_gui = inputhook_manager.current_gui
 clear_app_refs = inputhook_manager.clear_app_refs
 enable_gui = inputhook_manager.enable_gui
 disable_gui = inputhook_manager.disable_gui
 register = inputhook_manager.register
 guis = inputhook_manager.guihooks
 
 
 def _deprecated_disable():
     warn("This function is deprecated since IPython 4.0 use disable_gui() instead",
             DeprecationWarning, stacklevel=2)
     inputhook_manager.disable_gui()
     
 disable_wx = disable_qt4 = disable_gtk = disable_gtk3 = disable_glut = \
         disable_pyglet = disable_osx = _deprecated_disable

IPython/lib/inputhookglut.py

@@ -1,172 +1,172 b''
 # coding: utf-8
 """
 GLUT Inputhook support functions
 """
 
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2008-2011  The IPython Development Team
 #
 #  Distributed under the terms of the BSD License.  The full license is in
 #  the file COPYING, distributed as part of this software.
 #-----------------------------------------------------------------------------
 
 # GLUT is quite an old library and it is difficult to ensure proper
 # integration within IPython since original GLUT does not allow to handle
 # events one by one. Instead, it requires for the mainloop to be entered
 # and never returned (there is not even a function to exit he
 # mainloop). Fortunately, there are alternatives such as freeglut
 # (available for linux and windows) and the OSX implementation gives
 # access to a glutCheckLoop() function that blocks itself until a new
 # event is received. This means we have to setup the idle callback to
 # ensure we got at least one event that will unblock the function.
 #
 # Furthermore, it is not possible to install these handlers without a window
 # being first created. We choose to make this window invisible. This means that
 # display mode options are set at this level and user won't be able to change
 # them later without modifying the code. This should probably be made available
 # via IPython options system.
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 import os
 import sys
 import time
 import signal
 import OpenGL.GLUT as glut
 import OpenGL.platform as platform
 from timeit import default_timer as clock
 
 #-----------------------------------------------------------------------------
 # Constants
 #-----------------------------------------------------------------------------
 
 # Frame per second : 60
 # Should probably be an IPython option
 glut_fps = 60
 
 
 # Display mode : double buffeed + rgba + depth
 # Should probably be an IPython option
 glut_display_mode = (glut.GLUT_DOUBLE |
                      glut.GLUT_RGBA   |
                      glut.GLUT_DEPTH)
 
 glutMainLoopEvent = None
 if sys.platform == 'darwin':
     try:
         glutCheckLoop = platform.createBaseFunction(
             'glutCheckLoop', dll=platform.GLUT, resultType=None,
             argTypes=[],
             doc='glutCheckLoop(  ) -> None',
             argNames=(),
             )
-    except AttributeError:
+    except AttributeError as e:
         raise RuntimeError(
             '''Your glut implementation does not allow interactive sessions. '''
-            '''Consider installing freeglut.''')
+            '''Consider installing freeglut.''') from e
     glutMainLoopEvent = glutCheckLoop
 elif glut.HAVE_FREEGLUT:
     glutMainLoopEvent = glut.glutMainLoopEvent
 else:
     raise RuntimeError(
         '''Your glut implementation does not allow interactive sessions. '''
         '''Consider installing freeglut.''')
 
 
 #-----------------------------------------------------------------------------
 # Platform-dependent imports and functions
 #-----------------------------------------------------------------------------
 
 if os.name == 'posix':
     import select
 
     def stdin_ready():
         infds, outfds, erfds = select.select([sys.stdin],[],[],0)
         if infds:
             return True
         else:
             return False
 
 elif sys.platform == 'win32':
     import msvcrt
 
     def stdin_ready():
         return msvcrt.kbhit()
 
 #-----------------------------------------------------------------------------
 # Callback functions
 #-----------------------------------------------------------------------------
 
 def glut_display():
     # Dummy display function
     pass
 
 def glut_idle():
     # Dummy idle function
     pass
 
 def glut_close():
     # Close function only hides the current window
     glut.glutHideWindow()
     glutMainLoopEvent()
 
 def glut_int_handler(signum, frame):
     # Catch sigint and print the default message
     signal.signal(signal.SIGINT, signal.default_int_handler)
     print('\nKeyboardInterrupt')
     # Need to reprint the prompt at this stage
 
 
 
 #-----------------------------------------------------------------------------
 # Code
 #-----------------------------------------------------------------------------
 def inputhook_glut():
     """Run the pyglet event loop by processing pending events only.
 
     This keeps processing pending events until stdin is ready.  After
     processing all pending events, a call to time.sleep is inserted.  This is
     needed, otherwise, CPU usage is at 100%.  This sleep time should be tuned
     though for best performance.
     """
     # We need to protect against a user pressing Control-C when IPython is
     # idle and this is running. We trap KeyboardInterrupt and pass.
 
     signal.signal(signal.SIGINT, glut_int_handler)
 
     try:
         t = clock()
 
         # Make sure the default window is set after a window has been closed
         if glut.glutGetWindow() == 0:
             glut.glutSetWindow( 1 )
             glutMainLoopEvent()
             return 0
 
         while not stdin_ready():
             glutMainLoopEvent()
             # We need to sleep at this point to keep the idle CPU load
             # low.  However, if sleep to long, GUI response is poor.  As
             # a compromise, we watch how often GUI events are being processed
             # and switch between a short and long sleep time.  Here are some
             # stats useful in helping to tune this.
             # time    CPU load
             # 0.001   13%
             # 0.005   3%
             # 0.01    1.5%
             # 0.05    0.5%
             used_time = clock() - t
             if used_time > 10.0:
                 # print 'Sleep for 1 s'  # dbg
                 time.sleep(1.0)
             elif used_time > 0.1:
                 # Few GUI events coming in, so we can sleep longer
                 # print 'Sleep for 0.05 s'  # dbg
                 time.sleep(0.05)
             else:
                 # Many GUI events coming in, so sleep only very little
                 time.sleep(0.001)
     except KeyboardInterrupt:
         pass
     return 0

IPython/lib/latextools.py

@@ -1,220 +1,220 b''
 # -*- coding: utf-8 -*-
 """Tools for handling LaTeX."""
 
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
 from io import BytesIO, open
 import os
 import tempfile
 import shutil
 import subprocess
 from base64 import encodebytes
 import textwrap
 
 from IPython.utils.process import find_cmd, FindCmdError
 from traitlets.config import get_config
 from traitlets.config.configurable import SingletonConfigurable
 from traitlets import List, Bool, Unicode
 from IPython.utils.py3compat import cast_unicode
 
 
 class LaTeXTool(SingletonConfigurable):
     """An object to store configuration of the LaTeX tool."""
     def _config_default(self):
         return get_config()
 
     backends = List(
         Unicode(), ["matplotlib", "dvipng"],
         help="Preferred backend to draw LaTeX math equations. "
         "Backends in the list are checked one by one and the first "
         "usable one is used.  Note that `matplotlib` backend "
         "is usable only for inline style equations.  To draw  "
         "display style equations, `dvipng` backend must be specified. ",
         # It is a List instead of Enum, to make configuration more
         # flexible.  For example, to use matplotlib mainly but dvipng
         # for display style, the default ["matplotlib", "dvipng"] can
         # be used.  To NOT use dvipng so that other repr such as
         # unicode pretty printing is used, you can use ["matplotlib"].
         ).tag(config=True)
 
     use_breqn = Bool(
         True,
         help="Use breqn.sty to automatically break long equations. "
         "This configuration takes effect only for dvipng backend.",
         ).tag(config=True)
 
     packages = List(
         ['amsmath', 'amsthm', 'amssymb', 'bm'],
         help="A list of packages to use for dvipng backend. "
         "'breqn' will be automatically appended when use_breqn=True.",
         ).tag(config=True)
 
     preamble = Unicode(
         help="Additional preamble to use when generating LaTeX source "
         "for dvipng backend.",
         ).tag(config=True)
 
 
 def latex_to_png(s, encode=False, backend=None, wrap=False, color='Black',
                  scale=1.0):
     """Render a LaTeX string to PNG.
 
     Parameters
     ----------
     s : str
         The raw string containing valid inline LaTeX.
     encode : bool, optional
         Should the PNG data base64 encoded to make it JSON'able.
     backend : {matplotlib, dvipng}
         Backend for producing PNG data.
     wrap : bool
         If true, Automatically wrap `s` as a LaTeX equation.
     color : string
         Foreground color name among dvipsnames, e.g. 'Maroon' or on hex RGB
         format, e.g. '#AA20FA'.
     scale : float
         Scale factor for the resulting PNG.
 
     None is returned when the backend cannot be used.
 
     """
     s = cast_unicode(s)
     allowed_backends = LaTeXTool.instance().backends
     if backend is None:
         backend = allowed_backends[0]
     if backend not in allowed_backends:
         return None
     if backend == 'matplotlib':
         f = latex_to_png_mpl
     elif backend == 'dvipng':
         f = latex_to_png_dvipng
         if color.startswith('#'):
             # Convert hex RGB color to LaTeX RGB color.
             if len(color) == 7:
                 try:
                     color = "RGB {}".format(" ".join([str(int(x, 16)) for x in
                                                       textwrap.wrap(color[1:], 2)]))
-                except ValueError:
-                    raise ValueError('Invalid color specification {}.'.format(color))
+                except ValueError as e:
+                    raise ValueError('Invalid color specification {}.'.format(color)) from e
             else:
                 raise ValueError('Invalid color specification {}.'.format(color))
     else:
         raise ValueError('No such backend {0}'.format(backend))
     bin_data = f(s, wrap, color, scale)
     if encode and bin_data:
         bin_data = encodebytes(bin_data)
     return bin_data
 
 
 def latex_to_png_mpl(s, wrap, color='Black', scale=1.0):
     try:
         from matplotlib import mathtext
         from pyparsing import ParseFatalException
     except ImportError:
         return None
 
     # mpl mathtext doesn't support display math, force inline
     s = s.replace('$$', '$')
     if wrap:
         s = u'${0}$'.format(s)
 
     try:
         mt = mathtext.MathTextParser('bitmap')
         f = BytesIO()
         dpi = 120*scale
         mt.to_png(f, s, fontsize=12, dpi=dpi, color=color)
         return f.getvalue()
     except (ValueError, RuntimeError, ParseFatalException):
         return None
 
 
 def latex_to_png_dvipng(s, wrap, color='Black', scale=1.0):
     try:
         find_cmd('latex')
         find_cmd('dvipng')
     except FindCmdError:
         return None
     try:
         workdir = tempfile.mkdtemp()
         tmpfile = os.path.join(workdir, "tmp.tex")
         dvifile = os.path.join(workdir, "tmp.dvi")
         outfile = os.path.join(workdir, "tmp.png")
 
         with open(tmpfile, "w", encoding='utf8') as f:
             f.writelines(genelatex(s, wrap))
 
         with open(os.devnull, 'wb') as devnull:
             subprocess.check_call(
                 ["latex", "-halt-on-error", "-interaction", "batchmode", tmpfile],
                 cwd=workdir, stdout=devnull, stderr=devnull)
 
             resolution = round(150*scale)
             subprocess.check_call(
                 ["dvipng", "-T", "tight", "-D", str(resolution), "-z", "9",
                  "-bg", "transparent", "-o", outfile, dvifile, "-fg", color],
                  cwd=workdir, stdout=devnull, stderr=devnull)
 
         with open(outfile, "rb") as f:
             return f.read()
     except subprocess.CalledProcessError:
         return None
     finally:
         shutil.rmtree(workdir)
 
 
 def kpsewhich(filename):
     """Invoke kpsewhich command with an argument `filename`."""
     try:
         find_cmd("kpsewhich")
         proc = subprocess.Popen(
             ["kpsewhich", filename],
             stdout=subprocess.PIPE, stderr=subprocess.PIPE)
         (stdout, stderr) = proc.communicate()
         return stdout.strip().decode('utf8', 'replace')
     except FindCmdError:
         pass
 
 
 def genelatex(body, wrap):
     """Generate LaTeX document for dvipng backend."""
     lt = LaTeXTool.instance()
     breqn = wrap and lt.use_breqn and kpsewhich("breqn.sty")
     yield r'\documentclass{article}'
     packages = lt.packages
     if breqn:
         packages = packages + ['breqn']
     for pack in packages:
         yield r'\usepackage{{{0}}}'.format(pack)
     yield r'\pagestyle{empty}'
     if lt.preamble:
         yield lt.preamble
     yield r'\begin{document}'
     if breqn:
         yield r'\begin{dmath*}'
         yield body
         yield r'\end{dmath*}'
     elif wrap:
         yield u'$${0}$$'.format(body)
     else:
         yield body
     yield u'\\end{document}'
 
 
 _data_uri_template_png = u"""<img src="data:image/png;base64,%s" alt=%s />"""
 
 def latex_to_html(s, alt='image'):
     """Render LaTeX to HTML with embedded PNG data using data URIs.
 
