Deprecate io.{stdout,stderr} and shell.{write,write_err}

I believe there is no longer any reason to use these

IPython/core/debugger.py

@@ -1,637 +1,637 b''
 # -*- coding: utf-8 -*-
 """
 Pdb debugger class.
 
 Modified from the standard pdb.Pdb class to avoid including readline, so that
 the command line completion of other programs which include this isn't
 damaged.
 
 In the future, this class will be expanded with improvements over the standard
 pdb.
 
 The code in this file is mainly lifted out of cmd.py in Python 2.2, with minor
 changes. Licensing should therefore be under the standard Python terms.  For
 details on the PSF (Python Software Foundation) standard license, see:
 
 http://www.python.org/2.2.3/license.html"""
 
 #*****************************************************************************
 #
 #       This file is licensed under the PSF license.
 #
 #       Copyright (C) 2001 Python Software Foundation, www.python.org
 #       Copyright (C) 2005-2006 Fernando Perez. <[e-mail]>
 #
 #
 #*****************************************************************************
 from __future__ import print_function
 
 import bdb
 import functools
 import inspect
 import sys
 
 from IPython import get_ipython
 from IPython.utils import PyColorize, ulinecache
-from IPython.utils import coloransi, io, py3compat
+from IPython.utils import coloransi, py3compat
 from IPython.core.excolors import exception_colors
 from IPython.testing.skipdoctest import skip_doctest
 
 # See if we can use pydb.
 has_pydb = False
 prompt = 'ipdb> '
 #We have to check this directly from sys.argv, config struct not yet available
 if '--pydb' in sys.argv:
     try:
         import pydb
         if hasattr(pydb.pydb, "runl") and pydb.version>'1.17':
             # Version 1.17 is broken, and that's what ships with Ubuntu Edgy, so we
             # better protect against it.
             has_pydb = True
     except ImportError:
         print("Pydb (http://bashdb.sourceforge.net/pydb/) does not seem to be available")
 
 if has_pydb:
     from pydb import Pdb as OldPdb
     prompt = 'ipydb> '
 else:
     from pdb import Pdb as OldPdb
 
 # Allow the set_trace code to operate outside of an ipython instance, even if
 # it does so with some limitations.  The rest of this support is implemented in
 # the Tracer constructor.
 
 def make_arrow(pad):
     """generate the leading arrow in front of traceback or debugger"""
     if pad >= 2:
         return '-'*(pad-2) + '> '
     elif pad == 1:
         return '>'
     return ''
 
 
 def BdbQuit_excepthook(et, ev, tb, excepthook=None):
     """Exception hook which handles `BdbQuit` exceptions.
 
     All other exceptions are processed using the `excepthook`
     parameter.
     """
     if et==bdb.BdbQuit:
         print('Exiting Debugger.')
     elif excepthook is not None:
         excepthook(et, ev, tb)
     else:
         # Backwards compatibility. Raise deprecation warning?
         BdbQuit_excepthook.excepthook_ori(et,ev,tb)
 
 def BdbQuit_IPython_excepthook(self,et,ev,tb,tb_offset=None):
     print('Exiting Debugger.')
 
 
 class Tracer(object):
     """Class for local debugging, similar to pdb.set_trace.
 
     Instances of this class, when called, behave like pdb.set_trace, but
     providing IPython's enhanced capabilities.
 
     This is implemented as a class which must be initialized in your own code
     and not as a standalone function because we need to detect at runtime
     whether IPython is already active or not.  That detection is done in the
     constructor, ensuring that this code plays nicely with a running IPython,
     while functioning acceptably (though with limitations) if outside of it.
     """
 
     @skip_doctest
     def __init__(self, colors=None):
         """Create a local debugger instance.
 
         Parameters
         ----------
 
         colors : str, optional
             The name of the color scheme to use, it must be one of IPython's
             valid color schemes.  If not given, the function will default to
             the current IPython scheme when running inside IPython, and to
             'NoColor' otherwise.
 
         Examples
         --------
         ::
 
             from IPython.core.debugger import Tracer; debug_here = Tracer()
 
         Later in your code::
 
             debug_here()  # -> will open up the debugger at that point.
 
         Once the debugger activates, you can use all of its regular commands to
         step through code, set breakpoints, etc.  See the pdb documentation
         from the Python standard library for usage details.
         """
 
         ip = get_ipython()
         if ip is None:
             # Outside of ipython, we set our own exception hook manually
             sys.excepthook = functools.partial(BdbQuit_excepthook,
                                                excepthook=sys.excepthook)
             def_colors = 'NoColor'
             try:
                 # Limited tab completion support
                 import readline
                 readline.parse_and_bind('tab: complete')
             except ImportError:
                 pass
         else:
             # In ipython, we use its custom exception handler mechanism
             def_colors = ip.colors
             ip.set_custom_exc((bdb.BdbQuit,), BdbQuit_IPython_excepthook)
 
         if colors is None:
             colors = def_colors
 
         # The stdlib debugger internally uses a modified repr from the `repr`
         # module, that limits the length of printed strings to a hardcoded
         # limit of 30 characters.  That much trimming is too aggressive, let's
         # at least raise that limit to 80 chars, which should be enough for
         # most interactive uses.
         try:
             try:
                 from reprlib import aRepr  # Py 3
             except ImportError:
                 from repr import aRepr  # Py 2
             aRepr.maxstring = 80
         except:
             # This is only a user-facing convenience, so any error we encounter
             # here can be warned about but can be otherwise ignored.  These
             # printouts will tell us about problems if this API changes
             import traceback
             traceback.print_exc()
 
         self.debugger = Pdb(colors)
 
     def __call__(self):
         """Starts an interactive debugger at the point where called.
 
         This is similar to the pdb.set_trace() function from the std lib, but
         using IPython's enhanced debugger."""
 
         self.debugger.set_trace(sys._getframe().f_back)
 
 
 def decorate_fn_with_doc(new_fn, old_fn, additional_text=""):
     """Make new_fn have old_fn's doc string. This is particularly useful
     for the ``do_...`` commands that hook into the help system.
     Adapted from from a comp.lang.python posting
     by Duncan Booth."""
     def wrapper(*args, **kw):
         return new_fn(*args, **kw)
     if old_fn.__doc__:
         wrapper.__doc__ = old_fn.__doc__ + additional_text
     return wrapper
 
 
 def _file_lines(fname):
     """Return the contents of a named file as a list of lines.
 
     This function never raises an IOError exception: if the file can't be
     read, it simply returns an empty list."""
 
     try:
         outfile = open(fname)
     except IOError:
         return []
     else:
         out = outfile.readlines()
         outfile.close()
         return out
 
 
 class Pdb(OldPdb):
     """Modified Pdb class, does not load readline."""
 
     def __init__(self,color_scheme='NoColor',completekey=None,
                  stdin=None, stdout=None, context=5):
 
         # Parent constructor:
         try:
             self.context=int(context)
             if self.context <= 0:
                 raise ValueError("Context must be a positive integer")
         except (TypeError, ValueError):
                 raise ValueError("Context must be a positive integer")
 
         if has_pydb and completekey is None:
-            OldPdb.__init__(self,stdin=stdin,stdout=io.stdout)
+            OldPdb.__init__(self,stdin=stdin,stdout=sys.stdout)
         else:
             OldPdb.__init__(self,completekey,stdin,stdout)
 
         # IPython changes...
         self.is_pydb = has_pydb
 
         self.shell = get_ipython()
 
         if self.shell is None:
             # No IPython instance running, we must create one
             from IPython.terminal.interactiveshell import \
                 TerminalInteractiveShell
             self.shell = TerminalInteractiveShell.instance()
 
         if self.is_pydb:
 
             # interactiveshell.py's ipalias seems to want pdb's checkline
             # which located in pydb.fn
             import pydb.fns
             self.checkline = lambda filename, lineno: \
                              pydb.fns.checkline(self, filename, lineno)
 
             self.curframe = None
             self.do_restart = self.new_do_restart
 
             self.old_all_completions = self.shell.Completer.all_completions
             self.shell.Completer.all_completions=self.all_completions
 
             self.do_list = decorate_fn_with_doc(self.list_command_pydb,
                                                 OldPdb.do_list)
             self.do_l     = self.do_list
             self.do_frame = decorate_fn_with_doc(self.new_do_frame,
                                                  OldPdb.do_frame)
 
         self.aliases = {}
 
         # Create color table: we copy the default one from the traceback
         # module and add a few attributes needed for debugging
         self.color_scheme_table = exception_colors()
 
         # shorthands
         C = coloransi.TermColors
         cst = self.color_scheme_table
 
         cst['NoColor'].colors.prompt = C.NoColor
         cst['NoColor'].colors.breakpoint_enabled = C.NoColor
         cst['NoColor'].colors.breakpoint_disabled = C.NoColor
 
         cst['Linux'].colors.prompt = C.Green
         cst['Linux'].colors.breakpoint_enabled = C.LightRed
         cst['Linux'].colors.breakpoint_disabled = C.Red
 
         cst['LightBG'].colors.prompt = C.Blue
         cst['LightBG'].colors.breakpoint_enabled = C.LightRed
         cst['LightBG'].colors.breakpoint_disabled = C.Red
 
         self.set_colors(color_scheme)
 
         # Add a python parser so we can syntax highlight source while
         # debugging.
         self.parser = PyColorize.Parser()
 
         # Set the prompt - the default prompt is '(Pdb)'
         Colors = cst.active_colors
         if color_scheme == 'NoColor':
             self.prompt = prompt
         else:
             # The colour markers are wrapped by bytes 01 and 02 so that readline
             # can calculate the width.
             self.prompt = u'\x01%s\x02%s\x01%s\x02' % (Colors.prompt, prompt, Colors.Normal)
 
     def set_colors(self, scheme):
         """Shorthand access to the color table scheme selector method."""
         self.color_scheme_table.set_active_scheme(scheme)
 
     def interaction(self, frame, traceback):
         self.shell.set_completer_frame(frame)
         while True:
             try:
                 OldPdb.interaction(self, frame, traceback)
                 break
             except KeyboardInterrupt:
                 self.shell.write('\n' + self.shell.get_exception_only())
                 break
             finally:
                 # Pdb sets readline delimiters, so set them back to our own
                 if self.shell.readline is not None:
                     self.shell.readline.set_completer_delims(self.shell.readline_delims)
 
     def new_do_up(self, arg):
         OldPdb.do_up(self, arg)
         self.shell.set_completer_frame(self.curframe)
     do_u = do_up = decorate_fn_with_doc(new_do_up, OldPdb.do_up)
 
     def new_do_down(self, arg):
         OldPdb.do_down(self, arg)
         self.shell.set_completer_frame(self.curframe)
 
     do_d = do_down = decorate_fn_with_doc(new_do_down, OldPdb.do_down)
 
     def new_do_frame(self, arg):
         OldPdb.do_frame(self, arg)
         self.shell.set_completer_frame(self.curframe)
 
     def new_do_quit(self, arg):
 
         if hasattr(self, 'old_all_completions'):
             self.shell.Completer.all_completions=self.old_all_completions
 
         return OldPdb.do_quit(self, arg)
 
     do_q = do_quit = decorate_fn_with_doc(new_do_quit, OldPdb.do_quit)
 
     def new_do_restart(self, arg):
         """Restart command. In the context of ipython this is exactly the same
         thing as 'quit'."""
         self.msg("Restart doesn't make sense here. Using 'quit' instead.")
         return self.do_quit(arg)
 
     def postloop(self):
         self.shell.set_completer_frame(None)
 
     def print_stack_trace(self, context=None):
         if context is None:
             context = self.context
         try:
             context=int(context)
             if context <= 0:
                 raise ValueError("Context must be a positive integer")
         except (TypeError, ValueError):
                 raise ValueError("Context must be a positive integer")
         try:
             for frame_lineno in self.stack:
                 self.print_stack_entry(frame_lineno, context=context)
         except KeyboardInterrupt:
             pass
 
     def print_stack_entry(self,frame_lineno,prompt_prefix='\n-> ',
                           context=None):
         if context is None:
             context = self.context
         try:
             context=int(context)
             if context <= 0:
                 raise ValueError("Context must be a positive integer")
         except (TypeError, ValueError):
                 raise ValueError("Context must be a positive integer")
-        print(self.format_stack_entry(frame_lineno, '', context), file=io.stdout)
+        print(self.format_stack_entry(frame_lineno, '', context))
 
         # vds: >>
         frame, lineno = frame_lineno
         filename = frame.f_code.co_filename
         self.shell.hooks.synchronize_with_editor(filename, lineno, 0)
         # vds: <<
 
     def format_stack_entry(self, frame_lineno, lprefix=': ', context=None):
         if context is None:
             context = self.context
         try:
             context=int(context)
             if context <= 0:
                 print("Context must be a positive integer")
         except (TypeError, ValueError):
                 print("Context must be a positive integer")
         try:
             import reprlib  # Py 3
         except ImportError:
             import repr as reprlib  # Py 2
 
         ret = []
 
