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Merge pull request #12437 from impact27/patch-3...
Merge pull request #12437 from impact27/patch-3 PR: Move extraction of local scope to a method

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display.py
651 lines | 23.5 KiB | text/x-python | PythonLexer
"""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 as e:
raise TypeError('Only lists of mono audio are '
'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())