     Parameters
     ----------
     s : str
         The raw string containing valid inline LateX.
     alt : str
         The alt text to use for the HTML.
     """
     base64_data = latex_to_png(s, encode=True).decode('ascii')
     if base64_data:
         return _data_uri_template_png  % (base64_data, alt)
 
 

IPython/paths.py

@@ -1,119 +1,119 b''
 """Find files and directories which IPython uses.
 """
 import os.path
 import shutil
 import tempfile
 from warnings import warn
 
 import IPython
 from IPython.utils.importstring import import_item
 from IPython.utils.path import (
     get_home_dir, get_xdg_dir, get_xdg_cache_dir, compress_user, _writable_dir,
     ensure_dir_exists, fs_encoding)
 from IPython.utils import py3compat
 
 def get_ipython_dir() -> str:
     """Get the IPython directory for this platform and user.
 
     This uses the logic in `get_home_dir` to find the home directory
     and then adds .ipython to the end of the path.
     """
 
     env = os.environ
     pjoin = os.path.join
 
 
     ipdir_def = '.ipython'
 
     home_dir = get_home_dir()
     xdg_dir = get_xdg_dir()
 
     if 'IPYTHON_DIR' in env:
         warn('The environment variable IPYTHON_DIR is deprecated since IPython 3.0. '
                 'Please use IPYTHONDIR instead.', DeprecationWarning)
     ipdir = env.get('IPYTHONDIR', env.get('IPYTHON_DIR', None))
     if ipdir is None:
         # not set explicitly, use ~/.ipython
         ipdir = pjoin(home_dir, ipdir_def)
         if xdg_dir:
             # Several IPython versions (up to 1.x) defaulted to .config/ipython
             # on Linux. We have decided to go back to using .ipython everywhere
             xdg_ipdir = pjoin(xdg_dir, 'ipython')
 
             if _writable_dir(xdg_ipdir):
                 cu = compress_user
                 if os.path.exists(ipdir):
                     warn(('Ignoring {0} in favour of {1}. Remove {0} to '
                         'get rid of this message').format(cu(xdg_ipdir), cu(ipdir)))
                 elif os.path.islink(xdg_ipdir):
                     warn(('{0} is deprecated. Move link to {1} to '
                         'get rid of this message').format(cu(xdg_ipdir), cu(ipdir)))
                 else:
                     warn('Moving {0} to {1}'.format(cu(xdg_ipdir), cu(ipdir)))
                     shutil.move(xdg_ipdir, ipdir)
 
     ipdir = os.path.normpath(os.path.expanduser(ipdir))
 
     if os.path.exists(ipdir) and not _writable_dir(ipdir):
         # ipdir exists, but is not writable
         warn("IPython dir '{0}' is not a writable location,"
                 " using a temp directory.".format(ipdir))
         ipdir = tempfile.mkdtemp()
     elif not os.path.exists(ipdir):
         parent = os.path.dirname(ipdir)
         if not _writable_dir(parent):
             # ipdir does not exist and parent isn't writable
             warn("IPython parent '{0}' is not a writable location,"
                     " using a temp directory.".format(parent))
             ipdir = tempfile.mkdtemp()
     assert isinstance(ipdir, str), "all path manipulation should be str(unicode), but are not."
     return ipdir
 
 
 def get_ipython_cache_dir() -> str:
     """Get the cache directory it is created if it does not exist."""
     xdgdir = get_xdg_cache_dir()
     if xdgdir is None:
         return get_ipython_dir()
     ipdir = os.path.join(xdgdir, "ipython")
     if not os.path.exists(ipdir) and _writable_dir(xdgdir):
         ensure_dir_exists(ipdir)
     elif not _writable_dir(xdgdir):
         return get_ipython_dir()
 
     return ipdir
 
 
 def get_ipython_package_dir() -> str:
     """Get the base directory where IPython itself is installed."""
     ipdir = os.path.dirname(IPython.__file__)
     assert isinstance(ipdir, str)
     return ipdir
 
 
 def get_ipython_module_path(module_str):
     """Find the path to an IPython module in this version of IPython.
 
     This will always find the version of the module that is in this importable
     IPython package. This will always return the path to the ``.py``
     version of the module.
     """
     if module_str == 'IPython':
         return os.path.join(get_ipython_package_dir(), '__init__.py')
     mod = import_item(module_str)
     the_path = mod.__file__.replace('.pyc', '.py')
     the_path = the_path.replace('.pyo', '.py')
     return py3compat.cast_unicode(the_path, fs_encoding)
 
 def locate_profile(profile='default'):
     """Find the path to the folder associated with a given profile.
 
     I.e. find $IPYTHONDIR/profile_whatever.
     """
     from IPython.core.profiledir import ProfileDir, ProfileDirError
     try:
         pd = ProfileDir.find_profile_dir_by_name(get_ipython_dir(), profile)
-    except ProfileDirError:
+    except ProfileDirError as e:
         # IOError makes more sense when people are expecting a path
-        raise IOError("Couldn't find profile %r" % profile)
+        raise IOError("Couldn't find profile %r" % profile) from e
     return pd.location

IPython/sphinxext/custom_doctests.py

@@ -1,155 +1,155 b''
 """
 Handlers for IPythonDirective's @doctest pseudo-decorator.
 
 The Sphinx extension that provides support for embedded IPython code provides
 a pseudo-decorator @doctest, which treats the input/output block as a
 doctest, raising a RuntimeError during doc generation if the actual output
 (after running the input) does not match the expected output.
 
 An example usage is:
 
 .. code-block:: rst
 
    .. ipython::
 
         In [1]: x = 1
 
         @doctest
         In [2]: x + 2
         Out[3]: 3
 
 One can also provide arguments to the decorator. The first argument should be
 the name of a custom handler. The specification of any other arguments is
 determined by the handler. For example,
 
 .. code-block:: rst
 
       .. ipython::
 
          @doctest float
          In [154]: 0.1 + 0.2
          Out[154]: 0.3
 
 allows the actual output ``0.30000000000000004`` to match the expected output
 due to a comparison with `np.allclose`.
 
 This module contains handlers for the @doctest pseudo-decorator. Handlers
 should have the following function signature::
 
     handler(sphinx_shell, args, input_lines, found, submitted)
 
 where `sphinx_shell` is the embedded Sphinx shell, `args` contains the list
 of arguments that follow: '@doctest handler_name', `input_lines` contains
 a list of the lines relevant to the current doctest, `found` is a string
 containing the output from the IPython shell, and `submitted` is a string
 containing the expected output from the IPython shell.
 
 Handlers must be registered in the `doctests` dict at the end of this module.
 
 """
 
 def str_to_array(s):
     """
     Simplistic converter of strings from repr to float NumPy arrays.
 
     If the repr representation has ellipsis in it, then this will fail.
 
     Parameters
     ----------
     s : str
         The repr version of a NumPy array.
 
     Examples
     --------
     >>> s = "array([ 0.3,  inf,  nan])"
     >>> a = str_to_array(s)
 
     """
     import numpy as np
 
     # Need to make sure eval() knows about inf and nan.
     # This also assumes default printoptions for NumPy.
     from numpy import inf, nan
 
     if s.startswith(u'array'):
         # Remove array( and )
         s = s[6:-1]
 
     if s.startswith(u'['):
         a = np.array(eval(s), dtype=float)
     else:
         # Assume its a regular float. Force 1D so we can index into it.
         a = np.atleast_1d(float(s))
     return a
 
 def float_doctest(sphinx_shell, args, input_lines, found, submitted):
     """
     Doctest which allow the submitted output to vary slightly from the input.
 
     Here is how it might appear in an rst file:
 
     .. code-block:: rst
 
        .. ipython::
 
           @doctest float
           In [1]: 0.1 + 0.2
           Out[1]: 0.3
 
     """
     import numpy as np
 
     if len(args) == 2:
         rtol = 1e-05
         atol = 1e-08
     else:
         # Both must be specified if any are specified.
         try:
             rtol = float(args[2])
             atol = float(args[3])
-        except IndexError:
+        except IndexError as e:
             e = ("Both `rtol` and `atol` must be specified "
                  "if either are specified: {0}".format(args))
-            raise IndexError(e)
+            raise IndexError(e) from e
 
     try:
         submitted = str_to_array(submitted)
         found = str_to_array(found)
     except:
         # For example, if the array is huge and there are ellipsis in it.
         error = True
     else:
         found_isnan = np.isnan(found)
         submitted_isnan = np.isnan(submitted)
         error = not np.allclose(found_isnan, submitted_isnan)
         error |= not np.allclose(found[~found_isnan],
                                  submitted[~submitted_isnan],
                                  rtol=rtol, atol=atol)
 
     TAB = ' ' * 4
     directive = sphinx_shell.directive
     if directive is None:
         source = 'Unavailable'
         content = 'Unavailable'
     else:
         source = directive.state.document.current_source
         # Add tabs and make into a single string.
         content = '\n'.join([TAB + line for line in directive.content])
 
     if error:
 
         e = ('doctest float comparison failure\n\n'
              'Document source: {0}\n\n'
              'Raw content: \n{1}\n\n'
              'On input line(s):\n{TAB}{2}\n\n'
              'we found output:\n{TAB}{3}\n\n'
              'instead of the expected:\n{TAB}{4}\n\n')
         e = e.format(source, content, '\n'.join(input_lines), repr(found),
                      repr(submitted), TAB=TAB)
         raise RuntimeError(e)
 
 # dict of allowable doctest handlers. The key represents the first argument
 # that must be given to @doctest in order to activate the handler.
 doctests = {
     'float': float_doctest,
 }

IPython/terminal/magics.py

@@ -1,203 +1,203 b''
 """Extra magics for terminal use."""
 
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
 
 from logging import error
 import os
 import sys
 
 from IPython.core.error import TryNext, UsageError
 from IPython.core.magic import Magics, magics_class, line_magic
 from IPython.lib.clipboard import ClipboardEmpty
 from IPython.utils.text import SList, strip_email_quotes
 from IPython.utils import py3compat
 
 def get_pasted_lines(sentinel, l_input=py3compat.input, quiet=False):
     """ Yield pasted lines until the user enters the given sentinel value.
     """
     if not quiet:
         print("Pasting code; enter '%s' alone on the line to stop or use Ctrl-D." \
               % sentinel)
         prompt = ":"
     else:
         prompt = ""
     while True:
         try:
             l = l_input(prompt)
             if l == sentinel:
                 return
             else:
                 yield l
         except EOFError:
             print('<EOF>')
             return
 
 
 @magics_class
 class TerminalMagics(Magics):
     def __init__(self, shell):
         super(TerminalMagics, self).__init__(shell)
 
     def store_or_execute(self, block, name):
         """ Execute a block, or store it in a variable, per the user's request.
         """
         if name:
             # If storing it for further editing
             self.shell.user_ns[name] = SList(block.splitlines())
             print("Block assigned to '%s'" % name)
         else:
             b = self.preclean_input(block)
             self.shell.user_ns['pasted_block'] = b
             self.shell.using_paste_magics = True
             try:
                 self.shell.run_cell(b)
             finally:
                 self.shell.using_paste_magics = False
 
     def preclean_input(self, block):
         lines = block.splitlines()
         while lines and not lines[0].strip():
             lines = lines[1:]
         return strip_email_quotes('\n'.join(lines))
 
     def rerun_pasted(self, name='pasted_block'):
         """ Rerun a previously pasted command.
         """
         b = self.shell.user_ns.get(name)
 
         # Sanity checks
         if b is None:
             raise UsageError('No previous pasted block available')
         if not isinstance(b, str):
             raise UsageError(
                 "Variable 'pasted_block' is not a string, can't execute")
 
         print("Re-executing '%s...' (%d chars)"% (b.split('\n',1)[0], len(b)))
         self.shell.run_cell(b)
 
     @line_magic
     def autoindent(self, parameter_s = ''):
         """Toggle autoindent on/off (deprecated)"""
         self.shell.set_autoindent()
         print("Automatic indentation is:",['OFF','ON'][self.shell.autoindent])
 
     @line_magic
     def cpaste(self, parameter_s=''):
         """Paste & execute a pre-formatted code block from clipboard.
 
         You must terminate the block with '--' (two minus-signs) or Ctrl-D
         alone on the line. You can also provide your own sentinel with '%paste
         -s %%' ('%%' is the new sentinel for this operation).
 
         The block is dedented prior to execution to enable execution of method
         definitions. '>' and '+' characters at the beginning of a line are
         ignored, to allow pasting directly from e-mails, diff files and
         doctests (the '...' continuation prompt is also stripped).  The
         executed block is also assigned to variable named 'pasted_block' for
         later editing with '%edit pasted_block'.
 