         Colors = self.color_scheme_table.active_colors
         ColorsNormal = Colors.Normal
         tpl_link = u'%s%%s%s' % (Colors.filenameEm, ColorsNormal)
         tpl_call = u'%s%%s%s%%s%s' % (Colors.vName, Colors.valEm, ColorsNormal)
         tpl_line = u'%%s%s%%s %s%%s' % (Colors.lineno, ColorsNormal)
         tpl_line_em = u'%%s%s%%s %s%%s%s' % (Colors.linenoEm, Colors.line,
                                             ColorsNormal)
 
         frame, lineno = frame_lineno
 
         return_value = ''
         if '__return__' in frame.f_locals:
             rv = frame.f_locals['__return__']
             #return_value += '->'
             return_value += reprlib.repr(rv) + '\n'
         ret.append(return_value)
 
         #s = filename + '(' + `lineno` + ')'
         filename = self.canonic(frame.f_code.co_filename)
         link = tpl_link % py3compat.cast_unicode(filename)
 
         if frame.f_code.co_name:
             func = frame.f_code.co_name
         else:
             func = "<lambda>"
 
         call = ''
         if func != '?':
             if '__args__' in frame.f_locals:
                 args = reprlib.repr(frame.f_locals['__args__'])
             else:
                 args = '()'
             call = tpl_call % (func, args)
 
         # The level info should be generated in the same format pdb uses, to
         # avoid breaking the pdbtrack functionality of python-mode in *emacs.
         if frame is self.curframe:
             ret.append('> ')
         else:
             ret.append('  ')
         ret.append(u'%s(%s)%s\n' % (link,lineno,call))
 
         start = lineno - 1 - context//2
         lines = ulinecache.getlines(filename)
         start = min(start, len(lines) - context)
         start = max(start, 0)
         lines = lines[start : start + context]
 
         for i,line in enumerate(lines):
             show_arrow = (start + 1 + i == lineno)
             linetpl = (frame is self.curframe or show_arrow) \
                       and tpl_line_em \
                       or tpl_line
             ret.append(self.__format_line(linetpl, filename,
                                           start + 1 + i, line,
                                           arrow = show_arrow) )
         return ''.join(ret)
 
     def __format_line(self, tpl_line, filename, lineno, line, arrow = False):
         bp_mark = ""
         bp_mark_color = ""
 
         scheme = self.color_scheme_table.active_scheme_name
         new_line, err = self.parser.format2(line, 'str', scheme)
         if not err: line = new_line
 
         bp = None
         if lineno in self.get_file_breaks(filename):
             bps = self.get_breaks(filename, lineno)
             bp = bps[-1]
 
         if bp:
             Colors = self.color_scheme_table.active_colors
             bp_mark = str(bp.number)
             bp_mark_color = Colors.breakpoint_enabled
             if not bp.enabled:
                 bp_mark_color = Colors.breakpoint_disabled
 
         numbers_width = 7
         if arrow:
             # This is the line with the error
             pad = numbers_width - len(str(lineno)) - len(bp_mark)
             num = '%s%s' % (make_arrow(pad), str(lineno))
         else:
             num = '%*s' % (numbers_width - len(bp_mark), str(lineno))
 
         return tpl_line % (bp_mark_color + bp_mark, num, line)
 
 
     def list_command_pydb(self, arg):
         """List command to use if we have a newer pydb installed"""
         filename, first, last = OldPdb.parse_list_cmd(self, arg)
         if filename is not None:
             self.print_list_lines(filename, first, last)
 
     def print_list_lines(self, filename, first, last):
         """The printing (as opposed to the parsing part of a 'list'
         command."""
         try:
             Colors = self.color_scheme_table.active_colors
             ColorsNormal = Colors.Normal
             tpl_line = '%%s%s%%s %s%%s' % (Colors.lineno, ColorsNormal)
             tpl_line_em = '%%s%s%%s %s%%s%s' % (Colors.linenoEm, Colors.line, ColorsNormal)
             src = []
             if filename == "<string>" and hasattr(self, "_exec_filename"):
                 filename = self._exec_filename
 
             for lineno in range(first, last+1):
                 line = ulinecache.getline(filename, lineno)
                 if not line:
                     break
 
                 if lineno == self.curframe.f_lineno:
                     line = self.__format_line(tpl_line_em, filename, lineno, line, arrow = True)
                 else:
                     line = self.__format_line(tpl_line, filename, lineno, line, arrow = False)
 
                 src.append(line)
                 self.lineno = lineno
 
-            print(''.join(src), file=io.stdout)
+            print(''.join(src))
 
         except KeyboardInterrupt:
             pass
 
     def do_list(self, arg):
         self.lastcmd = 'list'
         last = None
         if arg:
             try:
                 x = eval(arg, {}, {})
                 if type(x) == type(()):
                     first, last = x
                     first = int(first)
                     last = int(last)
                     if last < first:
                         # Assume it's a count
                         last = first + last
                 else:
                     first = max(1, int(x) - 5)
             except:
                 print('*** Error in argument:', repr(arg))
                 return
         elif self.lineno is None:
             first = max(1, self.curframe.f_lineno - 5)
         else:
             first = self.lineno + 1
         if last is None:
             last = first + 10
         self.print_list_lines(self.curframe.f_code.co_filename, first, last)
 
         # vds: >>
         lineno = first
         filename = self.curframe.f_code.co_filename
         self.shell.hooks.synchronize_with_editor(filename, lineno, 0)
         # vds: <<
 
     do_l = do_list
 
     def getsourcelines(self, obj):
         lines, lineno = inspect.findsource(obj)
         if inspect.isframe(obj) and obj.f_globals is obj.f_locals:
             # must be a module frame: do not try to cut a block out of it
             return lines, 1
         elif inspect.ismodule(obj):
             return lines, 1
         return inspect.getblock(lines[lineno:]), lineno+1
 
     def do_longlist(self, arg):
         self.lastcmd = 'longlist'
         try:
             lines, lineno = self.getsourcelines(self.curframe)
         except OSError as err:
             self.error(err)
             return
         last = lineno + len(lines)
         self.print_list_lines(self.curframe.f_code.co_filename, lineno, last)
     do_ll = do_longlist
 
     def do_pdef(self, arg):
         """Print the call signature for any callable object.
 
         The debugger interface to %pdef"""
         namespaces = [('Locals', self.curframe.f_locals),
                       ('Globals', self.curframe.f_globals)]
         self.shell.find_line_magic('pdef')(arg, namespaces=namespaces)
 
     def do_pdoc(self, arg):
         """Print the docstring for an object.
 
         The debugger interface to %pdoc."""
         namespaces = [('Locals', self.curframe.f_locals),
                       ('Globals', self.curframe.f_globals)]
         self.shell.find_line_magic('pdoc')(arg, namespaces=namespaces)
 
     def do_pfile(self, arg):
         """Print (or run through pager) the file where an object is defined.
 
         The debugger interface to %pfile.
         """
         namespaces = [('Locals', self.curframe.f_locals),
                       ('Globals', self.curframe.f_globals)]
         self.shell.find_line_magic('pfile')(arg, namespaces=namespaces)
 
     def do_pinfo(self, arg):
         """Provide detailed information about an object.
 
         The debugger interface to %pinfo, i.e., obj?."""
         namespaces = [('Locals', self.curframe.f_locals),
                       ('Globals', self.curframe.f_globals)]
         self.shell.find_line_magic('pinfo')(arg, namespaces=namespaces)
 
     def do_pinfo2(self, arg):
         """Provide extra detailed information about an object.
 
         The debugger interface to %pinfo2, i.e., obj??."""
         namespaces = [('Locals', self.curframe.f_locals),
                       ('Globals', self.curframe.f_globals)]
         self.shell.find_line_magic('pinfo2')(arg, namespaces=namespaces)
 
     def do_psource(self, arg):
         """Print (or run through pager) the source code for an object."""
         namespaces = [('Locals', self.curframe.f_locals),
                       ('Globals', self.curframe.f_globals)]
         self.shell.find_line_magic('psource')(arg, namespaces=namespaces)
 
     if sys.version_info > (3, ):
         def do_where(self, arg):
             """w(here)
             Print a stack trace, with the most recent frame at the bottom.
             An arrow indicates the "current frame", which determines the
             context of most commands. 'bt' is an alias for this command.
 
             Take a number as argument as an (optional) number of context line to
             print"""
             if arg:
                 context = int(arg)
                 self.print_stack_trace(context)
             else:
                 self.print_stack_trace()
 
         do_w = do_where

IPython/core/display.py

@@ -1,1004 +1,1004 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 __future__ import print_function
 
 try:
     from base64 import encodebytes as base64_encode
 except ImportError:
     from base64 import encodestring as base64_encode
 
 import json
 import mimetypes
 import os
 import struct
+import sys
 import warnings
 
 from IPython.utils.py3compat import (string_types, cast_bytes_py2, cast_unicode,
                                      unicode_type)
 from IPython.testing.skipdoctest import skip_doctest
 
 __all__ = ['display', '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', 'JSON', 'Javascript',
 'Image', 'clear_output', 'set_matplotlib_formats', 'set_matplotlib_close',
 'publish_display_data']
 
 #-----------------------------------------------------------------------------
 # 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 _merge(d1, d2):
     """Like update, but merges sub-dicts instead of clobbering at the top level.
 
     Updates d1 in-place
     """
 
     if not isinstance(d2, dict) or not isinstance(d1, dict):
         return d2
     for key, value in d2.items():
         d1[key] = _merge(d1.get(key), value)
     return d1
 
 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 : tuple of objects
         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 publish_display_data(data, metadata=None, source=None):
     """Publish data and metadata to all frontends.
 
     See the ``display_data`` message in the messaging documentation for
     more details about this message type.
 
     The following MIME types are currently implemented:
 
     * text/plain
     * text/html
     * text/markdown
     * text/latex
     * application/json
     * application/javascript
     * image/png
     * image/jpeg
     * image/svg+xml
 
     Parameters
     ----------
     data : dict
         A dictionary having keys that are valid MIME types (like
         'text/plain' or 'image/svg+xml') and values that are the data for
         that MIME type. The data itself must be a JSON'able data
         structure. Minimally all data should have the 'text/plain' data,
         which can be displayed by all frontends. If more than the plain
         text is given, it is up to the frontend to decide which
         representation to use.
     metadata : dict
         A dictionary for metadata related to the data. This can contain
         arbitrary key, value pairs that frontends can use to interpret
         the data. mime-type keys matching those in data can be used
         to specify metadata about particular representations.
     source : str, deprecated
         Unused.
         """
     from IPython.core.interactiveshell import InteractiveShell
     InteractiveShell.instance().display_pub.publish(
         data=data,
         metadata=metadata,
     )
 
 def display(*objs, **kwargs):
     """Display a Python object in all frontends.
 
     By default all representations will be computed and sent to the frontends.
     Frontends can decide which representation is used and how.
 
     Parameters
     ----------
     objs : tuple of objects
         The Python objects to display.
     raw : bool, optional
         Are the objects to be displayed already mimetype-keyed dicts of raw display data,
         or Python objects that need to be formatted before display? [default: False]
     include : list or tuple, optional
         A list of format type strings (MIME types) to include in the
         format data dict. If this is set *only* the format types included
         in this list will be computed.
     exclude : list or tuple, optional
         A list of format type strings (MIME types) to exclude in the format
         data dict. If this is set all format types will be computed,
         except for those included in this argument.
     metadata : dict, optional
         A dictionary of metadata to associate with the output.
         mime-type keys in this dictionary will be associated with the individual
         representation formats, if they exist.
     """
     raw = kwargs.get('raw', False)
     include = kwargs.get('include')
     exclude = kwargs.get('exclude')
     metadata = kwargs.get('metadata')
 
     from IPython.core.interactiveshell import InteractiveShell
 
     if not raw:
         format = InteractiveShell.instance().display_formatter.format
 
     for obj in objs:
         if raw:
             publish_display_data(data=obj, metadata=metadata)
         else:
             format_dict, md_dict = format(obj, include=include, exclude=exclude)
             if not format_dict:
                 # nothing to display (e.g. _ipython_display_ took over)
                 continue
             if metadata:
                 # kwarg-specified metadata gets precedence
                 _merge(md_dict, metadata)
             publish_display_data(data=format_dict, metadata=md_dict)
 
 
 def display_pretty(*objs, **kwargs):
     """Display the pretty (default) representation of an object.
 