         You can also pass a variable name as an argument, e.g. '%cpaste foo'.
         This assigns the pasted block to variable 'foo' as string, without
         dedenting or executing it (preceding >>> and + is still stripped)
 
         '%cpaste -r' re-executes the block previously entered by cpaste.
         '%cpaste -q' suppresses any additional output messages.
 
         Do not be alarmed by garbled output on Windows (it's a readline bug).
         Just press enter and type -- (and press enter again) and the block
         will be what was just pasted.
 
         IPython statements (magics, shell escapes) are not supported (yet).
 
         See also
         --------
         paste: automatically pull code from clipboard.
 
         Examples
         --------
         ::
 
           In [8]: %cpaste
           Pasting code; enter '--' alone on the line to stop.
           :>>> a = ["world!", "Hello"]
           :>>> print " ".join(sorted(a))
           :--
           Hello world!
         """
         opts, name = self.parse_options(parameter_s, 'rqs:', mode='string')
         if 'r' in opts:
             self.rerun_pasted()
             return
 
         quiet = ('q' in opts)
 
         sentinel = opts.get('s', u'--')
         block = '\n'.join(get_pasted_lines(sentinel, quiet=quiet))
         self.store_or_execute(block, name)
 
     @line_magic
     def paste(self, parameter_s=''):
         """Paste & execute a pre-formatted code block from clipboard.
 
         The text is pulled directly from the clipboard without user
         intervention and printed back on the screen before execution (unless
         the -q flag is given to force quiet mode).
 
         The block is dedented prior to execution to enable execution of method
         definitions. '>' and '+' characters at the beginning of a line are
         ignored, to allow pasting directly from e-mails, diff files and
         doctests (the '...' continuation prompt is also stripped).  The
         executed block is also assigned to variable named 'pasted_block' for
         later editing with '%edit pasted_block'.
 
         You can also pass a variable name as an argument, e.g. '%paste foo'.
         This assigns the pasted block to variable 'foo' as string, without
         executing it (preceding >>> and + is still stripped).
 
         Options:
 
           -r: re-executes the block previously entered by cpaste.
 
           -q: quiet mode: do not echo the pasted text back to the terminal.
 
         IPython statements (magics, shell escapes) are not supported (yet).
 
         See also
         --------
         cpaste: manually paste code into terminal until you mark its end.
         """
         opts, name = self.parse_options(parameter_s, 'rq', mode='string')
         if 'r' in opts:
             self.rerun_pasted()
             return
         try:
             block = self.shell.hooks.clipboard_get()
         except TryNext as clipboard_exc:
             message = getattr(clipboard_exc, 'args')
             if message:
                 error(message[0])
             else:
                 error('Could not get text from the clipboard.')
             return
-        except ClipboardEmpty:
-            raise UsageError("The clipboard appears to be empty")
+        except ClipboardEmpty as e:
+            raise UsageError("The clipboard appears to be empty") from e
 
         # By default, echo back to terminal unless quiet mode is requested
         if 'q' not in opts:
             write = self.shell.write
             write(self.shell.pycolorize(block))
             if not block.endswith('\n'):
                 write('\n')
             write("## -- End pasted text --\n")
 
         self.store_or_execute(block, name)
 
     # Class-level: add a '%cls' magic only on Windows
     if sys.platform == 'win32':
         @line_magic
         def cls(self, s):
             """Clear screen.
             """
             os.system("cls")

IPython/terminal/pt_inputhooks/glut.py

@@ -1,140 +1,140 b''
 """GLUT Input hook for interactive use with prompt_toolkit
 """
 
 
 # GLUT is quite an old library and it is difficult to ensure proper
 # integration within IPython since original GLUT does not allow to handle
 # events one by one. Instead, it requires for the mainloop to be entered
 # and never returned (there is not even a function to exit he
 # mainloop). Fortunately, there are alternatives such as freeglut
 # (available for linux and windows) and the OSX implementation gives
 # access to a glutCheckLoop() function that blocks itself until a new
 # event is received. This means we have to setup the idle callback to
 # ensure we got at least one event that will unblock the function.
 #
 # Furthermore, it is not possible to install these handlers without a window
 # being first created. We choose to make this window invisible. This means that
 # display mode options are set at this level and user won't be able to change
 # them later without modifying the code. This should probably be made available
 # via IPython options system.
 
 import sys
 import time
 import signal
 import OpenGL.GLUT as glut
 import OpenGL.platform as platform
 from timeit import default_timer as clock
 
 # Frame per second : 60
 # Should probably be an IPython option
 glut_fps = 60
 
 # Display mode : double buffeed + rgba + depth
 # Should probably be an IPython option
 glut_display_mode = (glut.GLUT_DOUBLE |
                      glut.GLUT_RGBA   |
                      glut.GLUT_DEPTH)
 
 glutMainLoopEvent = None
 if sys.platform == 'darwin':
     try:
         glutCheckLoop = platform.createBaseFunction(
             'glutCheckLoop', dll=platform.GLUT, resultType=None,
             argTypes=[],
             doc='glutCheckLoop(  ) -> None',
             argNames=(),
             )
-    except AttributeError:
+    except AttributeError as e:
         raise RuntimeError(
             '''Your glut implementation does not allow interactive sessions. '''
-            '''Consider installing freeglut.''')
+            '''Consider installing freeglut.''') from e
     glutMainLoopEvent = glutCheckLoop
 elif glut.HAVE_FREEGLUT:
     glutMainLoopEvent = glut.glutMainLoopEvent
 else:
     raise RuntimeError(
         '''Your glut implementation does not allow interactive sessions. '''
         '''Consider installing freeglut.''')
 
 
 def glut_display():
     # Dummy display function
     pass
 
 def glut_idle():
     # Dummy idle function
     pass
 
 def glut_close():
     # Close function only hides the current window
     glut.glutHideWindow()
     glutMainLoopEvent()
 
 def glut_int_handler(signum, frame):
     # Catch sigint and print the defaultipyt   message
     signal.signal(signal.SIGINT, signal.default_int_handler)
     print('\nKeyboardInterrupt')
     # Need to reprint the prompt at this stage
 
 # Initialisation code
 glut.glutInit( sys.argv )
 glut.glutInitDisplayMode( glut_display_mode )
 # This is specific to freeglut
 if bool(glut.glutSetOption):
     glut.glutSetOption( glut.GLUT_ACTION_ON_WINDOW_CLOSE,
                         glut.GLUT_ACTION_GLUTMAINLOOP_RETURNS )
 glut.glutCreateWindow( b'ipython' )
 glut.glutReshapeWindow( 1, 1 )
 glut.glutHideWindow( )
 glut.glutWMCloseFunc( glut_close )
 glut.glutDisplayFunc( glut_display )
 glut.glutIdleFunc( glut_idle )
 
 
 def inputhook(context):
     """Run the pyglet event loop by processing pending events only.
 
     This keeps processing pending events until stdin is ready.  After
     processing all pending events, a call to time.sleep is inserted.  This is
     needed, otherwise, CPU usage is at 100%.  This sleep time should be tuned
     though for best performance.
     """
     # We need to protect against a user pressing Control-C when IPython is
     # idle and this is running. We trap KeyboardInterrupt and pass.
 
     signal.signal(signal.SIGINT, glut_int_handler)
 
     try:
         t = clock()
 
         # Make sure the default window is set after a window has been closed
         if glut.glutGetWindow() == 0:
             glut.glutSetWindow( 1 )
             glutMainLoopEvent()
             return 0
 
         while not context.input_is_ready():
             glutMainLoopEvent()
             # We need to sleep at this point to keep the idle CPU load
             # low.  However, if sleep to long, GUI response is poor.  As
             # a compromise, we watch how often GUI events are being processed
             # and switch between a short and long sleep time.  Here are some
             # stats useful in helping to tune this.
             # time    CPU load
             # 0.001   13%
             # 0.005   3%
             # 0.01    1.5%
             # 0.05    0.5%
             used_time = clock() - t
             if used_time > 10.0:
                 # print 'Sleep for 1 s'  # dbg
                 time.sleep(1.0)
             elif used_time > 0.1:
                 # Few GUI events coming in, so we can sleep longer
                 # print 'Sleep for 0.05 s'  # dbg
                 time.sleep(0.05)
             else:
                 # Many GUI events coming in, so sleep only very little
                 time.sleep(0.001)
     except KeyboardInterrupt:
         pass

IPython/testing/tools.py

@@ -1,471 +1,471 b''
 """Generic testing tools.
 
 Authors
 -------
 - Fernando Perez <[e-mail]>
 """
 
 
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
 import os
 import re
 import sys
 import tempfile
 import unittest
 
 from contextlib import contextmanager
 from io import StringIO
 from subprocess import Popen, PIPE
 from unittest.mock import patch
 
 try:
     # These tools are used by parts of the runtime, so we make the nose
     # dependency optional at this point.  Nose is a hard dependency to run the
     # test suite, but NOT to use ipython itself.
     import nose.tools as nt
     has_nose = True
 except ImportError:
     has_nose = False
 
 from traitlets.config.loader import Config
 from IPython.utils.process import get_output_error_code
 from IPython.utils.text import list_strings
 from IPython.utils.io import temp_pyfile, Tee
 from IPython.utils import py3compat
 
 from . import decorators as dec
 from . import skipdoctest
 
 
 # The docstring for full_path doctests differently on win32 (different path
 # separator) so just skip the doctest there.  The example remains informative.
 doctest_deco = skipdoctest.skip_doctest if sys.platform == 'win32' else dec.null_deco
 
 @doctest_deco
 def full_path(startPath,files):
     """Make full paths for all the listed files, based on startPath.
 
     Only the base part of startPath is kept, since this routine is typically
     used with a script's ``__file__`` variable as startPath. The base of startPath
     is then prepended to all the listed files, forming the output list.
 
     Parameters
     ----------
     startPath : string
       Initial path to use as the base for the results.  This path is split
       using os.path.split() and only its first component is kept.
 
     files : string or list
       One or more files.
 
     Examples
     --------
 
     >>> full_path('/foo/bar.py',['a.txt','b.txt'])
     ['/foo/a.txt', '/foo/b.txt']
 
     >>> full_path('/foo',['a.txt','b.txt'])
     ['/a.txt', '/b.txt']
 
     If a single file is given, the output is still a list::
 
         >>> full_path('/foo','a.txt')
         ['/a.txt']
     """
 
     files = list_strings(files)
     base = os.path.split(startPath)[0]
     return [ os.path.join(base,f) for f in files ]
 
 
 def parse_test_output(txt):
     """Parse the output of a test run and return errors, failures.
 
     Parameters
     ----------
     txt : str
       Text output of a test run, assumed to contain a line of one of the
       following forms::
 
         'FAILED (errors=1)'
         'FAILED (failures=1)'
         'FAILED (errors=1, failures=1)'
 
     Returns
     -------
     nerr, nfail
       number of errors and failures.
     """
 
     err_m = re.search(r'^FAILED \(errors=(\d+)\)', txt, re.MULTILINE)
     if err_m:
         nerr = int(err_m.group(1))
         nfail = 0
         return  nerr, nfail
 
     fail_m = re.search(r'^FAILED \(failures=(\d+)\)', txt, re.MULTILINE)
     if fail_m:
         nerr = 0
         nfail = int(fail_m.group(1))
         return  nerr, nfail
 
     both_m = re.search(r'^FAILED \(errors=(\d+), failures=(\d+)\)', txt,
                        re.MULTILINE)
     if both_m:
         nerr = int(both_m.group(1))
         nfail = int(both_m.group(2))
         return  nerr, nfail
 
     # If the input didn't match any of these forms, assume no error/failures
     return 0, 0
 
 
 # So nose doesn't think this is a test
 parse_test_output.__test__ = False
 
 
 def default_argv():
     """Return a valid default argv for creating testing instances of ipython"""
 
     return ['--quick', # so no config file is loaded
             # Other defaults to minimize side effects on stdout
             '--colors=NoColor', '--no-term-title','--no-banner',
             '--autocall=0']
 
 
 def default_config():
     """Return a config object with good defaults for testing."""
     config = Config()
     config.TerminalInteractiveShell.colors = 'NoColor'
     config.TerminalTerminalInteractiveShell.term_title = False,
     config.TerminalInteractiveShell.autocall = 0
     f = tempfile.NamedTemporaryFile(suffix=u'test_hist.sqlite', delete=False)
     config.HistoryManager.hist_file = f.name
     f.close()
     config.HistoryManager.db_cache_size = 10000
     return config
 
 
 def get_ipython_cmd(as_string=False):
     """
     Return appropriate IPython command line name. By default, this will return
     a list that can be used with subprocess.Popen, for example, but passing
     `as_string=True` allows for returning the IPython command as a string.
 
     Parameters
     ----------
     as_string: bool
         Flag to allow to return the command as a string.
     """
     ipython_cmd = [sys.executable, "-m", "IPython"]
 
     if as_string:
         ipython_cmd = " ".join(ipython_cmd)
 
     return ipython_cmd
 
 def ipexec(fname, options=None, commands=()):
     """Utility to call 'ipython filename'.
 
     Starts IPython with a minimal and safe configuration to make startup as fast
     as possible.
 
     Note that this starts IPython in a subprocess!
 
     Parameters
     ----------
     fname : str
       Name of file to be executed (should have .py or .ipy extension).
 
     options : optional, list
       Extra command-line flags to be passed to IPython.
 
     commands : optional, list
       Commands to send in on stdin
 
     Returns
     -------
     ``(stdout, stderr)`` of ipython subprocess.
     """
     if options is None: options = []
 
     cmdargs = default_argv() + options
 
     test_dir = os.path.dirname(__file__)
 
     ipython_cmd = get_ipython_cmd()
     # Absolute path for filename
     full_fname = os.path.join(test_dir, fname)
     full_cmd = ipython_cmd + cmdargs + [full_fname]
     env = os.environ.copy()
     # FIXME: ignore all warnings in ipexec while we have shims
     # should we keep suppressing warnings here, even after removing shims?
     env['PYTHONWARNINGS'] = 'ignore'
     # env.pop('PYTHONWARNINGS', None)  # Avoid extraneous warnings appearing on stderr
     for k, v in env.items():
         # Debug a bizarre failure we've seen on Windows:
         # TypeError: environment can only contain strings
         if not isinstance(v, str):
             print(k, v)
     p = Popen(full_cmd, stdout=PIPE, stderr=PIPE, stdin=PIPE, env=env)
     out, err = p.communicate(input=py3compat.encode('\n'.join(commands)) or None)
     out, err = py3compat.decode(out), py3compat.decode(err)
     # `import readline` causes 'ESC[?1034h' to be output sometimes,
     # so strip that out before doing comparisons
     if out:
         out = re.sub(r'\x1b\[[^h]+h', '', out)
     return out, err
 
 
 def ipexec_validate(fname, expected_out, expected_err='',
                     options=None, commands=()):
     """Utility to call 'ipython filename' and validate output/error.
 
     This function raises an AssertionError if the validation fails.
 
     Note that this starts IPython in a subprocess!
 
     Parameters
     ----------
     fname : str
       Name of the file to be executed (should have .py or .ipy extension).
 
     expected_out : str
       Expected stdout of the process.
 
     expected_err : optional, str
       Expected stderr of the process.
 
     options : optional, list
       Extra command-line flags to be passed to IPython.
 
     Returns
     -------
     None
     """
 
     import nose.tools as nt
 
     out, err = ipexec(fname, options, commands)
     #print 'OUT', out  # dbg
     #print 'ERR', err  # dbg
     # If there are any errors, we must check those before stdout, as they may be
     # more informative than simply having an empty stdout.
     if err:
         if expected_err:
             nt.assert_equal("\n".join(err.strip().splitlines()), "\n".join(expected_err.strip().splitlines()))
         else:
             raise ValueError('Running file %r produced error: %r' %
                              (fname, err))
     # If no errors or output on stderr was expected, match stdout
     nt.assert_equal("\n".join(out.strip().splitlines()), "\n".join(expected_out.strip().splitlines()))
 
 
 class TempFileMixin(unittest.TestCase):
     """Utility class to create temporary Python/IPython files.
 
     Meant as a mixin class for test cases."""
 
     def mktmp(self, src, ext='.py'):
         """Make a valid python temp file."""
         fname = temp_pyfile(src, ext)
         if not hasattr(self, 'tmps'):
             self.tmps=[]
         self.tmps.append(fname)
         self.fname = fname
 
     def tearDown(self):
         # If the tmpfile wasn't made because of skipped tests, like in
         # win32, there's nothing to cleanup.
         if hasattr(self, 'tmps'):
             for fname in self.tmps:
                 # If the tmpfile wasn't made because of skipped tests, like in
                 # win32, there's nothing to cleanup.
                 try:
                     os.unlink(fname)
                 except:
                     # On Windows, even though we close the file, we still can't
                     # delete it.  I have no clue why
                     pass
 
     def __enter__(self):
         return self
 
     def __exit__(self, exc_type, exc_value, traceback):
         self.tearDown()
 
 
 pair_fail_msg = ("Testing {0}\n\n"
                 "In:\n"
                 "  {1!r}\n"
                 "Expected:\n"
                 "  {2!r}\n"
                 "Got:\n"
                 "  {3!r}\n")
 def check_pairs(func, pairs):
     """Utility function for the common case of checking a function with a
     sequence of input/output pairs.
 
     Parameters
     ----------
     func : callable
       The function to be tested. Should accept a single argument.
     pairs : iterable
       A list of (input, expected_output) tuples.
 
     Returns
     -------
     None. Raises an AssertionError if any output does not match the expected
     value.
     """
     name = getattr(func, "func_name", getattr(func, "__name__", "<unknown>"))
     for inp, expected in pairs:
         out = func(inp)
         assert out == expected, pair_fail_msg.format(name, inp, expected, out)
 
 
 MyStringIO = StringIO
 
 _re_type = type(re.compile(r''))
 
 notprinted_msg = """Did not find {0!r} in printed output (on {1}):
 -------
 {2!s}
 -------
 """
 
 class AssertPrints(object):
     """Context manager for testing that code prints certain text.
 
     Examples
     --------
     >>> with AssertPrints("abc", suppress=False):
     ...     print("abcd")
     ...     print("def")
     ...
     abcd
     def
     """
     def __init__(self, s, channel='stdout', suppress=True):
         self.s = s
         if isinstance(self.s, (str, _re_type)):
             self.s = [self.s]
         self.channel = channel
         self.suppress = suppress
 
     def __enter__(self):
         self.orig_stream = getattr(sys, self.channel)
         self.buffer = MyStringIO()
         self.tee = Tee(self.buffer, channel=self.channel)
         setattr(sys, self.channel, self.buffer if self.suppress else self.tee)
 
     def __exit__(self, etype, value, traceback):
         try:
             if value is not None:
                 # If an error was raised, don't check anything else
                 return False
             self.tee.flush()
             setattr(sys, self.channel, self.orig_stream)
             printed = self.buffer.getvalue()
             for s in self.s:
                 if isinstance(s, _re_type):
                     assert s.search(printed), notprinted_msg.format(s.pattern, self.channel, printed)
                 else:
                     assert s in printed, notprinted_msg.format(s, self.channel, printed)
             return False
         finally:
             self.tee.close()
 
 printed_msg = """Found {0!r} in printed output (on {1}):
 -------
 {2!s}
 -------
 """
 
 class AssertNotPrints(AssertPrints):
     """Context manager for checking that certain output *isn't* produced.
 
     Counterpart of AssertPrints"""
     def __exit__(self, etype, value, traceback):
         try:
             if value is not None:
                 # If an error was raised, don't check anything else
                 self.tee.close()
                 return False
             self.tee.flush()
             setattr(sys, self.channel, self.orig_stream)
             printed = self.buffer.getvalue()
             for s in self.s:
                 if isinstance(s, _re_type):
                     assert not s.search(printed),printed_msg.format(
                         s.pattern, self.channel, printed)
                 else:
                     assert s not in printed, printed_msg.format(
                         s, self.channel, printed)
             return False
         finally:
             self.tee.close()
 
 @contextmanager
 def mute_warn():
     from IPython.utils import warn
     save_warn = warn.warn
     warn.warn = lambda *a, **kw: None
     try:
         yield
     finally:
         warn.warn = save_warn
 
 @contextmanager
 def make_tempfile(name):
     """ Create an empty, named, temporary file for the duration of the context.
     """
     open(name, 'w').close()
     try:
         yield
     finally:
         os.unlink(name)
 
 def fake_input(inputs):
     """Temporarily replace the input() function to return the given values
 
     Use as a context manager:
 
     with fake_input(['result1', 'result2']):
         ...
 
     Values are returned in order. If input() is called again after the last value
     was used, EOFError is raised.
     """
     it = iter(inputs)
     def mock_input(prompt=''):
         try:
             return next(it)
-        except StopIteration:
-            raise EOFError('No more inputs given')
+        except StopIteration as e:
+            raise EOFError('No more inputs given') from e
 
     return patch('builtins.input', mock_input)
 
 def help_output_test(subcommand=''):
     """test that `ipython [subcommand] -h` works"""
     cmd = get_ipython_cmd() + [subcommand, '-h']
     out, err, rc = get_output_error_code(cmd)
     nt.assert_equal(rc, 0, err)
     nt.assert_not_in("Traceback", err)
     nt.assert_in("Options", out)
     nt.assert_in("--help-all", out)
     return out, err
 
 
 def help_all_output_test(subcommand=''):
     """test that `ipython [subcommand] --help-all` works"""
     cmd = get_ipython_cmd() + [subcommand, '--help-all']
     out, err, rc = get_output_error_code(cmd)
     nt.assert_equal(rc, 0, err)
     nt.assert_not_in("Traceback", err)
     nt.assert_in("Options", out)
     nt.assert_in("Class", out)
     return out, err
 

IPython/utils/_process_win32.py

@@ -1,205 +1,205 b''
 """Windows-specific implementation of process utilities.
 
 This file is only meant to be imported by process.py, not by end-users.
 """
 
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2010-2011  The IPython Development Team
 #
 #  Distributed under the terms of the BSD License.  The full license is in
 #  the file COPYING, distributed as part of this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 
 # stdlib
 import os
 import sys
 import ctypes
 import time
 
 from ctypes import c_int, POINTER
 from ctypes.wintypes import LPCWSTR, HLOCAL
 from subprocess import STDOUT, TimeoutExpired
 from threading import Thread
 
 # our own imports
 from ._process_common import read_no_interrupt, process_handler, arg_split as py_arg_split
 from . import py3compat
 from .encoding import DEFAULT_ENCODING
 
 #-----------------------------------------------------------------------------
 # Function definitions
 #-----------------------------------------------------------------------------
 
 class AvoidUNCPath(object):
     """A context manager to protect command execution from UNC paths.
 
     In the Win32 API, commands can't be invoked with the cwd being a UNC path.
     This context manager temporarily changes directory to the 'C:' drive on
     entering, and restores the original working directory on exit.
 
     The context manager returns the starting working directory *if* it made a
     change and None otherwise, so that users can apply the necessary adjustment
     to their system calls in the event of a change.
 
     Examples
     --------
     ::
         cmd = 'dir'
         with AvoidUNCPath() as path:
             if path is not None:
                 cmd = '"pushd %s &&"%s' % (path, cmd)
             os.system(cmd)
     """
     def __enter__(self):
         self.path = os.getcwd()
         self.is_unc_path = self.path.startswith(r"\\")
         if self.is_unc_path:
             # change to c drive (as cmd.exe cannot handle UNC addresses)
             os.chdir("C:")
             return self.path
         else:
             # We return None to signal that there was no change in the working
             # directory
             return None
 
     def __exit__(self, exc_type, exc_value, traceback):
         if self.is_unc_path:
             os.chdir(self.path)
 
 
 def _find_cmd(cmd):
     """Find the full path to a .bat or .exe using the win32api module."""
     try:
         from win32api import SearchPath
-    except ImportError:
-        raise ImportError('you need to have pywin32 installed for this to work')
+    except ImportError as e:
+        raise ImportError('you need to have pywin32 installed for this to work') from e
     else:
         PATH = os.environ['PATH']
         extensions = ['.exe', '.com', '.bat', '.py']
         path = None
         for ext in extensions:
             try:
                 path = SearchPath(PATH, cmd, ext)[0]
             except:
                 pass
         if path is None:
             raise OSError("command %r not found" % cmd)
         else:
             return path
 
 
 def _system_body(p):
     """Callback for _system."""
     enc = DEFAULT_ENCODING
 
     def stdout_read():
         for line in read_no_interrupt(p.stdout).splitlines():
             line = line.decode(enc, 'replace')
             print(line, file=sys.stdout)
 
     def stderr_read():
         for line in read_no_interrupt(p.stderr).splitlines():
             line = line.decode(enc, 'replace')
             print(line, file=sys.stderr)
 
     Thread(target=stdout_read).start()
     Thread(target=stderr_read).start()
 
     # Wait to finish for returncode. Unfortunately, Python has a bug where
     # wait() isn't interruptible (https://bugs.python.org/issue28168) so poll in
     # a loop instead of just doing `return p.wait()`.
     while True:
         result = p.poll()
         if result is None:
             time.sleep(0.01)
         else:
             return result
 
 
 def system(cmd):
     """Win32 version of os.system() that works with network shares.
 
     Note that this implementation returns None, as meant for use in IPython.
 
     Parameters
     ----------
     cmd : str or list
       A command to be executed in the system shell.
 