     Parameters
     ----------
     objs : tuple of objects
         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 : tuple of objects
         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 : tuple of objects
         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 : tuple of objects
         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 : tuple of objects
         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 : tuple of objects
         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 : tuple of objects
         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 : tuple of objects
         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 : tuple of objects
         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 : tuple of objects
         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
 
     def __init__(self, data=None, url=None, filename=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.
         """
         if data is not None and isinstance(data, string_types):
             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.data = data
         self.url = url
         self.filename = None if filename is None else unicode_type(filename)
 
         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 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:
             try:
                 try:
                     from urllib.request import urlopen  # Py3
                 except ImportError:
                     from urllib2 import urlopen
                 response = urlopen(self.url)
                 self.data = response.read()
                 # extract encoding from header, if there is one:
                 encoding = None
                 for sub in response.headers['content-type'].split(';'):
                     sub = sub.strip()
                     if sub.startswith('charset'):
                         encoding = sub.split('=')[-1].strip()
                         break
                 # decode data, if an encoding was specified
                 if encoding:
                     self.data = self.data.decode(encoding, 'replace')
             except:
                 self.data = None
 
 class TextDisplayObject(DisplayObject):
     """Validate that display data is text"""
     def _check_data(self):
         if self.data is not None and not isinstance(self.data, string_types):
             raise TypeError("%s expects text, not %r" % (self.__class__.__name__, self.data))
 
 class Pretty(TextDisplayObject):
 
     def _repr_pretty_(self):
         return self.data
 
 
 class HTML(TextDisplayObject):
 
     def _repr_html_(self):
         return self.data
 
     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
 
 
 class Math(TextDisplayObject):
 
     def _repr_latex_(self):
         s = self.data.strip('$')
         return "$$%s$$" % s
 
 
 class Latex(TextDisplayObject):
 
     def _repr_latex_(self):
         return self.data
 
 
 class SVG(DisplayObject):
 
     # 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
         svg = cast_bytes_py2(svg)
         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
 
 
 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 _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, string_types):
             warnings.warn("JSON expects JSONable dict or list, not JSON strings")
             data = json.loads(data)
         self._data = data
 
     def _repr_json_(self):
         return self.data
 
 css_t = """$("head").append($("<link/>").attr({
   rel:  "stylesheet",
   type: "text/css",
   href: "%s"
 }));
 """
 
 lib_t1 = """$.getScript("%s", function () {
 """
 lib_t2 = """});
 """
 
 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, string_types):
             lib = [lib]
         elif lib is None:
             lib = []
         if isinstance(css, string_types):
             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
     w4h4 = data[ihdr+4:ihdr+12]
     return struct.unpack('>ii', w4h4)
 
 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
 
 class Image(DisplayObject):
 
     _read_flags = 'rb'
     _FMT_JPEG = u'jpeg'
     _FMT_PNG = u'png'
     _ACCEPTABLE_EMBEDDINGS = [_FMT_JPEG, _FMT_PNG]
 
     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 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). 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 to which to constrain the image in html
         height : int
             Height 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 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, string_types) 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
                 if ext == u'png':
                     format = self._FMT_PNG
                 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 = 'png'
 
         if format.lower() == 'jpg':
             # jpg->jpeg
             format = self._FMT_JPEG
 
         self.format = unicode_type(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))
         self.width = width
         self.height = height
         self.retina = retina
         self.unconfined = unconfined
         self.metadata = metadata
         super(Image, self).__init__(data=data, url=url, filename=filename)
         
         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 == 'png':
             w, h = _pngxy(self.data)
         elif self.format == 'jpeg':
             w, h = _jpegxy(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 _data_and_metadata(self):
         """shortcut for returning metadata with shape information, if defined"""
         md = {}
         if self.width:
             md['width'] = self.width
         if self.height:
             md['height'] = self.height
         if self.unconfined:
             md['unconfined'] = self.unconfined
         if self.metadata:
             md.update(self.metadata)
         if md:
             return self.data, md
         else:
             return self.data
 
     def _repr_png_(self):
         if self.embed and self.format == u'png':
             return self._data_and_metadata()
 
     def _repr_jpeg_(self):
         if self.embed and (self.format == u'jpeg' or self.format == u'jpg'):
             return self._data_and_metadata()
 
     def _find_ext(self, s):
         return unicode_type(s.split('.')[-1].lower())
 
 class Video(DisplayObject):
 
     def __init__(self, data=None, url=None, filename=None, embed=False, mimetype=None):
         """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.
 
         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(b'raw-videodata', embed=True)
         """
         if url is None and isinstance(data, string_types) 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
         super(Video, self).__init__(data=data, url=url, filename=filename)
 
     def _repr_html_(self):
         # 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}" controls>
       Your browser does not support the <code>video</code> element.
     </video>""".format(url)
             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, unicode_type):
             # unicode input is already b64-encoded
             b64_video = video
         else:
             b64_video = base64_encode(video).decode('ascii').rstrip()
         
         output = """<video controls>
  <source src="data:{0};base64,{1}" type="{0}">
  Your browser does not support the video tag.
  </video>""".format(mimetype, b64_video)
         return output
 
     def reload(self):
         # TODO
         pass
 
     def _repr_png_(self):
         # TODO
         pass
     def _repr_jpeg_(self):
         # TODO
         pass
 
 def clear_output(wait=False):
     """Clear the output of the current cell receiving output.
 
     Parameters
     ----------
     wait : bool [default: false]
         Wait to clear the output until new output is available to replace it."""
     from IPython.core.interactiveshell import InteractiveShell
     if InteractiveShell.initialized():
         InteractiveShell.instance().display_pub.clear_output(wait)
     else:
-        from IPython.utils import io
-        print('\033[2K\r', file=io.stdout, end='')
-        io.stdout.flush()
-        print('\033[2K\r', file=io.stderr, end='')
-        io.stderr.flush()
+        print('\033[2K\r', end='')
+        sys.stdout.flush()
+        print('\033[2K\r', end='')
+        sys.stderr.flush()
 
 
 @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/displayhook.py

@@ -1,294 +1,293 b''
 # -*- coding: utf-8 -*-
 """Displayhook for IPython.
 
 This defines a callable class that IPython uses for `sys.displayhook`.
 """
 
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
 from __future__ import print_function
 
 import sys
 import io as _io
 import tokenize
 
 from traitlets.config.configurable import Configurable
-from IPython.utils import io
 from IPython.utils.py3compat import builtin_mod, cast_unicode_py2
 from traitlets import Instance, Float
 from warnings import warn
 
 # TODO: Move the various attributes (cache_size, [others now moved]). Some
 # of these are also attributes of InteractiveShell. They should be on ONE object
 # only and the other objects should ask that one object for their values.
 
 class DisplayHook(Configurable):
     """The custom IPython displayhook to replace sys.displayhook.
 
     This class does many things, but the basic idea is that it is a callable
     that gets called anytime user code returns a value.
     """
 
     shell = Instance('IPython.core.interactiveshell.InteractiveShellABC',
                      allow_none=True)
     exec_result = Instance('IPython.core.interactiveshell.ExecutionResult',
                            allow_none=True)
     cull_fraction = Float(0.2)
 
     def __init__(self, shell=None, cache_size=1000, **kwargs):
         super(DisplayHook, self).__init__(shell=shell, **kwargs)
         cache_size_min = 3
         if cache_size <= 0:
             self.do_full_cache = 0
             cache_size = 0
         elif cache_size < cache_size_min:
             self.do_full_cache = 0
             cache_size = 0
             warn('caching was disabled (min value for cache size is %s).' %
                  cache_size_min,level=3)
         else:
             self.do_full_cache = 1
 
         self.cache_size = cache_size
 
         # we need a reference to the user-level namespace
         self.shell = shell
         
         self._,self.__,self.___ = '','',''
 
         # these are deliberately global:
         to_user_ns = {'_':self._,'__':self.__,'___':self.___}
         self.shell.user_ns.update(to_user_ns)
 
     @property
     def prompt_count(self):
         return self.shell.execution_count
 
     #-------------------------------------------------------------------------
     # Methods used in __call__. Override these methods to modify the behavior
     # of the displayhook.
     #-------------------------------------------------------------------------
 
     def check_for_underscore(self):
         """Check if the user has set the '_' variable by hand."""
         # If something injected a '_' variable in __builtin__, delete
         # ipython's automatic one so we don't clobber that.  gettext() in
         # particular uses _, so we need to stay away from it.
         if '_' in builtin_mod.__dict__:
             try:
                 del self.shell.user_ns['_']
             except KeyError:
                 pass
 
     def quiet(self):
         """Should we silence the display hook because of ';'?"""
         # do not print output if input ends in ';'
         
         try:
             cell = cast_unicode_py2(self.shell.history_manager.input_hist_parsed[-1])
         except IndexError:
             # some uses of ipshellembed may fail here
             return False
         
         sio = _io.StringIO(cell)
         tokens = list(tokenize.generate_tokens(sio.readline))
 
         for token in reversed(tokens):
             if token[0] in (tokenize.ENDMARKER, tokenize.NL, tokenize.NEWLINE, tokenize.COMMENT):
                 continue
             if (token[0] == tokenize.OP) and (token[1] == ';'):
                 return True
             else:
                 return False
 
     def start_displayhook(self):
         """Start the displayhook, initializing resources."""
         pass
 
     def write_output_prompt(self):
         """Write the output prompt.
 
         The default implementation simply writes the prompt to
         ``io.stdout``.
         """
         # Use write, not print which adds an extra space.
-        io.stdout.write(self.shell.separate_out)
+        sys.stdout.write(self.shell.separate_out)
         outprompt = self.shell.prompt_manager.render('out')
         if self.do_full_cache:
-            io.stdout.write(outprompt)
+            sys.stdout.write(outprompt)
 
     def compute_format_data(self, result):
         """Compute format data of the object to be displayed.
 
         The format data is a generalization of the :func:`repr` of an object.
         In the default implementation the format data is a :class:`dict` of
         key value pair where the keys are valid MIME types and the values
         are JSON'able data structure containing the raw data for that MIME
         type. It is up to frontends to determine pick a MIME to to use and
         display that data in an appropriate manner.
 
         This method only computes the format data for the object and should
         NOT actually print or write that to a stream.
 
         Parameters
         ----------
         result : object
             The Python object passed to the display hook, whose format will be
             computed.
 
         Returns
         -------
         (format_dict, md_dict) : dict
             format_dict is a :class:`dict` whose keys are valid MIME types and values are
             JSON'able raw data for that MIME type. It is recommended that
             all return values of this should always include the "text/plain"
             MIME type representation of the object.
             md_dict is a :class:`dict` with the same MIME type keys
             of metadata associated with each output.
             
         """
         return self.shell.display_formatter.format(result)
 
     def write_format_data(self, format_dict, md_dict=None):
         """Write the format data dict to the frontend.
 
         This default version of this method simply writes the plain text
         representation of the object to ``io.stdout``. Subclasses should
         override this method to send the entire `format_dict` to the
         frontends.
 
         Parameters
         ----------
         format_dict : dict
             The format dict for the object passed to `sys.displayhook`.
         md_dict : dict (optional)
             The metadata dict to be associated with the display data.
         """
         if 'text/plain' not in format_dict:
             # nothing to do
             return
         # We want to print because we want to always make sure we have a
         # newline, even if all the prompt separators are ''. This is the
         # standard IPython behavior.
         result_repr = format_dict['text/plain']
         if '\n' in result_repr:
             # So that multi-line strings line up with the left column of
             # the screen, instead of having the output prompt mess up
             # their first line.
             # We use the prompt template instead of the expanded prompt
             # because the expansion may add ANSI escapes that will interfere
             # with our ability to determine whether or not we should add
             # a newline.
             prompt_template = self.shell.prompt_manager.out_template
             if prompt_template and not prompt_template.endswith('\n'):
                 # But avoid extraneous empty lines.
                 result_repr = '\n' + result_repr
 
-        print(result_repr, file=io.stdout)
+        print(result_repr)
 
     def update_user_ns(self, result):
         """Update user_ns with various things like _, __, _1, etc."""
 