     Returns
     -------
     int : child process' exit code.
     """
     # The controller provides interactivity with both
     # stdin and stdout
     #import _process_win32_controller
     #_process_win32_controller.system(cmd)
 
     with AvoidUNCPath() as path:
         if path is not None:
             cmd = '"pushd %s &&"%s' % (path, cmd)
         return process_handler(cmd, _system_body)
 
 def getoutput(cmd):
     """Return standard output of executing cmd in a shell.
 
     Accepts the same arguments as os.system().
 
     Parameters
     ----------
     cmd : str or list
       A command to be executed in the system shell.
 
     Returns
     -------
     stdout : str
     """
 
     with AvoidUNCPath() as path:
         if path is not None:
             cmd = '"pushd %s &&"%s' % (path, cmd)
         out = process_handler(cmd, lambda p: p.communicate()[0], STDOUT)
 
     if out is None:
         out = b''
     return py3compat.decode(out)
 
 try:
     CommandLineToArgvW = ctypes.windll.shell32.CommandLineToArgvW
     CommandLineToArgvW.arg_types = [LPCWSTR, POINTER(c_int)]
     CommandLineToArgvW.restype = POINTER(LPCWSTR)
     LocalFree = ctypes.windll.kernel32.LocalFree
     LocalFree.res_type = HLOCAL
     LocalFree.arg_types = [HLOCAL]
     
     def arg_split(commandline, posix=False, strict=True):
         """Split a command line's arguments in a shell-like manner.
 
         This is a special version for windows that use a ctypes call to CommandLineToArgvW
         to do the argv splitting. The posix parameter is ignored.
         
         If strict=False, process_common.arg_split(...strict=False) is used instead.
         """
         #CommandLineToArgvW returns path to executable if called with empty string.
         if commandline.strip() == "":
             return []
         if not strict:
             # not really a cl-arg, fallback on _process_common
             return py_arg_split(commandline, posix=posix, strict=strict)
         argvn = c_int()
         result_pointer = CommandLineToArgvW(py3compat.cast_unicode(commandline.lstrip()), ctypes.byref(argvn))
         result_array_type = LPCWSTR * argvn.value
         result = [arg for arg in result_array_type.from_address(ctypes.addressof(result_pointer.contents))]
         retval = LocalFree(result_pointer)
         return result
 except AttributeError:
     arg_split = py_arg_split
 
 def check_pid(pid):
     # OpenProcess returns 0 if no such process (of ours) exists
     # positive int otherwise
     return bool(ctypes.windll.kernel32.OpenProcess(1,0,pid))

IPython/utils/coloransi.py

@@ -1,187 +1,187 b''
 # -*- coding: utf-8 -*-
 """Tools for coloring text in ANSI terminals.
 """
 
 #*****************************************************************************
 #       Copyright (C) 2002-2006 Fernando Perez. <[e-mail]>
 #
 #  Distributed under the terms of the BSD License.  The full license is in
 #  the file COPYING, distributed as part of this software.
 #*****************************************************************************
 
 __all__ = ['TermColors','InputTermColors','ColorScheme','ColorSchemeTable']
 
 import os
 
 from IPython.utils.ipstruct import Struct
 
 color_templates = (
         # Dark colors
         ("Black"       , "0;30"),
         ("Red"         , "0;31"),
         ("Green"       , "0;32"),
         ("Brown"       , "0;33"),
         ("Blue"        , "0;34"),
         ("Purple"      , "0;35"),
         ("Cyan"        , "0;36"),
         ("LightGray"   , "0;37"),
         # Light colors
         ("DarkGray"    , "1;30"),
         ("LightRed"    , "1;31"),
         ("LightGreen"  , "1;32"),
         ("Yellow"      , "1;33"),
         ("LightBlue"   , "1;34"),
         ("LightPurple" , "1;35"),
         ("LightCyan"   , "1;36"),
         ("White"       , "1;37"),
         # Blinking colors.  Probably should not be used in anything serious.
         ("BlinkBlack"  , "5;30"),
         ("BlinkRed"    , "5;31"),
         ("BlinkGreen"  , "5;32"),
         ("BlinkYellow" , "5;33"),
         ("BlinkBlue"   , "5;34"),
         ("BlinkPurple" , "5;35"),
         ("BlinkCyan"   , "5;36"),
         ("BlinkLightGray", "5;37"),
         )
 
 def make_color_table(in_class):
     """Build a set of color attributes in a class.
 
     Helper function for building the :class:`TermColors` and
     :class`InputTermColors`.
     """
     for name,value in color_templates:
         setattr(in_class,name,in_class._base % value)
 
 class TermColors:
     """Color escape sequences.
 
     This class defines the escape sequences for all the standard (ANSI?)
     colors in terminals. Also defines a NoColor escape which is just the null
     string, suitable for defining 'dummy' color schemes in terminals which get
     confused by color escapes.
 
     This class should be used as a mixin for building color schemes."""
 
     NoColor = ''  # for color schemes in color-less terminals.
     Normal = '\033[0m'   # Reset normal coloring
     _base  = '\033[%sm'  # Template for all other colors
 
 # Build the actual color table as a set of class attributes:
 make_color_table(TermColors)
 
 class InputTermColors:
     """Color escape sequences for input prompts.
 
     This class is similar to TermColors, but the escapes are wrapped in \001
     and \002 so that readline can properly know the length of each line and
     can wrap lines accordingly.  Use this class for any colored text which
     needs to be used in input prompts, such as in calls to raw_input().
 
     This class defines the escape sequences for all the standard (ANSI?)
     colors in terminals. Also defines a NoColor escape which is just the null
     string, suitable for defining 'dummy' color schemes in terminals which get
     confused by color escapes.
 
     This class should be used as a mixin for building color schemes."""
 
     NoColor = ''  # for color schemes in color-less terminals.
 
     if os.name == 'nt' and os.environ.get('TERM','dumb') == 'emacs':
         # (X)emacs on W32 gets confused with \001 and \002 so we remove them
         Normal = '\033[0m'   # Reset normal coloring
         _base  = '\033[%sm'  # Template for all other colors
     else:
         Normal = '\001\033[0m\002'   # Reset normal coloring
         _base  = '\001\033[%sm\002'  # Template for all other colors
 
 # Build the actual color table as a set of class attributes:
 make_color_table(InputTermColors)
 
 class NoColors:
     """This defines all the same names as the colour classes, but maps them to
     empty strings, so it can easily be substituted to turn off colours."""
     NoColor = ''
     Normal  = ''
 
 for name, value in color_templates:
     setattr(NoColors, name, '')
 
 class ColorScheme:
     """Generic color scheme class. Just a name and a Struct."""
     def __init__(self,__scheme_name_,colordict=None,**colormap):
         self.name = __scheme_name_
         if colordict is None:
             self.colors = Struct(**colormap)
         else:
             self.colors = Struct(colordict)
 
     def copy(self,name=None):
         """Return a full copy of the object, optionally renaming it."""
         if name is None:
             name = self.name
         return ColorScheme(name, self.colors.dict())
 
 class ColorSchemeTable(dict):
     """General class to handle tables of color schemes.
 
     It's basically a dict of color schemes with a couple of shorthand
     attributes and some convenient methods.
 
     active_scheme_name -> obvious
     active_colors -> actual color table of the active scheme"""
 
     def __init__(self, scheme_list=None, default_scheme=''):
         """Create a table of color schemes.
 
         The table can be created empty and manually filled or it can be
         created with a list of valid color schemes AND the specification for
         the default active scheme.
         """
 
         # create object attributes to be set later
         self.active_scheme_name = ''
         self.active_colors = None
 
         if scheme_list:
             if default_scheme == '':
                 raise ValueError('you must specify the default color scheme')
             for scheme in scheme_list:
                 self.add_scheme(scheme)
             self.set_active_scheme(default_scheme)
 
     def copy(self):
         """Return full copy of object"""
         return ColorSchemeTable(self.values(),self.active_scheme_name)
 
     def add_scheme(self,new_scheme):
         """Add a new color scheme to the table."""
         if not isinstance(new_scheme,ColorScheme):
             raise ValueError('ColorSchemeTable only accepts ColorScheme instances')
         self[new_scheme.name] = new_scheme
 
     def set_active_scheme(self,scheme,case_sensitive=0):
         """Set the currently active scheme.
 
         Names are by default compared in a case-insensitive way, but this can
         be changed by setting the parameter case_sensitive to true."""
 
         scheme_names = list(self.keys())
         if case_sensitive:
             valid_schemes = scheme_names
             scheme_test = scheme
         else:
             valid_schemes = [s.lower() for s in scheme_names]
             scheme_test = scheme.lower()
         try:
             scheme_idx = valid_schemes.index(scheme_test)
-        except ValueError:
+        except ValueError as e:
             raise ValueError('Unrecognized color scheme: ' + scheme + \
-                  '\nValid schemes: '+str(scheme_names).replace("'', ",''))
+                  '\nValid schemes: '+str(scheme_names).replace("'', ",'')) from e
         else:
             active = scheme_names[scheme_idx]
             self.active_scheme_name = active
             self.active_colors = self[active].colors
             # Now allow using '' as an index for the current active scheme
             self[''] = self[active]

IPython/utils/importstring.py

@@ -1,39 +1,39 b''
 # encoding: utf-8
 """
 A simple utility to import something by its string name.
 """
 
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
 
 def import_item(name):
     """Import and return ``bar`` given the string ``foo.bar``.
 
     Calling ``bar = import_item("foo.bar")`` is the functional equivalent of
     executing the code ``from foo import bar``.
 
     Parameters
     ----------
     name : string
       The fully qualified name of the module/package being imported.
 
     Returns
     -------
     mod : module object
        The module that was imported.
     """
     
     parts = name.rsplit('.', 1)
     if len(parts) == 2:
         # called with 'foo.bar....'
         package, obj = parts
         module = __import__(package, fromlist=[obj])
         try:
             pak = getattr(module, obj)
-        except AttributeError:
-            raise ImportError('No module named %s' % obj)
+        except AttributeError as e:
+            raise ImportError('No module named %s' % obj) from e
         return pak
     else:
         # called with un-dotted string
         return __import__(parts[0])

IPython/utils/ipstruct.py

@@ -1,391 +1,391 b''
 # encoding: utf-8
 """A dict subclass that supports attribute style access.
 
 Authors:
 
 * Fernando Perez (original)
 * Brian Granger (refactoring to a dict subclass)
 """
 
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2008-2011  The IPython Development Team
 #
 #  Distributed under the terms of the BSD License.  The full license is in
 #  the file COPYING, distributed as part of this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 
 __all__ = ['Struct']
 
 #-----------------------------------------------------------------------------
 # Code
 #-----------------------------------------------------------------------------
 
 
 class Struct(dict):
     """A dict subclass with attribute style access.
 
     This dict subclass has a a few extra features:
 
     * Attribute style access.
     * Protection of class members (like keys, items) when using attribute
       style access.
     * The ability to restrict assignment to only existing keys.
     * Intelligent merging.
     * Overloaded operators.
     """
     _allownew = True
     def __init__(self, *args, **kw):
         """Initialize with a dictionary, another Struct, or data.
 
         Parameters
         ----------
         args : dict, Struct
             Initialize with one dict or Struct
         kw : dict
             Initialize with key, value pairs.
 
         Examples
         --------
 
         >>> s = Struct(a=10,b=30)
         >>> s.a
         10
         >>> s.b
         30
         >>> s2 = Struct(s,c=30)
         >>> sorted(s2.keys())
         ['a', 'b', 'c']
         """
         object.__setattr__(self, '_allownew', True)
         dict.__init__(self, *args, **kw)
 
     def __setitem__(self, key, value):
         """Set an item with check for allownew.
 
         Examples
         --------
 
         >>> s = Struct()
         >>> s['a'] = 10
         >>> s.allow_new_attr(False)
         >>> s['a'] = 10
         >>> s['a']
         10
         >>> try:
         ...     s['b'] = 20
         ... except KeyError:
         ...     print('this is not allowed')
         ...
         this is not allowed
         """
         if not self._allownew and key not in self:
             raise KeyError(
                 "can't create new attribute %s when allow_new_attr(False)" % key)
         dict.__setitem__(self, key, value)
 
     def __setattr__(self, key, value):
         """Set an attr with protection of class members.
 
         This calls :meth:`self.__setitem__` but convert :exc:`KeyError` to
         :exc:`AttributeError`.
 
         Examples
         --------
 
         >>> s = Struct()
         >>> s.a = 10
         >>> s.a
         10
         >>> try:
         ...     s.get = 10
         ... except AttributeError:
         ...     print("you can't set a class member")
         ...
         you can't set a class member
         """
         # If key is an str it might be a class member or instance var
         if isinstance(key, str):
             # I can't simply call hasattr here because it calls getattr, which
             # calls self.__getattr__, which returns True for keys in
             # self._data.  But I only want keys in the class and in
             # self.__dict__
             if key in self.__dict__ or hasattr(Struct, key):
                 raise AttributeError(
                     'attr %s is a protected member of class Struct.' % key
                 )
         try:
             self.__setitem__(key, value)
         except KeyError as e:
-            raise AttributeError(e)
+            raise AttributeError(e) from e
 
     def __getattr__(self, key):
         """Get an attr by calling :meth:`dict.__getitem__`.
 