         # Avoid recursive reference when displaying _oh/Out
         if result is not self.shell.user_ns['_oh']:
             if len(self.shell.user_ns['_oh']) >= self.cache_size and self.do_full_cache:
                 self.cull_cache()
             # Don't overwrite '_' and friends if '_' is in __builtin__ (otherwise
             # we cause buggy behavior for things like gettext).
 
             if '_' not in builtin_mod.__dict__:
                 self.___ = self.__
                 self.__ = self._
                 self._ = result
                 self.shell.push({'_':self._,
                                  '__':self.__,
                                 '___':self.___}, interactive=False)
 
             # hackish access to top-level  namespace to create _1,_2... dynamically
             to_main = {}
             if self.do_full_cache:
                 new_result = '_'+repr(self.prompt_count)
                 to_main[new_result] = result
                 self.shell.push(to_main, interactive=False)
                 self.shell.user_ns['_oh'][self.prompt_count] = result
 
     def fill_exec_result(self, result):
         if self.exec_result is not None:
             self.exec_result.result = result
 
     def log_output(self, format_dict):
         """Log the output."""
         if 'text/plain' not in format_dict:
             # nothing to do
             return
         if self.shell.logger.log_output:
             self.shell.logger.log_write(format_dict['text/plain'], 'output')
         self.shell.history_manager.output_hist_reprs[self.prompt_count] = \
                                                     format_dict['text/plain']
 
     def finish_displayhook(self):
         """Finish up all displayhook activities."""
-        io.stdout.write(self.shell.separate_out2)
-        io.stdout.flush()
+        sys.stdout.write(self.shell.separate_out2)
+        sys.stdout.flush()
 
     def __call__(self, result=None):
         """Printing with history cache management.
 
         This is invoked everytime the interpreter needs to print, and is
         activated by setting the variable sys.displayhook to it.
         """
         self.check_for_underscore()
         if result is not None and not self.quiet():
             self.start_displayhook()
             self.write_output_prompt()
             format_dict, md_dict = self.compute_format_data(result)
             self.update_user_ns(result)
             self.fill_exec_result(result)
             if format_dict:
                 self.write_format_data(format_dict, md_dict)
                 self.log_output(format_dict)
             self.finish_displayhook()
 
     def cull_cache(self):
         """Output cache is full, cull the oldest entries"""
         oh = self.shell.user_ns.get('_oh', {})
         sz = len(oh)
         cull_count = max(int(sz * self.cull_fraction), 2)
         warn('Output cache limit (currently {sz} entries) hit.\n'
              'Flushing oldest {cull_count} entries.'.format(sz=sz, cull_count=cull_count))
         
         for i, n in enumerate(sorted(oh)):
             if i >= cull_count:
                 break
             self.shell.user_ns.pop('_%i' % n, None)
             oh.pop(n, None)
         
 
     def flush(self):
         if not self.do_full_cache:
             raise ValueError("You shouldn't have reached the cache flush "
                              "if full caching is not enabled!")
         # delete auto-generated vars from global namespace
 
         for n in range(1,self.prompt_count + 1):
             key = '_'+repr(n)
             try:
                 del self.shell.user_ns[key]
             except: pass
         # In some embedded circumstances, the user_ns doesn't have the
         # '_oh' key set up.
         oh = self.shell.user_ns.get('_oh', None)
         if oh is not None:
             oh.clear()
 
         # Release our own references to objects:
         self._, self.__, self.___ = '', '', ''
 
         if '_' not in builtin_mod.__dict__:
             self.shell.user_ns.update({'_':None,'__':None, '___':None})
         import gc
         # TODO: Is this really needed?
         # IronPython blocks here forever
         if sys.platform != "cli":
             gc.collect()

IPython/core/displaypub.py

@@ -1,116 +1,117 b''
 """An interface for publishing rich data to frontends.
 
 There are two components of the display system:
 
 * Display formatters, which take a Python object and compute the
   representation of the object in various formats (text, HTML, SVG, etc.).
 * The display publisher that is used to send the representation data to the
   various frontends.
 
 This module defines the logic display publishing. The display publisher uses
 the ``display_data`` message type that is defined in the IPython messaging
 spec.
 """
 
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
 from __future__ import print_function
 
+import sys
+
 from traitlets.config.configurable import Configurable
-from IPython.utils import io
 from traitlets import List
 
 # This used to be defined here - it is imported for backwards compatibility
 from .display import publish_display_data
 
 #-----------------------------------------------------------------------------
 # Main payload class
 #-----------------------------------------------------------------------------
 
 class DisplayPublisher(Configurable):
     """A traited class that publishes display data to frontends.
 
     Instances of this class are created by the main IPython object and should
     be accessed there.
     """
 
     def _validate_data(self, data, metadata=None):
         """Validate the display data.
 
         Parameters
         ----------
         data : dict
             The formata data dictionary.
         metadata : dict
             Any metadata for the data.
         """
 
         if not isinstance(data, dict):
             raise TypeError('data must be a dict, got: %r' % data)
         if metadata is not None:
             if not isinstance(metadata, dict):
                 raise TypeError('metadata must be a dict, got: %r' % data)
 
     def publish(self, data, metadata=None, source=None):
         """Publish data and metadata to all frontends.
 
         See the ``display_data`` message in the messaging documentation for
         more details about this message type.
 
         The following MIME types are currently implemented:
 
         * text/plain
         * text/html
         * text/markdown
         * text/latex
         * application/json
         * application/javascript
         * image/png
         * image/jpeg
         * image/svg+xml
 
         Parameters
         ----------
         data : dict
             A dictionary having keys that are valid MIME types (like
             'text/plain' or 'image/svg+xml') and values that are the data for
             that MIME type. The data itself must be a JSON'able data
             structure. Minimally all data should have the 'text/plain' data,
             which can be displayed by all frontends. If more than the plain
             text is given, it is up to the frontend to decide which
             representation to use.
         metadata : dict
             A dictionary for metadata related to the data. This can contain
             arbitrary key, value pairs that frontends can use to interpret
             the data.  Metadata specific to each mime-type can be specified
             in the metadata dict with the same mime-type keys as
             the data itself.
         source : str, deprecated
             Unused.
         """
 
         # The default is to simply write the plain text data using io.stdout.
         if 'text/plain' in data:
-            print(data['text/plain'], file=io.stdout)
+            print(data['text/plain'])
 
     def clear_output(self, wait=False):
         """Clear the output of the cell receiving output."""
-        print('\033[2K\r', file=io.stdout, end='')
-        io.stdout.flush()
-        print('\033[2K\r', file=io.stderr, end='')
-        io.stderr.flush()
+        print('\033[2K\r', end='')
+        sys.stdout.flush()
+        print('\033[2K\r', end='')
+        sys.stderr.flush()
 
 
 class CapturingDisplayPublisher(DisplayPublisher):
     """A DisplayPublisher that stores"""
     outputs = List()
 
     def publish(self, data, metadata=None, source=None):
         self.outputs.append((data, metadata))
     
     def clear_output(self, wait=False):
         super(CapturingDisplayPublisher, self).clear_output(wait)
         
         # empty the list, *do not* reassign a new list
         del self.outputs[:]

IPython/core/magics/history.py

@@ -1,319 +1,320 b''
 """Implementation of magic functions related to History.
 """
 #-----------------------------------------------------------------------------
 #  Copyright (c) 2012, IPython Development Team.
 #
 #  Distributed under the terms of the Modified BSD License.
 #
 #  The full license is in the file COPYING.txt, distributed with this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 from __future__ import print_function
 
 # Stdlib
 import os
+import sys
 from io import open as io_open
 
 # Our own packages
 from IPython.core.error import StdinNotImplementedError
 from IPython.core.magic import Magics, magics_class, line_magic
 from IPython.core.magic_arguments import (argument, magic_arguments,
                                           parse_argstring)
 from IPython.testing.skipdoctest import skip_doctest
 from IPython.utils import io
 from IPython.utils.py3compat import cast_unicode_py2
 
 #-----------------------------------------------------------------------------
 # Magics class implementation
 #-----------------------------------------------------------------------------
 
 
 _unspecified = object()
 
 
 @magics_class
 class HistoryMagics(Magics):
 
     @magic_arguments()
     @argument(
         '-n', dest='print_nums', action='store_true', default=False,
         help="""
         print line numbers for each input.
         This feature is only available if numbered prompts are in use.
         """)
     @argument(
         '-o', dest='get_output', action='store_true', default=False,
         help="also print outputs for each input.")
     @argument(
         '-p', dest='pyprompts', action='store_true', default=False,
         help="""
         print classic '>>>' python prompts before each input.
         This is useful for making documentation, and in conjunction
         with -o, for producing doctest-ready output.
         """)
     @argument(
         '-t', dest='raw', action='store_false', default=True,
         help="""
         print the 'translated' history, as IPython understands it.
         IPython filters your input and converts it all into valid Python
         source before executing it (things like magics or aliases are turned
         into function calls, for example). With this option, you'll see the
         native history instead of the user-entered version: '%%cd /' will be
         seen as 'get_ipython().magic("%%cd /")' instead of '%%cd /'.
         """)
     @argument(
         '-f', dest='filename',
         help="""
         FILENAME: instead of printing the output to the screen, redirect
         it to the given file.  The file is always overwritten, though *when
         it can*, IPython asks for confirmation first. In particular, running
         the command 'history -f FILENAME' from the IPython Notebook
         interface will replace FILENAME even if it already exists *without*
         confirmation.
         """)
     @argument(
         '-g', dest='pattern', nargs='*', default=None,
         help="""
         treat the arg as a glob pattern to search for in (full) history.
         This includes the saved history (almost all commands ever written).
         The pattern may contain '?' to match one unknown character and '*'
         to match any number of unknown characters. Use '%%hist -g' to show
         full saved history (may be very long).
         """)
     @argument(
         '-l', dest='limit', type=int, nargs='?', default=_unspecified,
         help="""
         get the last n lines from all sessions. Specify n as a single
         arg, or the default is the last 10 lines.
         """)
     @argument(
         '-u', dest='unique', action='store_true',
         help="""
         when searching history using `-g`, show only unique history.
         """)
     @argument('range', nargs='*')
     @skip_doctest
     @line_magic
     def history(self, parameter_s = ''):
         """Print input history (_i<n> variables), with most recent last.
 
         By default, input history is printed without line numbers so it can be
         directly pasted into an editor. Use -n to show them.
 
         By default, all input history from the current session is displayed.
         Ranges of history can be indicated using the syntax:
         
         ``4``
             Line 4, current session
         ``4-6``
             Lines 4-6, current session
         ``243/1-5``
             Lines 1-5, session 243
         ``~2/7``
             Line 7, session 2 before current
         ``~8/1-~6/5``
             From the first line of 8 sessions ago, to the fifth line of 6
             sessions ago.
         
         Multiple ranges can be entered, separated by spaces
 
         The same syntax is used by %macro, %save, %edit, %rerun
 
         Examples
         --------
         ::
 
           In [6]: %history -n 4-6
           4:a = 12
           5:print a**2
           6:%history -n 4-6
 
         """
 
         args = parse_argstring(self.history, parameter_s)
 
         # For brevity
         history_manager = self.shell.history_manager
 
         def _format_lineno(session, line):
             """Helper function to format line numbers properly."""
             if session in (0, history_manager.session_number):
                 return str(line)
             return "%s/%s" % (session, line)
 
         # Check if output to specific file was requested.
         outfname = args.filename
         if not outfname:
-            outfile = io.stdout  # default
+            outfile = sys.stdout  # default
             # We don't want to close stdout at the end!
             close_at_end = False
         else:
             if os.path.exists(outfname):
                 try:
                     ans = io.ask_yes_no("File %r exists. Overwrite?" % outfname)
                 except StdinNotImplementedError:
                     ans = True
                 if not ans:
                     print('Aborting.')
                     return
                 print("Overwriting file.")
             outfile = io_open(outfname, 'w', encoding='utf-8')
             close_at_end = True
 
         print_nums = args.print_nums
         get_output = args.get_output
         pyprompts = args.pyprompts
         raw = args.raw
 
         pattern = None
         limit = None if args.limit is _unspecified else args.limit
 
         if args.pattern is not None:
             if args.pattern:
                 pattern = "*" + " ".join(args.pattern) + "*"
             else:
                 pattern = "*"
             hist = history_manager.search(pattern, raw=raw, output=get_output,
                                           n=limit, unique=args.unique)
             print_nums = True
         elif args.limit is not _unspecified:
             n = 10 if limit is None else limit
             hist = history_manager.get_tail(n, raw=raw, output=get_output)
         else:
             if args.range:      # Get history by ranges
                 hist = history_manager.get_range_by_str(" ".join(args.range),
                                                         raw, get_output)
             else:               # Just get history for the current session
                 hist = history_manager.get_range(raw=raw, output=get_output)
 
         # We could be displaying the entire history, so let's not try to pull
         # it into a list in memory. Anything that needs more space will just
         # misalign.
         width = 4
 
         for session, lineno, inline in hist:
             # Print user history with tabs expanded to 4 spaces.  The GUI
             # clients use hard tabs for easier usability in auto-indented code,
             # but we want to produce PEP-8 compliant history for safe pasting
             # into an editor.
             if get_output:
                 inline, output = inline
             inline = inline.expandtabs(4).rstrip()
 
             multiline = "\n" in inline
             line_sep = '\n' if multiline else ' '
             if print_nums:
                 print(u'%s:%s' % (_format_lineno(session, lineno).rjust(width),
                         line_sep),  file=outfile, end=u'')
             if pyprompts:
                 print(u">>> ", end=u"", file=outfile)
                 if multiline:
                     inline = "\n... ".join(inline.splitlines()) + "\n..."
             print(inline, file=outfile)
             if get_output and output:
                 print(cast_unicode_py2(output), file=outfile)
 
         if close_at_end:
             outfile.close()
 
     @line_magic
     def recall(self, arg):
         r"""Repeat a command, or get command to input line for editing.
 
         %recall and %rep are equivalent.
 
         - %recall (no arguments):
 
         Place a string version of last computation result (stored in the
         special '_' variable) to the next input prompt. Allows you to create
         elaborate command lines without using copy-paste::
 
              In[1]: l = ["hei", "vaan"]
              In[2]: "".join(l)
             Out[2]: heivaan
              In[3]: %recall
              In[4]: heivaan_ <== cursor blinking
 
         %recall 45
 
         Place history line 45 on the next input prompt. Use %hist to find
         out the number.
 
         %recall 1-4
 
         Combine the specified lines into one cell, and place it on the next
         input prompt. See %history for the slice syntax.
 
         %recall foo+bar
 
         If foo+bar can be evaluated in the user namespace, the result is
         placed at the next input prompt. Otherwise, the history is searched
         for lines which contain that substring, and the most recent one is
         placed at the next input prompt.
         """
         if not arg:                 # Last output
             self.shell.set_next_input(str(self.shell.user_ns["_"]))
             return
                                     # Get history range
         histlines = self.shell.history_manager.get_range_by_str(arg)
         cmd = "\n".join(x[2] for x in histlines)
         if cmd:
             self.shell.set_next_input(cmd.rstrip())
             return
 
         try:                        # Variable in user namespace
             cmd = str(eval(arg, self.shell.user_ns))
         except Exception:           # Search for term in history
             histlines = self.shell.history_manager.search("*"+arg+"*")
             for h in reversed([x[2] for x in histlines]):
                 if 'recall' in h or 'rep' in h:
                     continue
                 self.shell.set_next_input(h.rstrip())
                 return
         else:
             self.shell.set_next_input(cmd.rstrip())
         print("Couldn't evaluate or find in history:", arg)
 
     @line_magic
     def rerun(self, parameter_s=''):
         """Re-run previous input
 
         By default, you can specify ranges of input history to be repeated
         (as with %history). With no arguments, it will repeat the last line.
 
         Options:
 
           -l <n> : Repeat the last n lines of input, not including the
           current command.
 
           -g foo : Repeat the most recent line which contains foo
         """
         opts, args = self.parse_options(parameter_s, 'l:g:', mode='string')
         if "l" in opts:         # Last n lines
             n = int(opts['l'])
             hist = self.shell.history_manager.get_tail(n)
         elif "g" in opts:       # Search
             p = "*"+opts['g']+"*"
             hist = list(self.shell.history_manager.search(p))
             for l in reversed(hist):
                 if "rerun" not in l[2]:
                     hist = [l]     # The last match which isn't a %rerun
                     break
             else:
                 hist = []          # No matches except %rerun
         elif args:              # Specify history ranges
             hist = self.shell.history_manager.get_range_by_str(args)
         else:                   # Last line
             hist = self.shell.history_manager.get_tail(1)
         hist = [x[2] for x in hist]
         if not hist:
             print("No lines in history match specification")
             return
         histlines = "\n".join(hist)
         print("=== Executing: ===")
         print(histlines)
         print("=== Output: ===")
         self.shell.run_cell("\n".join(hist), store_history=False)

IPython/core/oinspect.py

@@ -1,929 +1,928 b''
 # -*- coding: utf-8 -*-
 """Tools for inspecting Python objects.
 
 Uses syntax highlighting for presenting the various information elements.
 
 Similar in spirit to the inspect module, but all calls take a name argument to
 reference the name under which an object is being read.
 """
 
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
 from __future__ import print_function
 
 __all__ = ['Inspector','InspectColors']
 
 # stdlib modules
 import inspect
 import linecache
 import os
 from textwrap import dedent
 import types
 import io as stdlib_io
 
 try:
     from itertools import izip_longest
 except ImportError:
     from itertools import zip_longest as izip_longest
 
 # IPython's own
 from IPython.core import page
 from IPython.lib.pretty import pretty
 from IPython.testing.skipdoctest import skip_doctest_py3
 from IPython.utils import PyColorize
-from IPython.utils import io
 from IPython.utils import openpy
 from IPython.utils import py3compat
 from IPython.utils.dir2 import safe_hasattr
 from IPython.utils.path import compress_user
 from IPython.utils.text import indent
 from IPython.utils.wildcard import list_namespace
 from IPython.utils.coloransi import TermColors, ColorScheme, ColorSchemeTable
 from IPython.utils.py3compat import cast_unicode, string_types, PY3
 from IPython.utils.signatures import signature
 from IPython.utils.colorable import Colorable
 
 # builtin docstrings to ignore
 _func_call_docstring = types.FunctionType.__call__.__doc__
 _object_init_docstring = object.__init__.__doc__
 _builtin_type_docstrings = {
     inspect.getdoc(t) for t in (types.ModuleType, types.MethodType,
                                 types.FunctionType, property)
 }
 
 _builtin_func_type = type(all)
 _builtin_meth_type = type(str.upper)  # Bound methods have the same type as builtin functions
 #****************************************************************************
 # Builtin color schemes
 
 Colors = TermColors  # just a shorthand
 
 InspectColors = PyColorize.ANSICodeColors
 
 #****************************************************************************
 # Auxiliary functions and objects
 
 # See the messaging spec for the definition of all these fields.  This list
 # effectively defines the order of display
 info_fields = ['type_name', 'base_class', 'string_form', 'namespace',
                'length', 'file', 'definition', 'docstring', 'source',
                'init_definition', 'class_docstring', 'init_docstring',
                'call_def', 'call_docstring',
                # These won't be printed but will be used to determine how to
                # format the object
                'ismagic', 'isalias', 'isclass', 'argspec', 'found', 'name'
                ]
 
 
 def object_info(**kw):
     """Make an object info dict with all fields present."""
     infodict = dict(izip_longest(info_fields, [None]))
     infodict.update(kw)
     return infodict
 
 
 def get_encoding(obj):
     """Get encoding for python source file defining obj
 
     Returns None if obj is not defined in a sourcefile.
     """
     ofile = find_file(obj)
     # run contents of file through pager starting at line where the object
     # is defined, as long as the file isn't binary and is actually on the
     # filesystem.
     if ofile is None:
         return None
     elif ofile.endswith(('.so', '.dll', '.pyd')):
         return None
     elif not os.path.isfile(ofile):
         return None
     else:
         # Print only text files, not extension binaries.  Note that
         # getsourcelines returns lineno with 1-offset and page() uses
         # 0-offset, so we must adjust.
         with stdlib_io.open(ofile, 'rb') as buffer:   # Tweaked to use io.open for Python 2
             encoding, lines = openpy.detect_encoding(buffer.readline)
         return encoding
 
 def getdoc(obj):
     """Stable wrapper around inspect.getdoc.
 
     This can't crash because of attribute problems.
 
     It also attempts to call a getdoc() method on the given object.  This
     allows objects which provide their docstrings via non-standard mechanisms
     (like Pyro proxies) to still be inspected by ipython's ? system."""
     # Allow objects to offer customized documentation via a getdoc method:
     try:
         ds = obj.getdoc()
     except Exception:
         pass
     else:
         # if we get extra info, we add it to the normal docstring.
         if isinstance(ds, string_types):
             return inspect.cleandoc(ds)
     
     try:
         docstr = inspect.getdoc(obj)
         encoding = get_encoding(obj)
         return py3compat.cast_unicode(docstr, encoding=encoding)
     except Exception:
         # Harden against an inspect failure, which can occur with
         # SWIG-wrapped extensions.
         raise
         return None
 
 
 def getsource(obj, oname=''):
     """Wrapper around inspect.getsource.
 
     This can be modified by other projects to provide customized source
     extraction.
 
     Parameters
     ----------
     obj : object
         an object whose source code we will attempt to extract
     oname : str
         (optional) a name under which the object is known
 
     Returns
     -------
     src : unicode or None
 
     """
 
     if isinstance(obj, property):
         sources = []
         for attrname in ['fget', 'fset', 'fdel']:
             fn = getattr(obj, attrname)
             if fn is not None:
                 encoding = get_encoding(fn)
                 oname_prefix = ('%s.' % oname) if oname else ''
                 sources.append(cast_unicode(
                     ''.join(('# ', oname_prefix, attrname)),
                     encoding=encoding))
                 if inspect.isfunction(fn):
                     sources.append(dedent(getsource(fn)))
                 else:
                     # Default str/repr only prints function name,
                     # pretty.pretty prints module name too.
                     sources.append(cast_unicode(
                         '%s%s = %s\n' % (
                             oname_prefix, attrname, pretty(fn)),
                         encoding=encoding))
         if sources:
             return '\n'.join(sources)
         else:
             return None
 
     else:
         # Get source for non-property objects.
 
         obj = _get_wrapped(obj)
 
         try:
             src = inspect.getsource(obj)
         except TypeError:
             # The object itself provided no meaningful source, try looking for
             # its class definition instead.
             if hasattr(obj, '__class__'):
                 try:
                     src = inspect.getsource(obj.__class__)
                 except TypeError:
                     return None
 
         encoding = get_encoding(obj)
         return cast_unicode(src, encoding=encoding)
 
 
 def is_simple_callable(obj):
     """True if obj is a function ()"""
     return (inspect.isfunction(obj) or inspect.ismethod(obj) or \
             isinstance(obj, _builtin_func_type) or isinstance(obj, _builtin_meth_type))
 
 
 def getargspec(obj):
     """Wrapper around :func:`inspect.getfullargspec` on Python 3, and
     :func:inspect.getargspec` on Python 2.
     
     In addition to functions and methods, this can also handle objects with a
     ``__call__`` attribute.
     """
     if safe_hasattr(obj, '__call__') and not is_simple_callable(obj):
         obj = obj.__call__
 
     return inspect.getfullargspec(obj) if PY3 else inspect.getargspec(obj)
 
 
 def format_argspec(argspec):
     """Format argspect, convenience wrapper around inspect's.
 
     This takes a dict instead of ordered arguments and calls
     inspect.format_argspec with the arguments in the necessary order.
     """
     return inspect.formatargspec(argspec['args'], argspec['varargs'],
                                  argspec['varkw'], argspec['defaults'])
 
 
 def call_tip(oinfo, format_call=True):
     """Extract call tip data from an oinfo dict.
 
     Parameters
     ----------
     oinfo : dict
 
     format_call : bool, optional
       If True, the call line is formatted and returned as a string.  If not, a
       tuple of (name, argspec) is returned.
 
     Returns
     -------
     call_info : None, str or (str, dict) tuple.
       When format_call is True, the whole call information is formattted as a
       single string.  Otherwise, the object's name and its argspec dict are
       returned.  If no call information is available, None is returned.
 
     docstring : str or None
       The most relevant docstring for calling purposes is returned, if
       available.  The priority is: call docstring for callable instances, then
       constructor docstring for classes, then main object's docstring otherwise
       (regular functions).
     """
     # Get call definition
     argspec = oinfo.get('argspec')
     if argspec is None:
         call_line = None
     else:
         # Callable objects will have 'self' as their first argument, prune
         # it out if it's there for clarity (since users do *not* pass an
         # extra first argument explicitly).
         try:
             has_self = argspec['args'][0] == 'self'
         except (KeyError, IndexError):
             pass
         else:
             if has_self:
                 argspec['args'] = argspec['args'][1:]
 
         call_line = oinfo['name']+format_argspec(argspec)
 
     # Now get docstring.
     # The priority is: call docstring, constructor docstring, main one.
     doc = oinfo.get('call_docstring')
     if doc is None:
         doc = oinfo.get('init_docstring')
     if doc is None:
         doc = oinfo.get('docstring','')
 
     return call_line, doc
 
 
 def _get_wrapped(obj):
     """Get the original object if wrapped in one or more @decorators
 
     Some objects automatically construct similar objects on any unrecognised
     attribute access (e.g. unittest.mock.call). To protect against infinite loops,
     this will arbitrarily cut off after 100 levels of obj.__wrapped__
     attribute access. --TK, Jan 2016
     """
     orig_obj = obj
     i = 0
     while safe_hasattr(obj, '__wrapped__'):
         obj = obj.__wrapped__
         i += 1
         if i > 100:
             # __wrapped__ is probably a lie, so return the thing we started with
             return orig_obj
     return obj
 
 def find_file(obj):
     """Find the absolute path to the file where an object was defined.
 
     This is essentially a robust wrapper around `inspect.getabsfile`.
 