         Like :meth:`__setattr__`, this method converts :exc:`KeyError` to
         :exc:`AttributeError`.
 
         Examples
         --------
 
         >>> s = Struct(a=10)
         >>> s.a
         10
         >>> type(s.get)
         <... 'builtin_function_or_method'>
         >>> try:
         ...     s.b
         ... except AttributeError:
         ...     print("I don't have that key")
         ...
         I don't have that key
         """
         try:
             result = self[key]
-        except KeyError:
-            raise AttributeError(key)
+        except KeyError as e:
+            raise AttributeError(key) from e
         else:
             return result
 
     def __iadd__(self, other):
         """s += s2 is a shorthand for s.merge(s2).
 
         Examples
         --------
 
         >>> s = Struct(a=10,b=30)
         >>> s2 = Struct(a=20,c=40)
         >>> s += s2
         >>> sorted(s.keys())
         ['a', 'b', 'c']
         """
         self.merge(other)
         return self
 
     def __add__(self,other):
         """s + s2 -> New Struct made from s.merge(s2).
 
         Examples
         --------
 
         >>> s1 = Struct(a=10,b=30)
         >>> s2 = Struct(a=20,c=40)
         >>> s = s1 + s2
         >>> sorted(s.keys())
         ['a', 'b', 'c']
         """
         sout = self.copy()
         sout.merge(other)
         return sout
 
     def __sub__(self,other):
         """s1 - s2 -> remove keys in s2 from s1.
 
         Examples
         --------
 
         >>> s1 = Struct(a=10,b=30)
         >>> s2 = Struct(a=40)
         >>> s = s1 - s2
         >>> s
         {'b': 30}
         """
         sout = self.copy()
         sout -= other
         return sout
 
     def __isub__(self,other):
         """Inplace remove keys from self that are in other.
 
         Examples
         --------
 
         >>> s1 = Struct(a=10,b=30)
         >>> s2 = Struct(a=40)
         >>> s1 -= s2
         >>> s1
         {'b': 30}
         """
         for k in other.keys():
             if k in self:
                 del self[k]
         return self
 
     def __dict_invert(self, data):
         """Helper function for merge.
 
         Takes a dictionary whose values are lists and returns a dict with
         the elements of each list as keys and the original keys as values.
         """
         outdict = {}
         for k,lst in data.items():
             if isinstance(lst, str):
                 lst = lst.split()
             for entry in lst:
                 outdict[entry] = k
         return outdict
 
     def dict(self):
         return self
 
     def copy(self):
         """Return a copy as a Struct.
 
         Examples
         --------
 
         >>> s = Struct(a=10,b=30)
         >>> s2 = s.copy()
         >>> type(s2) is Struct
         True
         """
         return Struct(dict.copy(self))
 
     def hasattr(self, key):
         """hasattr function available as a method.
 
         Implemented like has_key.
 
         Examples
         --------
 
         >>> s = Struct(a=10)
         >>> s.hasattr('a')
         True
         >>> s.hasattr('b')
         False
         >>> s.hasattr('get')
         False
         """
         return key in self
 
     def allow_new_attr(self, allow = True):
         """Set whether new attributes can be created in this Struct.
 
         This can be used to catch typos by verifying that the attribute user
         tries to change already exists in this Struct.
         """
         object.__setattr__(self, '_allownew', allow)
 
     def merge(self, __loc_data__=None, __conflict_solve=None, **kw):
         """Merge two Structs with customizable conflict resolution.
 
         This is similar to :meth:`update`, but much more flexible. First, a
         dict is made from data+key=value pairs. When merging this dict with
         the Struct S, the optional dictionary 'conflict' is used to decide
         what to do.
 
         If conflict is not given, the default behavior is to preserve any keys
         with their current value (the opposite of the :meth:`update` method's
         behavior).
 
         Parameters
         ----------
         __loc_data : dict, Struct
             The data to merge into self
         __conflict_solve : dict
             The conflict policy dict.  The keys are binary functions used to
             resolve the conflict and the values are lists of strings naming
             the keys the conflict resolution function applies to.  Instead of
             a list of strings a space separated string can be used, like
             'a b c'.
         kw : dict
             Additional key, value pairs to merge in
 
         Notes
         -----
 
         The `__conflict_solve` dict is a dictionary of binary functions which will be used to
         solve key conflicts.  Here is an example::
 
             __conflict_solve = dict(
                 func1=['a','b','c'],
                 func2=['d','e']
             )
 
         In this case, the function :func:`func1` will be used to resolve
         keys 'a', 'b' and 'c' and the function :func:`func2` will be used for
         keys 'd' and 'e'.  This could also be written as::
 
             __conflict_solve = dict(func1='a b c',func2='d e')
 
         These functions will be called for each key they apply to with the
         form::
 
             func1(self['a'], other['a'])
 
         The return value is used as the final merged value.
 
         As a convenience, merge() provides five (the most commonly needed)
         pre-defined policies: preserve, update, add, add_flip and add_s. The
         easiest explanation is their implementation::
 
             preserve = lambda old,new: old
             update   = lambda old,new: new
             add      = lambda old,new: old + new
             add_flip = lambda old,new: new + old  # note change of order!
             add_s    = lambda old,new: old + ' ' + new  # only for str!
 
         You can use those four words (as strings) as keys instead
         of defining them as functions, and the merge method will substitute
         the appropriate functions for you.
 
         For more complicated conflict resolution policies, you still need to
         construct your own functions.
 
         Examples
         --------
 
         This show the default policy:
 
         >>> s = Struct(a=10,b=30)
         >>> s2 = Struct(a=20,c=40)
         >>> s.merge(s2)
         >>> sorted(s.items())
         [('a', 10), ('b', 30), ('c', 40)]
 
         Now, show how to specify a conflict dict:
 
         >>> s = Struct(a=10,b=30)
         >>> s2 = Struct(a=20,b=40)
         >>> conflict = {'update':'a','add':'b'}
         >>> s.merge(s2,conflict)
         >>> sorted(s.items())
         [('a', 20), ('b', 70)]
         """
 
         data_dict = dict(__loc_data__,**kw)
 
         # policies for conflict resolution: two argument functions which return
         # the value that will go in the new struct
         preserve = lambda old,new: old
         update   = lambda old,new: new
         add      = lambda old,new: old + new
         add_flip = lambda old,new: new + old  # note change of order!
         add_s    = lambda old,new: old + ' ' + new
 
         # default policy is to keep current keys when there's a conflict
         conflict_solve = dict.fromkeys(self, preserve)
 
         # the conflict_solve dictionary is given by the user 'inverted': we
         # need a name-function mapping, it comes as a function -> names
         # dict. Make a local copy (b/c we'll make changes), replace user
         # strings for the three builtin policies and invert it.
         if __conflict_solve:
             inv_conflict_solve_user = __conflict_solve.copy()
             for name, func in [('preserve',preserve), ('update',update),
                                ('add',add), ('add_flip',add_flip),
                                ('add_s',add_s)]:
                 if name in inv_conflict_solve_user.keys():
                     inv_conflict_solve_user[func] = inv_conflict_solve_user[name]
                     del inv_conflict_solve_user[name]
             conflict_solve.update(self.__dict_invert(inv_conflict_solve_user))
         for key in data_dict:
             if key not in self:
                 self[key] = data_dict[key]
             else:
                 self[key] = conflict_solve[key](self[key],data_dict[key])
 

IPython/utils/path.py

@@ -1,436 +1,436 b''
 # encoding: utf-8
 """
 Utilities for path handling.
 """
 
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
 import os
 import sys
 import errno
 import shutil
 import random
 import glob
 from warnings import warn
 
 from IPython.utils.process import system
 from IPython.utils.decorators import undoc
 
 #-----------------------------------------------------------------------------
 # Code
 #-----------------------------------------------------------------------------
 fs_encoding = sys.getfilesystemencoding()
 
 def _writable_dir(path):
     """Whether `path` is a directory, to which the user has write access."""
     return os.path.isdir(path) and os.access(path, os.W_OK)
 
 if sys.platform == 'win32':
     def _get_long_path_name(path):
         """Get a long path name (expand ~) on Windows using ctypes.
 
         Examples
         --------
 
         >>> get_long_path_name('c:\\docume~1')
         'c:\\\\Documents and Settings'
 
         """
         try:
             import ctypes
-        except ImportError:
-            raise ImportError('you need to have ctypes installed for this to work')
+        except ImportError as e: 
+            raise ImportError('you need to have ctypes installed for this to work') from e
         _GetLongPathName = ctypes.windll.kernel32.GetLongPathNameW
         _GetLongPathName.argtypes = [ctypes.c_wchar_p, ctypes.c_wchar_p,
             ctypes.c_uint ]
 
         buf = ctypes.create_unicode_buffer(260)
         rv = _GetLongPathName(path, buf, 260)
         if rv == 0 or rv > 260:
             return path
         else:
             return buf.value
 else:
     def _get_long_path_name(path):
         """Dummy no-op."""
         return path
 
 
 
 def get_long_path_name(path):
     """Expand a path into its long form.
 
     On Windows this expands any ~ in the paths. On other platforms, it is
     a null operation.
     """
     return _get_long_path_name(path)
 
 
 def unquote_filename(name, win32=(sys.platform=='win32')):
     """ On Windows, remove leading and trailing quotes from filenames.
 
     This function has been deprecated and should not be used any more:
     unquoting is now taken care of by :func:`IPython.utils.process.arg_split`.
     """
     warn("'unquote_filename' is deprecated since IPython 5.0 and should not "
          "be used anymore", DeprecationWarning, stacklevel=2)
     if win32:
         if name.startswith(("'", '"')) and name.endswith(("'", '"')):
             name = name[1:-1]
     return name
 
 
 def compress_user(path):
     """Reverse of :func:`os.path.expanduser`
     """
     home = os.path.expanduser('~')
     if path.startswith(home):
         path =  "~" + path[len(home):]
     return path
 
 def get_py_filename(name, force_win32=None):
     """Return a valid python filename in the current directory.
 
     If the given name is not a file, it adds '.py' and searches again.
     Raises IOError with an informative message if the file isn't found.
     """
 
     name = os.path.expanduser(name)
     if force_win32 is not None:
         warn("The 'force_win32' argument to 'get_py_filename' is deprecated "
              "since IPython 5.0 and should not be used anymore",
             DeprecationWarning, stacklevel=2)
     if not os.path.isfile(name) and not name.endswith('.py'):
         name += '.py'
     if os.path.isfile(name):
         return name
     else:
         raise IOError('File `%r` not found.' % name)
 
 
 def filefind(filename, path_dirs=None):
     """Find a file by looking through a sequence of paths.
 
     This iterates through a sequence of paths looking for a file and returns
     the full, absolute path of the first occurrence of the file.  If no set of
     path dirs is given, the filename is tested as is, after running through
     :func:`expandvars` and :func:`expanduser`.  Thus a simple call::
 
         filefind('myfile.txt')
 
     will find the file in the current working dir, but::
 
         filefind('~/myfile.txt')
 
     Will find the file in the users home directory.  This function does not
     automatically try any paths, such as the cwd or the user's home directory.
 
     Parameters
     ----------
     filename : str
         The filename to look for.
     path_dirs : str, None or sequence of str
         The sequence of paths to look for the file in.  If None, the filename
         need to be absolute or be in the cwd.  If a string, the string is
         put into a sequence and the searched.  If a sequence, walk through
         each element and join with ``filename``, calling :func:`expandvars`
         and :func:`expanduser` before testing for existence.
 
     Returns
     -------
     Raises :exc:`IOError` or returns absolute path to file.
     """
 
     # If paths are quoted, abspath gets confused, strip them...
     filename = filename.strip('"').strip("'")
     # If the input is an absolute path, just check it exists
     if os.path.isabs(filename) and os.path.isfile(filename):
         return filename
 
     if path_dirs is None:
         path_dirs = ("",)
     elif isinstance(path_dirs, str):
         path_dirs = (path_dirs,)
 
     for path in path_dirs:
         if path == '.': path = os.getcwd()
         testname = expand_path(os.path.join(path, filename))
         if os.path.isfile(testname):
             return os.path.abspath(testname)
 
     raise IOError("File %r does not exist in any of the search paths: %r" %
                   (filename, path_dirs) )
 
 
 class HomeDirError(Exception):
     pass
 
 
 def get_home_dir(require_writable=False) -> str:
     """Return the 'home' directory, as a unicode string.
 
     Uses os.path.expanduser('~'), and checks for writability.
 
     See stdlib docs for how this is determined.
     For Python <3.8, $HOME is first priority on *ALL* platforms.
     For Python >=3.8 on Windows, %HOME% is no longer considered.
 