     Returns None if no file can be found.
 
     Parameters
     ----------
     obj : any Python object
 
     Returns
     -------
     fname : str
       The absolute path to the file where the object was defined.
     """
     obj = _get_wrapped(obj)
 
     fname = None
     try:
         fname = inspect.getabsfile(obj)
     except TypeError:
         # For an instance, the file that matters is where its class was
         # declared.
         if hasattr(obj, '__class__'):
             try:
                 fname = inspect.getabsfile(obj.__class__)
             except TypeError:
                 # Can happen for builtins
                 pass
     except:
         pass
     return cast_unicode(fname)
 
 
 def find_source_lines(obj):
     """Find the line number in a file where an object was defined.
 
     This is essentially a robust wrapper around `inspect.getsourcelines`.
 
     Returns None if no file can be found.
 
     Parameters
     ----------
     obj : any Python object
 
     Returns
     -------
     lineno : int
       The line number where the object definition starts.
     """
     obj = _get_wrapped(obj)
     
     try:
         try:
             lineno = inspect.getsourcelines(obj)[1]
         except TypeError:
             # For instances, try the class object like getsource() does
             if hasattr(obj, '__class__'):
                 lineno = inspect.getsourcelines(obj.__class__)[1]
             else:
                 lineno = None
     except:
         return None
 
     return lineno
 
 
 class Inspector(Colorable):
     def __init__(self, color_table=InspectColors,
                  code_color_table=PyColorize.ANSICodeColors,
                  scheme='NoColor',
                  str_detail_level=0, 
                  parent=None, config=None):
         super(Inspector, self).__init__(parent=parent, config=config)
         self.color_table = color_table
         self.parser = PyColorize.Parser(out='str', parent=self, style=scheme)
         self.format = self.parser.format
         self.str_detail_level = str_detail_level
         self.set_active_scheme(scheme)
 
     def _getdef(self,obj,oname=''):
         """Return the call signature for any callable object.
 
         If any exception is generated, None is returned instead and the
         exception is suppressed."""
         try:
             hdef = oname + str(signature(obj))
             return cast_unicode(hdef)
         except:
             return None
 
     def __head(self,h):
         """Return a header string with proper colors."""
         return '%s%s%s' % (self.color_table.active_colors.header,h,
                            self.color_table.active_colors.normal)
 
     def set_active_scheme(self, scheme):
         self.color_table.set_active_scheme(scheme)
         self.parser.color_table.set_active_scheme(scheme)
 
     def noinfo(self, msg, oname):
         """Generic message when no information is found."""
         print('No %s found' % msg, end=' ')
         if oname:
             print('for %s' % oname)
         else:
             print()
 
     def pdef(self, obj, oname=''):
         """Print the call signature for any callable object.
 
         If the object is a class, print the constructor information."""
 
         if not callable(obj):
             print('Object is not callable.')
             return
 
         header = ''
 
         if inspect.isclass(obj):
             header = self.__head('Class constructor information:\n')
         elif (not py3compat.PY3) and type(obj) is types.InstanceType:
             obj = obj.__call__
 
         output = self._getdef(obj,oname)
         if output is None:
             self.noinfo('definition header',oname)
         else:
-            print(header,self.format(output), end=' ', file=io.stdout)
+            print(header,self.format(output), end=' ')
 
     # In Python 3, all classes are new-style, so they all have __init__.
     @skip_doctest_py3
     def pdoc(self,obj,oname='',formatter = None):
         """Print the docstring for any object.
 
         Optional:
         -formatter: a function to run the docstring through for specially
         formatted docstrings.
 
         Examples
         --------
 
         In [1]: class NoInit:
            ...:     pass
 
         In [2]: class NoDoc:
            ...:     def __init__(self):
            ...:         pass
 
         In [3]: %pdoc NoDoc
         No documentation found for NoDoc
 
         In [4]: %pdoc NoInit
         No documentation found for NoInit
 
         In [5]: obj = NoInit()
 
         In [6]: %pdoc obj
         No documentation found for obj
 
         In [5]: obj2 = NoDoc()
 
         In [6]: %pdoc obj2
         No documentation found for obj2
         """
 
         head = self.__head  # For convenience
         lines = []
         ds = getdoc(obj)
         if formatter:
             ds = formatter(ds)
         if ds:
             lines.append(head("Class docstring:"))
             lines.append(indent(ds))
         if inspect.isclass(obj) and hasattr(obj, '__init__'):
             init_ds = getdoc(obj.__init__)
             if init_ds is not None:
                 lines.append(head("Init docstring:"))
                 lines.append(indent(init_ds))
         elif hasattr(obj,'__call__'):
             call_ds = getdoc(obj.__call__)
             if call_ds:
                 lines.append(head("Call docstring:"))
                 lines.append(indent(call_ds))
 
         if not lines:
             self.noinfo('documentation',oname)
         else:
             page.page('\n'.join(lines))
 
     def psource(self, obj, oname=''):
         """Print the source code for an object."""
 
         # Flush the source cache because inspect can return out-of-date source
         linecache.checkcache()
         try:
             src = getsource(obj, oname=oname)
         except Exception:
             src = None
 
         if src is None:
             self.noinfo('source', oname)
         else:
             page.page(self.format(src))
 
     def pfile(self, obj, oname=''):
         """Show the whole file where an object was defined."""
         
         lineno = find_source_lines(obj)
         if lineno is None:
             self.noinfo('file', oname)
             return
 
         ofile = find_file(obj)
         # run contents of file through pager starting at line where the object
         # is defined, as long as the file isn't binary and is actually on the
         # filesystem.
         if ofile.endswith(('.so', '.dll', '.pyd')):
             print('File %r is binary, not printing.' % ofile)
         elif not os.path.isfile(ofile):
             print('File %r does not exist, not printing.' % ofile)
         else:
             # Print only text files, not extension binaries.  Note that
             # getsourcelines returns lineno with 1-offset and page() uses
             # 0-offset, so we must adjust.
             page.page(self.format(openpy.read_py_file(ofile, skip_encoding_cookie=False)), lineno - 1)
 
     def _format_fields(self, fields, title_width=0):
         """Formats a list of fields for display.
 
         Parameters
         ----------
         fields : list
           A list of 2-tuples: (field_title, field_content)
         title_width : int
           How many characters to pad titles to. Default to longest title.
         """
         out = []
         header = self.__head
         if title_width == 0:
             title_width = max(len(title) + 2 for title, _ in fields)
         for title, content in fields:
             if len(content.splitlines()) > 1:
                 title = header(title + ":") + "\n"
             else:
                 title = header((title+":").ljust(title_width))
             out.append(cast_unicode(title) + cast_unicode(content))
         return "\n".join(out)
     
     def _format_info(self, obj, oname='', formatter=None, info=None, detail_level=0):
         """Format an info dict as text"""
         info = self.info(obj, oname=oname, formatter=formatter,
                             info=info, detail_level=detail_level)
         displayfields = []
         def add_fields(fields):
             for title, key in fields:
                 field = info[key]
                 if field is not None:
                     if key == "source":
                         displayfields.append((title, self.format(cast_unicode(field.rstrip()))))
                     else:
                         displayfields.append((title, field.rstrip()))
 
         if info['isalias']:
             add_fields([('Repr', "string_form")])
 
         elif info['ismagic']:
             if detail_level > 0 and info['source'] is not None:
                 add_fields([("Source", "source")])
             else:
                 add_fields([("Docstring", "docstring")])
 
             add_fields([("File", "file"),
                        ])
 
         elif info['isclass'] or is_simple_callable(obj):
             # Functions, methods, classes
             add_fields([("Signature", "definition"),
                         ("Init signature", "init_definition"),
                        ])
             if detail_level > 0 and info['source'] is not None:
                 add_fields([("Source", "source")])
             else:
                 add_fields([("Docstring", "docstring"),
                             ("Init docstring", "init_docstring"),
                            ])
 
             add_fields([('File', 'file'),
                         ('Type', 'type_name'),
                        ])
 
         else:
             # General Python objects
             add_fields([("Type", "type_name")])
 
             # Base class for old-style instances
             if (not py3compat.PY3) and isinstance(obj, types.InstanceType) and info['base_class']:
                 displayfields.append(("Base Class", info['base_class'].rstrip()))
 
             add_fields([("String form", "string_form")])
 
             # Namespace
             if info['namespace'] != 'Interactive':
                 displayfields.append(("Namespace", info['namespace'].rstrip()))
 
             add_fields([("Length", "length"),
                         ("File", "file"),
                         ("Signature", "definition"),
                        ])
 
             # Source or docstring, depending on detail level and whether
             # source found.
             if detail_level > 0 and info['source'] is not None:
                 displayfields.append(("Source",
                                       self.format(cast_unicode(info['source']))))
             elif info['docstring'] is not None:
                 displayfields.append(("Docstring", info["docstring"]))
 
             add_fields([("Class docstring", "class_docstring"),
                         ("Init docstring", "init_docstring"),
                         ("Call signature", "call_def"),
                         ("Call docstring", "call_docstring")])
         
         if displayfields:
             return self._format_fields(displayfields)
         else:
             return u''
     
     def pinfo(self, obj, oname='', formatter=None, info=None, detail_level=0):
         """Show detailed information about an object.
 
         Optional arguments:
 
         - oname: name of the variable pointing to the object.
 
         - formatter: special formatter for docstrings (see pdoc)
 
         - info: a structure with some information fields which may have been
           precomputed already.
 
         - detail_level: if set to 1, more information is given.
         """
         text = self._format_info(obj, oname, formatter, info, detail_level)
         if text:
             page.page(text)
     
     def info(self, obj, oname='', formatter=None, info=None, detail_level=0):
         """Compute a dict with detailed information about an object.
 
         Optional arguments:
 
         - oname: name of the variable pointing to the object.
 
         - formatter: special formatter for docstrings (see pdoc)
 
         - info: a structure with some information fields which may have been
           precomputed already.
 
         - detail_level: if set to 1, more information is given.
         """
 
         obj_type = type(obj)
 
         if info is None:
             ismagic = 0
             isalias = 0
             ospace = ''
         else:
             ismagic = info.ismagic
             isalias = info.isalias
             ospace = info.namespace
 
         # Get docstring, special-casing aliases:
         if isalias:
             if not callable(obj):
                 try:
                     ds = "Alias to the system command:\n  %s" % obj[1]
                 except:
                     ds = "Alias: " + str(obj)
             else:
                 ds = "Alias to " + str(obj)
                 if obj.__doc__:
                     ds += "\nDocstring:\n" + obj.__doc__
         else:
             ds = getdoc(obj)
             if ds is None:
                 ds = '<no docstring>'
         if formatter is not None:
             ds = formatter(ds)
 
         # store output in a dict, we initialize it here and fill it as we go
         out = dict(name=oname, found=True, isalias=isalias, ismagic=ismagic)
 
         string_max = 200 # max size of strings to show (snipped if longer)
         shalf = int((string_max -5)/2)
 
         if ismagic:
             obj_type_name = 'Magic function'
         elif isalias:
             obj_type_name = 'System alias'
         else:
             obj_type_name = obj_type.__name__
         out['type_name'] = obj_type_name
 
         try:
             bclass = obj.__class__
             out['base_class'] = str(bclass)
         except: pass
 
         # String form, but snip if too long in ? form (full in ??)
         if detail_level >= self.str_detail_level:
             try:
                 ostr = str(obj)
                 str_head = 'string_form'
                 if not detail_level and len(ostr)>string_max:
                     ostr = ostr[:shalf] + ' <...> ' + ostr[-shalf:]
                     ostr = ("\n" + " " * len(str_head.expandtabs())).\
                             join(q.strip() for q in ostr.split("\n"))
                 out[str_head] = ostr
             except:
                 pass
 
         if ospace:
             out['namespace'] = ospace
 
         # Length (for strings and lists)
         try:
             out['length'] = str(len(obj))
         except: pass
 
         # Filename where object was defined
         binary_file = False
         fname = find_file(obj)
         if fname is None:
             # if anything goes wrong, we don't want to show source, so it's as
             # if the file was binary
             binary_file = True
         else:
             if fname.endswith(('.so', '.dll', '.pyd')):
                 binary_file = True
             elif fname.endswith('<string>'):
                 fname = 'Dynamically generated function. No source code available.'
             out['file'] = compress_user(fname)
 
         # Original source code for a callable, class or property.
         if detail_level:
             # Flush the source cache because inspect can return out-of-date
             # source
             linecache.checkcache()
             try:
                 if isinstance(obj, property) or not binary_file:
                     src = getsource(obj, oname)
                     if src is not None:
                         src = src.rstrip()
                     out['source'] = src
 
             except Exception:
                 pass
 
         # Add docstring only if no source is to be shown (avoid repetitions).
         if ds and out.get('source', None) is None:
             out['docstring'] = ds
 
         # Constructor docstring for classes
         if inspect.isclass(obj):
             out['isclass'] = True
 
             # get the init signature:
             try:
                 init_def = self._getdef(obj, oname)
             except AttributeError:
                 init_def = None
 
             if init_def:
                 out['init_definition'] = self.format(init_def)
 
             # get the __init__ docstring
             try:
                 obj_init = obj.__init__
             except AttributeError:
                 init_ds = None
             else:
                 init_ds = getdoc(obj_init)
                 # Skip Python's auto-generated docstrings
                 if init_ds == _object_init_docstring:
                     init_ds = None
 
             if init_ds:
                 out['init_docstring'] = init_ds
 
         # and class docstring for instances:
         else:
             # reconstruct the function definition and print it:
             defln = self._getdef(obj, oname)
             if defln:
                 out['definition'] = self.format(defln)
 
             # First, check whether the instance docstring is identical to the
             # class one, and print it separately if they don't coincide.  In
             # most cases they will, but it's nice to print all the info for
             # objects which use instance-customized docstrings.
             if ds:
                 try:
                     cls = getattr(obj,'__class__')
                 except:
                     class_ds = None
                 else:
                     class_ds = getdoc(cls)
                 # Skip Python's auto-generated docstrings
                 if class_ds in _builtin_type_docstrings:
                     class_ds = None
                 if class_ds and ds != class_ds:
                     out['class_docstring'] = class_ds
 
             # Next, try to show constructor docstrings
             try:
                 init_ds = getdoc(obj.__init__)
                 # Skip Python's auto-generated docstrings
                 if init_ds == _object_init_docstring:
                     init_ds = None
             except AttributeError:
                 init_ds = None
             if init_ds:
                 out['init_docstring'] = init_ds
 
             # Call form docstring for callable instances
             if safe_hasattr(obj, '__call__') and not is_simple_callable(obj):
                 call_def = self._getdef(obj.__call__, oname)
                 if call_def:
                     call_def = self.format(call_def)
                     # it may never be the case that call def and definition differ,
                     # but don't include the same signature twice
                     if call_def != out.get('definition'):
                         out['call_def'] = call_def
                 call_ds = getdoc(obj.__call__)
                 # Skip Python's auto-generated docstrings
                 if call_ds == _func_call_docstring:
                     call_ds = None
                 if call_ds:
                     out['call_docstring'] = call_ds
 
         # Compute the object's argspec as a callable.  The key is to decide
         # whether to pull it from the object itself, from its __init__ or
         # from its __call__ method.
 
         if inspect.isclass(obj):
             # Old-style classes need not have an __init__
             callable_obj = getattr(obj, "__init__", None)
         elif callable(obj):
             callable_obj = obj
         else:
             callable_obj = None
 
         if callable_obj is not None:
             try:
                 argspec = getargspec(callable_obj)
             except (TypeError, AttributeError):
                 # For extensions/builtins we can't retrieve the argspec
                 pass
             else:
                 # named tuples' _asdict() method returns an OrderedDict, but we
                 # we want a normal
                 out['argspec'] = argspec_dict = dict(argspec._asdict())
                 # We called this varkw before argspec became a named tuple.
                 # With getfullargspec it's also called varkw.
                 if 'varkw' not in argspec_dict:
                     argspec_dict['varkw'] = argspec_dict.pop('keywords')
 
         return object_info(**out)
 
     def psearch(self,pattern,ns_table,ns_search=[],
                 ignore_case=False,show_all=False):
         """Search namespaces with wildcards for objects.
 
         Arguments:
 
         - pattern: string containing shell-like wildcards to use in namespace
           searches and optionally a type specification to narrow the search to
           objects of that type.
 
         - ns_table: dict of name->namespaces for search.
 
         Optional arguments:
 
           - ns_search: list of namespace names to include in search.
 
           - ignore_case(False): make the search case-insensitive.
 
           - show_all(False): show all names, including those starting with
             underscores.
         """
         #print 'ps pattern:<%r>' % pattern # dbg
 
         # defaults
         type_pattern = 'all'
         filter = ''
 
         cmds = pattern.split()
         len_cmds  =  len(cmds)
         if len_cmds == 1:
             # Only filter pattern given
             filter = cmds[0]
         elif len_cmds == 2:
             # Both filter and type specified
             filter,type_pattern = cmds
         else:
             raise ValueError('invalid argument string for psearch: <%s>' %
                              pattern)
 
         # filter search namespaces
         for name in ns_search:
             if name not in ns_table:
                 raise ValueError('invalid namespace <%s>. Valid names: %s' %
                                  (name,ns_table.keys()))
 
         #print 'type_pattern:',type_pattern # dbg
         search_result, namespaces_seen = set(), set()
         for ns_name in ns_search:
             ns = ns_table[ns_name]
             # Normally, locals and globals are the same, so we just check one.
             if id(ns) in namespaces_seen:
                 continue
             namespaces_seen.add(id(ns))
             tmp_res = list_namespace(ns, type_pattern, filter,
                                     ignore_case=ignore_case, show_all=show_all)
             search_result.update(tmp_res)
 
         page.page('\n'.join(sorted(search_result)))

IPython/core/page.py

@@ -1,385 +1,384 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.
 
 from __future__ import print_function
 
 import os
 import re
 import sys
 import tempfile
 
 from io import UnsupportedOperation
 
 from IPython import get_ipython
 from IPython.core.display import display
 from IPython.core.error import TryNext
 from IPython.utils.data import chop
-from IPython.utils import io
 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."""
 
     out_ln  = strng.splitlines()[start:]
     screens = chop(out_ln,screen_lines-1)
     if len(screens) == 1:
-        print(os.linesep.join(screens[0]), file=io.stdout)
+        print(os.linesep.join(screens[0]))
     else:
         last_escape = ""
         for scr in screens[0:-1]:
             hunk = os.linesep.join(scr)
-            print(last_escape + hunk, file=io.stdout)
+            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]), file=io.stdout)
+        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 everytime 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))
 
     # Curses modifies the stdout buffer size by default, which messes
     # up Python's normal stdout buffering.  This would manifest itself
     # to IPython users as delayed printing on stdout after having used
     # the pager.
     #
     # We can prevent this by manually setting the NCURSES_NO_SETBUF
     # environment variable.  For more details, see:
     # http://bugs.python.org/issue10144
     NCURSES_NO_SETBUF = os.environ.get('NCURSES_NO_SETBUF', None)
     os.environ['NCURSES_NO_SETBUF'] = ''
 
     # Proceed with curses initialization
     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 environment
     if NCURSES_NO_SETBUF is None:
         del os.environ['NCURSES_NO_SETBUF']
     else:
         os.environ['NCURSES_NO_SETBUF'] = NCURSES_NO_SETBUF
 
     # 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, file=io.stdout)
+            print(str_toprint)
             return
 
     #print 'numlines',numlines,'screenlines',screen_lines  # dbg
     if numlines <= screen_lines :
         #print '*** normal print'  # dbg
-        print(str_toprint, file=io.stdout)
+        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
                 # if I use popen4, things hang. No idea why.
                 #pager,shell_out = os.popen4(pager_cmd)
                 pager = os.popen(pager_cmd, 'w')
                 try:
                     pager_encoding = pager.encoding or sys.stdout.encoding
                     pager.write(py3compat.cast_bytes_py2(
                         strng, encoding=pager_encoding))
                 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', ''):
         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
         """
-        io.stdout.write('---Return to continue, q to quit--- ')
+        sys.stdout.write('---Return to continue, q to quit--- ')
         ans = msvcrt.getwch()
         if ans in ("q", "Q"):
             result = False
         else:
             result = True
-        io.stdout.write("\b"*37 + " "*37 + "\b"*37)
+        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
 
 
 def snip_print(str,width = 75,print_full = 0,header = ''):
     """Print a string snipping the midsection to fit in width.
 
     print_full: mode control:
     
       - 0: only snip long strings
       - 1: send to page() directly.
       - 2: snip long strings and ask for full length viewing with page()
     
     Return 1 if snipping was necessary, 0 otherwise."""
 
     if print_full == 1:
         page(header+str)
         return 0
 
     print(header, end=' ')
     if len(str) < width:
         print(str)
         snip = 0
     else:
         whalf = int((width -5)/2)
         print(str[:whalf] + ' <...> ' + str[-whalf:])
         snip = 1
     if snip and print_full == 2:
         if py3compat.input(header+' Snipped. View (y/n)? [N]').lower() == 'y':
             page(str)
     return snip

IPython/core/tests/test_interactiveshell.py

@@ -1,943 +1,929 b''
 # -*- coding: utf-8 -*-
 """Tests for the key interactiveshell module.
 
 Historically the main classes in interactiveshell have been under-tested.  This
 module should grow as many single-method tests as possible to trap many of the
 recurring bugs we seem to encounter with high-level interaction.
 """
 
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
 import ast
 import os
 import signal
 import shutil
 import sys
 import tempfile
 import unittest
 try:
     from unittest import mock
 except ImportError:
     import mock
 from os.path import join
 
 import nose.tools as nt
 
 from IPython.core.error import InputRejected
 from IPython.core.inputtransformer import InputTransformer
 from IPython.testing.decorators import (
     skipif, skip_win32, onlyif_unicode_paths, onlyif_cmds_exist,
 )
 from IPython.testing import tools as tt
 from IPython.utils.process import find_cmd
 from IPython.utils import py3compat
 from IPython.utils.py3compat import unicode_type, PY3
 
 if PY3:
     from io import StringIO
 else:
     from StringIO import StringIO
 
 #-----------------------------------------------------------------------------
 # Globals
 #-----------------------------------------------------------------------------
 # This is used by every single test, no point repeating it ad nauseam
 ip = get_ipython()
 
 #-----------------------------------------------------------------------------
 # Tests
 #-----------------------------------------------------------------------------
 
 class DerivedInterrupt(KeyboardInterrupt):
     pass
 
 class InteractiveShellTestCase(unittest.TestCase):
     def test_naked_string_cells(self):
         """Test that cells with only naked strings are fully executed"""
         # First, single-line inputs
         ip.run_cell('"a"\n')
         self.assertEqual(ip.user_ns['_'], 'a')
         # And also multi-line cells
         ip.run_cell('"""a\nb"""\n')
         self.assertEqual(ip.user_ns['_'], 'a\nb')
 
     def test_run_empty_cell(self):
         """Just make sure we don't get a horrible error with a blank
         cell of input. Yes, I did overlook that."""
         old_xc = ip.execution_count
         res = ip.run_cell('')
         self.assertEqual(ip.execution_count, old_xc)
         self.assertEqual(res.execution_count, None)
 
     def test_run_cell_multiline(self):
         """Multi-block, multi-line cells must execute correctly.
         """
         src = '\n'.join(["x=1",
                          "y=2",
                          "if 1:",
                          "    x += 1",
                          "    y += 1",])
         res = ip.run_cell(src)
         self.assertEqual(ip.user_ns['x'], 2)
         self.assertEqual(ip.user_ns['y'], 3)
         self.assertEqual(res.success, True)
         self.assertEqual(res.result, None)
 
     def test_multiline_string_cells(self):
         "Code sprinkled with multiline strings should execute (GH-306)"
         ip.run_cell('tmp=0')
         self.assertEqual(ip.user_ns['tmp'], 0)
         res = ip.run_cell('tmp=1;"""a\nb"""\n')
         self.assertEqual(ip.user_ns['tmp'], 1)
         self.assertEqual(res.success, True)
         self.assertEqual(res.result, "a\nb")
 
     def test_dont_cache_with_semicolon(self):
         "Ending a line with semicolon should not cache the returned object (GH-307)"
         oldlen = len(ip.user_ns['Out'])
         for cell in ['1;', '1;1;']:
             res = ip.run_cell(cell, store_history=True)
             newlen = len(ip.user_ns['Out'])
             self.assertEqual(oldlen, newlen)
             self.assertIsNone(res.result)
         i = 0
         #also test the default caching behavior
         for cell in ['1', '1;1']:
             ip.run_cell(cell, store_history=True)
             newlen = len(ip.user_ns['Out'])
             i += 1
             self.assertEqual(oldlen+i, newlen)
 
     def test_syntax_error(self):
         res = ip.run_cell("raise = 3")
         self.assertIsInstance(res.error_before_exec, SyntaxError)
 
     def test_In_variable(self):
         "Verify that In variable grows with user input (GH-284)"
         oldlen = len(ip.user_ns['In'])
         ip.run_cell('1;', store_history=True)
         newlen = len(ip.user_ns['In'])
         self.assertEqual(oldlen+1, newlen)
         self.assertEqual(ip.user_ns['In'][-1],'1;')
         