     Parameters
     ----------
 
     require_writable : bool [default: False]
         if True:
             guarantees the return value is a writable directory, otherwise
             raises HomeDirError
         if False:
             The path is resolved, but it is not guaranteed to exist or be writable.
     """
 
     homedir = os.path.expanduser('~')
     # Next line will make things work even when /home/ is a symlink to
     # /usr/home as it is on FreeBSD, for example
     homedir = os.path.realpath(homedir)
 
     if not _writable_dir(homedir) and os.name == 'nt':
         # expanduser failed, use the registry to get the 'My Documents' folder.
         try:
             import winreg as wreg
             with wreg.OpenKey(
                 wreg.HKEY_CURRENT_USER,
                 r"Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders"
             ) as key:
                 homedir = wreg.QueryValueEx(key,'Personal')[0]
         except:
             pass
 
     if (not require_writable) or _writable_dir(homedir):
         assert isinstance(homedir, str), "Homedir shoudl be unicode not bytes"
         return homedir
     else:
         raise HomeDirError('%s is not a writable dir, '
                 'set $HOME environment variable to override' % homedir)
 
 def get_xdg_dir():
     """Return the XDG_CONFIG_HOME, if it is defined and exists, else None.
 
     This is only for non-OS X posix (Linux,Unix,etc.) systems.
     """
 
     env = os.environ
 
     if os.name == 'posix' and sys.platform != 'darwin':
         # Linux, Unix, AIX, etc.
         # use ~/.config if empty OR not set
         xdg = env.get("XDG_CONFIG_HOME", None) or os.path.join(get_home_dir(), '.config')
         if xdg and _writable_dir(xdg):
             assert isinstance(xdg, str)
             return xdg
 
     return None
 
 
 def get_xdg_cache_dir():
     """Return the XDG_CACHE_HOME, if it is defined and exists, else None.
 
     This is only for non-OS X posix (Linux,Unix,etc.) systems.
     """
 
     env = os.environ
 
     if os.name == 'posix' and sys.platform != 'darwin':
         # Linux, Unix, AIX, etc.
         # use ~/.cache if empty OR not set
         xdg = env.get("XDG_CACHE_HOME", None) or os.path.join(get_home_dir(), '.cache')
         if xdg and _writable_dir(xdg):
             assert isinstance(xdg, str)
             return xdg
 
     return None
 
 
 @undoc
 def get_ipython_dir():
     warn("get_ipython_dir has moved to the IPython.paths module since IPython 4.0.", DeprecationWarning, stacklevel=2)
     from IPython.paths import get_ipython_dir
     return get_ipython_dir()
 
 @undoc
 def get_ipython_cache_dir():
     warn("get_ipython_cache_dir has moved to the IPython.paths module since IPython 4.0.", DeprecationWarning, stacklevel=2)
     from IPython.paths import get_ipython_cache_dir
     return get_ipython_cache_dir()
 
 @undoc
 def get_ipython_package_dir():
     warn("get_ipython_package_dir has moved to the IPython.paths module since IPython 4.0.", DeprecationWarning, stacklevel=2)
     from IPython.paths import get_ipython_package_dir
     return get_ipython_package_dir()
 
 @undoc
 def get_ipython_module_path(module_str):
     warn("get_ipython_module_path has moved to the IPython.paths module since IPython 4.0.", DeprecationWarning, stacklevel=2)
     from IPython.paths import get_ipython_module_path
     return get_ipython_module_path(module_str)
 
 @undoc
 def locate_profile(profile='default'):
     warn("locate_profile has moved to the IPython.paths module since IPython 4.0.", DeprecationWarning, stacklevel=2)
     from IPython.paths import locate_profile
     return locate_profile(profile=profile)
 
 def expand_path(s):
     """Expand $VARS and ~names in a string, like a shell
 
     :Examples:
 
        In [2]: os.environ['FOO']='test'
 
        In [3]: expand_path('variable FOO is $FOO')
        Out[3]: 'variable FOO is test'
     """
     # This is a pretty subtle hack. When expand user is given a UNC path
     # on Windows (\\server\share$\%username%), os.path.expandvars, removes
     # the $ to get (\\server\share\%username%). I think it considered $
     # alone an empty var. But, we need the $ to remains there (it indicates
     # a hidden share).
     if os.name=='nt':
         s = s.replace('$\\', 'IPYTHON_TEMP')
     s = os.path.expandvars(os.path.expanduser(s))
     if os.name=='nt':
         s = s.replace('IPYTHON_TEMP', '$\\')
     return s
 
 
 def unescape_glob(string):
     """Unescape glob pattern in `string`."""
     def unescape(s):
         for pattern in '*[]!?':
             s = s.replace(r'\{0}'.format(pattern), pattern)
         return s
     return '\\'.join(map(unescape, string.split('\\\\')))
 
 
 def shellglob(args):
     """
     Do glob expansion for each element in `args` and return a flattened list.
 
     Unmatched glob pattern will remain as-is in the returned list.
 
     """
     expanded = []
     # Do not unescape backslash in Windows as it is interpreted as
     # path separator:
     unescape = unescape_glob if sys.platform != 'win32' else lambda x: x
     for a in args:
         expanded.extend(glob.glob(a) or [unescape(a)])
     return expanded
 
 
 def target_outdated(target,deps):
     """Determine whether a target is out of date.
 
     target_outdated(target,deps) -> 1/0
 
     deps: list of filenames which MUST exist.
     target: single filename which may or may not exist.
 
     If target doesn't exist or is older than any file listed in deps, return
     true, otherwise return false.
     """
     try:
         target_time = os.path.getmtime(target)
     except os.error:
         return 1
     for dep in deps:
         dep_time = os.path.getmtime(dep)
         if dep_time > target_time:
             #print "For target",target,"Dep failed:",dep # dbg
             #print "times (dep,tar):",dep_time,target_time # dbg
             return 1
     return 0
 
 
 def target_update(target,deps,cmd):
     """Update a target with a given command given a list of dependencies.
 
     target_update(target,deps,cmd) -> runs cmd if target is outdated.
 
     This is just a wrapper around target_outdated() which calls the given
     command if target is outdated."""
 
     if target_outdated(target,deps):
         system(cmd)
 
 
 ENOLINK = 1998
 
 def link(src, dst):
     """Hard links ``src`` to ``dst``, returning 0 or errno.
 
     Note that the special errno ``ENOLINK`` will be returned if ``os.link`` isn't
     supported by the operating system.
     """
 
     if not hasattr(os, "link"):
         return ENOLINK
     link_errno = 0
     try:
         os.link(src, dst)
     except OSError as e:
         link_errno = e.errno
     return link_errno
 
 
 def link_or_copy(src, dst):
     """Attempts to hardlink ``src`` to ``dst``, copying if the link fails.
 
     Attempts to maintain the semantics of ``shutil.copy``.
 
     Because ``os.link`` does not overwrite files, a unique temporary file
     will be used if the target already exists, then that file will be moved
     into place.
     """
 
     if os.path.isdir(dst):
         dst = os.path.join(dst, os.path.basename(src))
 
     link_errno = link(src, dst)
     if link_errno == errno.EEXIST:
         if os.stat(src).st_ino == os.stat(dst).st_ino:
             # dst is already a hard link to the correct file, so we don't need
             # to do anything else. If we try to link and rename the file
             # anyway, we get duplicate files - see http://bugs.python.org/issue21876
             return
 
         new_dst = dst + "-temp-%04X" %(random.randint(1, 16**4), )
         try:
             link_or_copy(src, new_dst)
         except:
             try:
                 os.remove(new_dst)
             except OSError:
                 pass
             raise
         os.rename(new_dst, dst)
     elif link_errno != 0:
         # Either link isn't supported, or the filesystem doesn't support
         # linking, or 'src' and 'dst' are on different filesystems.
         shutil.copy(src, dst)
 
 def ensure_dir_exists(path, mode=0o755):
     """ensure that a directory exists
 
     If it doesn't exist, try to create it and protect against a race condition
     if another process is doing the same.
 
     The default permissions are 755, which differ from os.makedirs default of 777.
     """
     if not os.path.exists(path):
         try:
             os.makedirs(path, mode=mode)
         except OSError as e:
             if e.errno != errno.EEXIST:
                 raise
     elif not os.path.isdir(path):
         raise IOError("%r exists but is not a directory" % path)

IPython/utils/shimmodule.py

@@ -1,94 +1,94 b''
 """A shim module for deprecated imports
 """
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
 import sys
 import types
 from importlib import import_module
 
 from .importstring import import_item
 
 
 class ShimWarning(Warning):
     """A warning to show when a module has moved, and a shim is in its place."""
 
 class ShimImporter(object):
     """Import hook for a shim.
     
     This ensures that submodule imports return the real target module,
     not a clone that will confuse `is` and `isinstance` checks.
     """
     def __init__(self, src, mirror):
         self.src = src
         self.mirror = mirror
     
     def _mirror_name(self, fullname):
         """get the name of the mirrored module"""
         
         return self.mirror + fullname[len(self.src):]
 
     def find_module(self, fullname, path=None):
         """Return self if we should be used to import the module."""
         if fullname.startswith(self.src + '.'):
             mirror_name = self._mirror_name(fullname)
             try:
                 mod = import_item(mirror_name)
             except ImportError:
                 return
             else:
                 if not isinstance(mod, types.ModuleType):
                     # not a module
                     return None
                 return self
 
     def load_module(self, fullname):
         """Import the mirrored module, and insert it into sys.modules"""
         mirror_name = self._mirror_name(fullname)
         mod = import_item(mirror_name)
         sys.modules[fullname] = mod
         return mod
 
 
 class ShimModule(types.ModuleType):
 
     def __init__(self, *args, **kwargs):
         self._mirror = kwargs.pop("mirror")
         src = kwargs.pop("src", None)
         if src:
             kwargs['name'] = src.rsplit('.', 1)[-1]
         super(ShimModule, self).__init__(*args, **kwargs)
         # add import hook for descendent modules
         if src:
             sys.meta_path.append(
                 ShimImporter(src=src, mirror=self._mirror)
             )
     
     @property
     def __path__(self):
         return []
     
     @property
     def __spec__(self):
         """Don't produce __spec__ until requested"""
         return import_module(self._mirror).__spec__
     
     def __dir__(self):
         return dir(import_module(self._mirror))
     
     @property
     def __all__(self):
         """Ensure __all__ is always defined"""
         mod = import_module(self._mirror)
         try:
             return mod.__all__
         except AttributeError:
             return [name for name in dir(mod) if not name.startswith('_')]
 
     def __getattr__(self, key):
         # Use the equivalent of import_item(name), see below
         name = "%s.%s" % (self._mirror, key)
         try:
             return import_item(name)
-        except ImportError:
-            raise AttributeError(key)
+        except ImportError as e:
+            raise AttributeError(key) from e

docs/sphinxext/github.py

@@ -1,160 +1,160 b''
 """Define text roles for GitHub
 
 * ghissue - Issue
 * ghpull - Pull Request
 * ghuser - User
 
 Adapted from bitbucket example here:
 https://bitbucket.org/birkenfeld/sphinx-contrib/src/tip/bitbucket/sphinxcontrib/bitbucket.py
 
 Authors
 -------
 
 * Doug Hellmann
 * Min RK
 """
 #
 # Original Copyright (c) 2010 Doug Hellmann.  All rights reserved.
 #
 
 from docutils import nodes, utils
 from docutils.parsers.rst.roles import set_classes
 from sphinx.util.logging import getLogger
 
 info = getLogger(__name__).info
 
 def make_link_node(rawtext, app, type, slug, options):
     """Create a link to a github resource.
 
     :param rawtext: Text being replaced with link node.
     :param app: Sphinx application context
     :param type: Link type (issues, changeset, etc.)
     :param slug: ID of the thing to link to
     :param options: Options dictionary passed to role func.
     """
 
     try:
         base = app.config.github_project_url
         if not base:
             raise AttributeError
         if not base.endswith('/'):
             base += '/'
     except AttributeError as err:
-        raise ValueError('github_project_url configuration value is not set (%s)' % str(err))
+        raise ValueError('github_project_url configuration value is not set (%s)' % str(err)) from err
 
     ref = base + type + '/' + slug + '/'
     set_classes(options)
     prefix = "#"
     if type == 'pull':
         prefix = "PR " + prefix
     node = nodes.reference(rawtext, prefix + utils.unescape(slug), refuri=ref,
                            **options)
     return node
 
 def ghissue_role(name, rawtext, text, lineno, inliner, options={}, content=[]):
     """Link to a GitHub issue.
 
     Returns 2 part tuple containing list of nodes to insert into the
     document and a list of system messages.  Both are allowed to be
     empty.
 
     :param name: The role name used in the document.
     :param rawtext: The entire markup snippet, with role.
     :param text: The text marked with the role.
     :param lineno: The line number where rawtext appears in the input.
     :param inliner: The inliner instance that called us.
     :param options: Directive options for customization.
     :param content: The directive content for customization.
     """
 
     try:
         issue_num = int(text)
         if issue_num <= 0:
             raise ValueError
     except ValueError:
         msg = inliner.reporter.error(
             'GitHub issue number must be a number greater than or equal to 1; '
             '"%s" is invalid.' % text, line=lineno)
         prb = inliner.problematic(rawtext, rawtext, msg)
         return [prb], [msg]
     app = inliner.document.settings.env.app
     #info('issue %r' % text)
     if 'pull' in name.lower():
         category = 'pull'
     elif 'issue' in name.lower():
         category = 'issues'
     else:
         msg = inliner.reporter.error(
             'GitHub roles include "ghpull" and "ghissue", '
             '"%s" is invalid.' % name, line=lineno)
         prb = inliner.problematic(rawtext, rawtext, msg)
         return [prb], [msg]
     node = make_link_node(rawtext, app, category, str(issue_num), options)
     return [node], []
 
 def ghuser_role(name, rawtext, text, lineno, inliner, options={}, content=[]):
     """Link to a GitHub user.
 
     Returns 2 part tuple containing list of nodes to insert into the
     document and a list of system messages.  Both are allowed to be
     empty.
 
     :param name: The role name used in the document.
     :param rawtext: The entire markup snippet, with role.
     :param text: The text marked with the role.
     :param lineno: The line number where rawtext appears in the input.
     :param inliner: The inliner instance that called us.
     :param options: Directive options for customization.
     :param content: The directive content for customization.
     """
     app = inliner.document.settings.env.app
     #info('user link %r' % text)
     ref = 'https://www.github.com/' + text
     node = nodes.reference(rawtext, text, refuri=ref, **options)
     return [node], []
 
 def ghcommit_role(name, rawtext, text, lineno, inliner, options={}, content=[]):
     """Link to a GitHub commit.
 
     Returns 2 part tuple containing list of nodes to insert into the
     document and a list of system messages.  Both are allowed to be
     empty.
 
     :param name: The role name used in the document.
     :param rawtext: The entire markup snippet, with role.
     :param text: The text marked with the role.
     :param lineno: The line number where rawtext appears in the input.
     :param inliner: The inliner instance that called us.
     :param options: Directive options for customization.
     :param content: The directive content for customization.
     """
     app = inliner.document.settings.env.app
     #info('user link %r' % text)
     try:
         base = app.config.github_project_url
         if not base:
             raise AttributeError
         if not base.endswith('/'):
             base += '/'
     except AttributeError as err:
-        raise ValueError('github_project_url configuration value is not set (%s)' % str(err))
+        raise ValueError('github_project_url configuration value is not set (%s)' % str(err)) from err
 
     ref = base + text
     node = nodes.reference(rawtext, text[:6], refuri=ref, **options)
     return [node], []
 
 
 def setup(app):
     """Install the plugin.
 
     :param app: Sphinx application context.
     """
     info('Initializing GitHub plugin')
     app.add_role('ghissue', ghissue_role)
     app.add_role('ghpull', ghissue_role)
     app.add_role('ghuser', ghuser_role)
     app.add_role('ghcommit', ghcommit_role)
     app.add_config_value('github_project_url', None, 'env')
 
     metadata = {'parallel_read_safe': True, 'parallel_write_safe': True}
     return metadata

tools/gh_api.py

@@ -1,303 +1,303 b''
 """Functions for Github API requests."""
 
 try:
     input = raw_input
 except NameError:
     pass
 
 import os
 import re
 import sys
 
 import requests
 import getpass
 import json
 
 try:
     import requests_cache
 except ImportError:
     print("cache not available, install `requests_cache` for caching.", file=sys.stderr)
 else:
     requests_cache.install_cache("gh_api", expire_after=3600)
 
 # Keyring stores passwords by a 'username', but we're not storing a username and
 # password
 import socket
 fake_username = 'ipython_tools_%s' % socket.gethostname().replace('.','_').replace('-','_')
 
 class Obj(dict):
     """Dictionary with attribute access to names."""
     def __getattr__(self, name):
         try:
             return self[name]
-        except KeyError:
-            raise AttributeError(name)
+        except KeyError as e:
+            raise AttributeError(name) from e
 
     def __setattr__(self, name, val):
         self[name] = val
 
 token = None
 def get_auth_token():
     global token
 
     if token is not None:
         return token
 
     import keyring
     token = keyring.get_password('github', fake_username)
     if token is not None:
         return token
 
     print("Please enter your github username and password. These are not "
           "stored, only used to get an oAuth token. You can revoke this at "
           "any time on Github.\n"
           "Username: ", file=sys.stderr, end='')
     user = input('')
     pw = getpass.getpass("Password: ", stream=sys.stderr)
 
     auth_request = {
       "scopes": [
         "public_repo",
         "gist"
       ],
       "note": "IPython tools %s" % socket.gethostname(),
       "note_url": "https://github.com/ipython/ipython/tree/master/tools",
     }
     response = requests.post('https://api.github.com/authorizations',
                             auth=(user, pw), data=json.dumps(auth_request))
     if response.status_code == 401 and \
             'required;' in response.headers.get('X-GitHub-OTP', ''):
         print("Your login API requested a one time password", file=sys.stderr)
         otp = getpass.getpass("One Time Password: ", stream=sys.stderr)
         response = requests.post('https://api.github.com/authorizations',
                             auth=(user, pw), 
                             data=json.dumps(auth_request),
                             headers={'X-GitHub-OTP':otp})
     response.raise_for_status()
     token = json.loads(response.text)['token']
     keyring.set_password('github', fake_username, token)
     return token
 
 def make_auth_header():
     return {'Authorization': 'token ' + get_auth_token()}
 
 def post_issue_comment(project, num, body):
     url = 'https://api.github.com/repos/{project}/issues/{num}/comments'.format(project=project, num=num)
     payload = json.dumps({'body': body})
     requests.post(url, data=payload, headers=make_auth_header())
 
 def post_gist(content, description='', filename='file', auth=False):
     """Post some text to a Gist, and return the URL."""
     post_data = json.dumps({
       "description": description,
       "public": True,
       "files": {
         filename: {
           "content": content
         }
       }
     }).encode('utf-8')
 
     headers = make_auth_header() if auth else {}
     response = requests.post("https://api.github.com/gists", data=post_data, headers=headers)
     response.raise_for_status()
     response_data = json.loads(response.text)
     return response_data['html_url']
 
 def get_pull_request(project, num, auth=False):
     """get pull request info  by number
     """
     url = "https://api.github.com/repos/{project}/pulls/{num}".format(project=project, num=num)
     if auth:
         header = make_auth_header()
     else:
         header = None
     print("fetching %s" % url, file=sys.stderr)
     response = requests.get(url, headers=header)
     response.raise_for_status()
     return json.loads(response.text, object_hook=Obj)
 
 def get_pull_request_files(project, num, auth=False):
     """get list of files in a pull request"""
     url = "https://api.github.com/repos/{project}/pulls/{num}/files".format(project=project, num=num)
     if auth:
         header = make_auth_header()
     else:
         header = None
     return get_paged_request(url, headers=header)
 
 element_pat = re.compile(r'<(.+?)>')
 rel_pat = re.compile(r'rel=[\'"](\w+)[\'"]')
 
 def get_paged_request(url, headers=None, **params):
     """get a full list, handling APIv3's paging"""
     results = []
     params.setdefault("per_page", 100)
     while True:
         if '?' in url:
             params = None
             print("fetching %s" % url, file=sys.stderr)
         else:
             print("fetching %s with %s" % (url, params), file=sys.stderr)
         response = requests.get(url, headers=headers, params=params)
         response.raise_for_status()
         results.extend(response.json())
         if 'next' in response.links:
             url = response.links['next']['url']
         else:
             break
     return results
 
 def get_pulls_list(project, auth=False, **params):
     """get pull request list"""
     params.setdefault("state", "closed")
     url = "https://api.github.com/repos/{project}/pulls".format(project=project)
     if auth:
         headers = make_auth_header()
     else:
         headers = None
     pages = get_paged_request(url, headers=headers, **params)
     return pages
 
 def get_issues_list(project, auth=False, **params):
     """get issues list"""
     params.setdefault("state", "closed")
     url = "https://api.github.com/repos/{project}/issues".format(project=project)
     if auth:
         headers = make_auth_header()
     else:
         headers = None
     pages = get_paged_request(url, headers=headers, **params)
     return pages
 
 def get_milestones(project, auth=False, **params):
     params.setdefault('state', 'all')
     url = "https://api.github.com/repos/{project}/milestones".format(project=project)
     if auth:
         headers = make_auth_header()
     else:
         headers = None
     milestones = get_paged_request(url, headers=headers, **params)
     return milestones
 
 def get_milestone_id(project, milestone, auth=False, **params):
     milestones = get_milestones(project, auth=auth, **params)
     for mstone in milestones:
         if mstone['title'] == milestone:
             return mstone['number']
     else:
         raise ValueError("milestone %s not found" % milestone)
 
 def is_pull_request(issue):
     """Return True if the given issue is a pull request."""
     return bool(issue.get('pull_request', {}).get('html_url', None))
 
 def get_authors(pr):
     print("getting authors for #%i" % pr['number'], file=sys.stderr)
     h = make_auth_header()
     r = requests.get(pr['commits_url'], headers=h)
     r.raise_for_status()
     commits = r.json()
     authors = []
     for commit in commits:
         author = commit['commit']['author']
         authors.append("%s <%s>" % (author['name'], author['email']))
     return authors
 
 # encode_multipart_formdata is from urllib3.filepost
 # The only change is to iter_fields, to enforce S3's required key ordering
 
 def iter_fields(fields):
     fields = fields.copy()
     for key in ('key', 'acl', 'Filename', 'success_action_status', 'AWSAccessKeyId',
         'Policy', 'Signature', 'Content-Type', 'file'):
         yield (key, fields.pop(key))
     for (k,v) in fields.items():
         yield k,v
 
 def encode_multipart_formdata(fields, boundary=None):
     """
     Encode a dictionary of ``fields`` using the multipart/form-data mime format.
 
     :param fields:
         Dictionary of fields or list of (key, value) field tuples.  The key is
         treated as the field name, and the value as the body of the form-data
         bytes. If the value is a tuple of two elements, then the first element
         is treated as the filename of the form-data section.
 
         Field names and filenames must be unicode.
 
     :param boundary:
         If not specified, then a random boundary will be generated using
         :func:`mimetools.choose_boundary`.
     """
     # copy requests imports in here:
     from io import BytesIO
     from requests.packages.urllib3.filepost import (
         choose_boundary, six, writer, b, get_content_type
     )
     body = BytesIO()
     if boundary is None:
         boundary = choose_boundary()
 
     for fieldname, value in iter_fields(fields):
         body.write(b('--%s\r\n' % (boundary)))
 
         if isinstance(value, tuple):
             filename, data = value
             writer(body).write('Content-Disposition: form-data; name="%s"; '
                                'filename="%s"\r\n' % (fieldname, filename))
             body.write(b('Content-Type: %s\r\n\r\n' %
                        (get_content_type(filename))))
         else:
             data = value
             writer(body).write('Content-Disposition: form-data; name="%s"\r\n'
                                % (fieldname))
             body.write(b'Content-Type: text/plain\r\n\r\n')
 
         if isinstance(data, int):
             data = str(data)  # Backwards compatibility
         if isinstance(data, six.text_type):
             writer(body).write(data)
         else:
             body.write(data)
 
         body.write(b'\r\n')
 
     body.write(b('--%s--\r\n' % (boundary)))
 
     content_type = b('multipart/form-data; boundary=%s' % boundary)
 
     return body.getvalue(), content_type
 
 
 def post_download(project, filename, name=None, description=""):
     """Upload a file to the GitHub downloads area"""
     if name is None:
         name = os.path.basename(filename)
     with open(filename, 'rb') as f:
         filedata = f.read()
 
     url = "https://api.github.com/repos/{project}/downloads".format(project=project)
 
     payload = json.dumps(dict(name=name, size=len(filedata),
                     description=description))
     response = requests.post(url, data=payload, headers=make_auth_header())
     response.raise_for_status()
     reply = json.loads(response.content)
     s3_url = reply['s3_url']
 
     fields = dict(
         key=reply['path'],
         acl=reply['acl'],
         success_action_status=201,
         Filename=reply['name'],
         AWSAccessKeyId=reply['accesskeyid'],
         Policy=reply['policy'],
         Signature=reply['signature'],
         file=(reply['name'], filedata),
     )
     fields['Content-Type'] = reply['mime_type']
     data, content_type = encode_multipart_formdata(fields)
     s3r = requests.post(s3_url, data=data, headers={'Content-Type': content_type})
     return s3r