     def test_magic_names_in_string(self):
         ip.run_cell('a = """\n%exit\n"""')
         self.assertEqual(ip.user_ns['a'], '\n%exit\n')
     
     def test_trailing_newline(self):
         """test that running !(command) does not raise a SyntaxError"""
         ip.run_cell('!(true)\n', False)
         ip.run_cell('!(true)\n\n\n', False)
     
     def test_gh_597(self):
         """Pretty-printing lists of objects with non-ascii reprs may cause
         problems."""
         class Spam(object):
           def __repr__(self):
             return "\xe9"*50
         import IPython.core.formatters
         f = IPython.core.formatters.PlainTextFormatter()
         f([Spam(),Spam()])
     
 
     def test_future_flags(self):
         """Check that future flags are used for parsing code (gh-777)"""
         ip.run_cell('from __future__ import print_function')
         try:
             ip.run_cell('prfunc_return_val = print(1,2, sep=" ")')
             assert 'prfunc_return_val' in ip.user_ns
         finally:
             # Reset compiler flags so we don't mess up other tests.
             ip.compile.reset_compiler_flags()
 
     def test_future_unicode(self):
         """Check that unicode_literals is imported from __future__ (gh #786)"""
         try:
             ip.run_cell(u'byte_str = "a"')
             assert isinstance(ip.user_ns['byte_str'], str) # string literals are byte strings by default
             ip.run_cell('from __future__ import unicode_literals')
             ip.run_cell(u'unicode_str = "a"')
             assert isinstance(ip.user_ns['unicode_str'], unicode_type) # strings literals are now unicode
         finally:
             # Reset compiler flags so we don't mess up other tests.
             ip.compile.reset_compiler_flags()
     
     def test_can_pickle(self):
         "Can we pickle objects defined interactively (GH-29)"
         ip = get_ipython()
         ip.reset()
         ip.run_cell(("class Mylist(list):\n"
                      "    def __init__(self,x=[]):\n"
                      "        list.__init__(self,x)"))
         ip.run_cell("w=Mylist([1,2,3])")
         
         from pickle import dumps
         
         # We need to swap in our main module - this is only necessary
         # inside the test framework, because IPython puts the interactive module
         # in place (but the test framework undoes this).
         _main = sys.modules['__main__']
         sys.modules['__main__'] = ip.user_module
         try:
             res = dumps(ip.user_ns["w"])
         finally:
             sys.modules['__main__'] = _main
         self.assertTrue(isinstance(res, bytes))
         
     def test_global_ns(self):
         "Code in functions must be able to access variables outside them."
         ip = get_ipython()
         ip.run_cell("a = 10")
         ip.run_cell(("def f(x):\n"
                      "    return x + a"))
         ip.run_cell("b = f(12)")
         self.assertEqual(ip.user_ns["b"], 22)
 
     def test_bad_custom_tb(self):
         """Check that InteractiveShell is protected from bad custom exception handlers"""
-        from IPython.utils import io
-        save_stderr = io.stderr
-        try:
-            # capture stderr
-            io.stderr = StringIO()
-            ip.set_custom_exc((IOError,), lambda etype,value,tb: 1/0)
-            self.assertEqual(ip.custom_exceptions, (IOError,))
+        ip.set_custom_exc((IOError,), lambda etype,value,tb: 1/0)
+        self.assertEqual(ip.custom_exceptions, (IOError,))
+        with tt.AssertPrints("Custom TB Handler failed", channel='stderr'):
             ip.run_cell(u'raise IOError("foo")')
-            self.assertEqual(ip.custom_exceptions, ())
-            self.assertTrue("Custom TB Handler failed" in io.stderr.getvalue())
-        finally:
-            io.stderr = save_stderr
+        self.assertEqual(ip.custom_exceptions, ())
 
     def test_bad_custom_tb_return(self):
         """Check that InteractiveShell is protected from bad return types in custom exception handlers"""
-        from IPython.utils import io
-        save_stderr = io.stderr
-        try:
-            # capture stderr
-            io.stderr = StringIO()
-            ip.set_custom_exc((NameError,),lambda etype,value,tb, tb_offset=None: 1)
-            self.assertEqual(ip.custom_exceptions, (NameError,))
+        ip.set_custom_exc((NameError,),lambda etype,value,tb, tb_offset=None: 1)
+        self.assertEqual(ip.custom_exceptions, (NameError,))
+        with tt.AssertPrints("Custom TB Handler failed", channel='stderr'):
             ip.run_cell(u'a=abracadabra')
-            self.assertEqual(ip.custom_exceptions, ())
-            self.assertTrue("Custom TB Handler failed" in io.stderr.getvalue())
-        finally:
-            io.stderr = save_stderr
+        self.assertEqual(ip.custom_exceptions, ())
 
     def test_drop_by_id(self):
         myvars = {"a":object(), "b":object(), "c": object()}
         ip.push(myvars, interactive=False)
         for name in myvars:
             assert name in ip.user_ns, name
             assert name in ip.user_ns_hidden, name
         ip.user_ns['b'] = 12
         ip.drop_by_id(myvars)
         for name in ["a", "c"]:
             assert name not in ip.user_ns, name
             assert name not in ip.user_ns_hidden, name
         assert ip.user_ns['b'] == 12
         ip.reset()
 
     def test_var_expand(self):
         ip.user_ns['f'] = u'Ca\xf1o'
         self.assertEqual(ip.var_expand(u'echo $f'), u'echo Ca\xf1o')
         self.assertEqual(ip.var_expand(u'echo {f}'), u'echo Ca\xf1o')
         self.assertEqual(ip.var_expand(u'echo {f[:-1]}'), u'echo Ca\xf1')
         self.assertEqual(ip.var_expand(u'echo {1*2}'), u'echo 2')
 
         ip.user_ns['f'] = b'Ca\xc3\xb1o'
         # This should not raise any exception:
         ip.var_expand(u'echo $f')
     
     def test_var_expand_local(self):
         """Test local variable expansion in !system and %magic calls"""
         # !system
         ip.run_cell('def test():\n'
                     '    lvar = "ttt"\n'
                     '    ret = !echo {lvar}\n'
                     '    return ret[0]\n')
         res = ip.user_ns['test']()
         nt.assert_in('ttt', res)
         
         # %magic
         ip.run_cell('def makemacro():\n'
                     '    macroname = "macro_var_expand_locals"\n'
                     '    %macro {macroname} codestr\n')
         ip.user_ns['codestr'] = "str(12)"
         ip.run_cell('makemacro()')
         nt.assert_in('macro_var_expand_locals', ip.user_ns)
     
     def test_var_expand_self(self):
         """Test variable expansion with the name 'self', which was failing.
         
         See https://github.com/ipython/ipython/issues/1878#issuecomment-7698218
         """
         ip.run_cell('class cTest:\n'
                     '  classvar="see me"\n'
                     '  def test(self):\n'
                     '    res = !echo Variable: {self.classvar}\n'
                     '    return res[0]\n')
         nt.assert_in('see me', ip.user_ns['cTest']().test())
     
     def test_bad_var_expand(self):
         """var_expand on invalid formats shouldn't raise"""
         # SyntaxError
         self.assertEqual(ip.var_expand(u"{'a':5}"), u"{'a':5}")
         # NameError
         self.assertEqual(ip.var_expand(u"{asdf}"), u"{asdf}")
         # ZeroDivisionError
         self.assertEqual(ip.var_expand(u"{1/0}"), u"{1/0}")
     
     def test_silent_postexec(self):
         """run_cell(silent=True) doesn't invoke pre/post_run_cell callbacks"""
         pre_explicit = mock.Mock()
         pre_always = mock.Mock()
         post_explicit = mock.Mock()
         post_always = mock.Mock()
         
         ip.events.register('pre_run_cell', pre_explicit)
         ip.events.register('pre_execute', pre_always)
         ip.events.register('post_run_cell', post_explicit)
         ip.events.register('post_execute', post_always)
         
         try:
             ip.run_cell("1", silent=True)
             assert pre_always.called
             assert not pre_explicit.called
             assert post_always.called
             assert not post_explicit.called
             # double-check that non-silent exec did what we expected
             # silent to avoid
             ip.run_cell("1")
             assert pre_explicit.called
             assert post_explicit.called
         finally:
             # remove post-exec
             ip.events.unregister('pre_run_cell', pre_explicit)
             ip.events.unregister('pre_execute', pre_always)
             ip.events.unregister('post_run_cell', post_explicit)
             ip.events.unregister('post_execute', post_always)
     
     def test_silent_noadvance(self):
         """run_cell(silent=True) doesn't advance execution_count"""
         ec = ip.execution_count
         # silent should force store_history=False
         ip.run_cell("1", store_history=True, silent=True)
         
         self.assertEqual(ec, ip.execution_count)
         # double-check that non-silent exec did what we expected
         # silent to avoid
         ip.run_cell("1", store_history=True)
         self.assertEqual(ec+1, ip.execution_count)
     
     def test_silent_nodisplayhook(self):
         """run_cell(silent=True) doesn't trigger displayhook"""
         d = dict(called=False)
         
         trap = ip.display_trap
         save_hook = trap.hook
         
         def failing_hook(*args, **kwargs):
             d['called'] = True
         
         try:
             trap.hook = failing_hook
             res = ip.run_cell("1", silent=True)
             self.assertFalse(d['called'])
             self.assertIsNone(res.result)
             # double-check that non-silent exec did what we expected
             # silent to avoid
             ip.run_cell("1")
             self.assertTrue(d['called'])
         finally:
             trap.hook = save_hook
 
     @skipif(sys.version_info[0] >= 3, "softspace removed in py3")
     def test_print_softspace(self):
         """Verify that softspace is handled correctly when executing multiple
         statements.
 
         In [1]: print 1; print 2
         1
         2
 
         In [2]: print 1,; print 2
         1 2
         """
         
     def test_ofind_line_magic(self):
         from IPython.core.magic import register_line_magic
         
         @register_line_magic
         def lmagic(line):
             "A line magic"
 
         # Get info on line magic
         lfind = ip._ofind('lmagic')
         info = dict(found=True, isalias=False, ismagic=True,
                     namespace = 'IPython internal', obj= lmagic.__wrapped__,
                     parent = None)
         nt.assert_equal(lfind, info)
         
     def test_ofind_cell_magic(self):
         from IPython.core.magic import register_cell_magic
         
         @register_cell_magic
         def cmagic(line, cell):
             "A cell magic"
 
         # Get info on cell magic
         find = ip._ofind('cmagic')
         info = dict(found=True, isalias=False, ismagic=True,
                     namespace = 'IPython internal', obj= cmagic.__wrapped__,
                     parent = None)
         nt.assert_equal(find, info)
 
     def test_ofind_property_with_error(self):
         class A(object):
             @property
             def foo(self):
                 raise NotImplementedError()
         a = A()
 
         found = ip._ofind('a.foo', [('locals', locals())])
         info = dict(found=True, isalias=False, ismagic=False,
                     namespace='locals', obj=A.foo, parent=a)
         nt.assert_equal(found, info)
 
     def test_ofind_multiple_attribute_lookups(self):
         class A(object):
             @property
             def foo(self):
                 raise NotImplementedError()
 
         a = A()
         a.a = A()
         a.a.a = A()
 
         found = ip._ofind('a.a.a.foo', [('locals', locals())])
         info = dict(found=True, isalias=False, ismagic=False,
                     namespace='locals', obj=A.foo, parent=a.a.a)
         nt.assert_equal(found, info)
 
     def test_ofind_slotted_attributes(self):
         class A(object):
             __slots__ = ['foo']
             def __init__(self):
                 self.foo = 'bar'
 
         a = A()
         found = ip._ofind('a.foo', [('locals', locals())])
         info = dict(found=True, isalias=False, ismagic=False,
                     namespace='locals', obj=a.foo, parent=a)
         nt.assert_equal(found, info)
 
         found = ip._ofind('a.bar', [('locals', locals())])
         info = dict(found=False, isalias=False, ismagic=False,
                     namespace=None, obj=None, parent=a)
         nt.assert_equal(found, info)
 
     def test_ofind_prefers_property_to_instance_level_attribute(self):
         class A(object):
             @property
             def foo(self):
                 return 'bar'
         a = A()
         a.__dict__['foo'] = 'baz'
         nt.assert_equal(a.foo, 'bar')
         found = ip._ofind('a.foo', [('locals', locals())])
         nt.assert_is(found['obj'], A.foo)
 
     def test_custom_exception(self):
         called = []
         def my_handler(shell, etype, value, tb, tb_offset=None):
             called.append(etype)
             shell.showtraceback((etype, value, tb), tb_offset=tb_offset)
         
         ip.set_custom_exc((ValueError,), my_handler)
         try:
             res = ip.run_cell("raise ValueError('test')")
             # Check that this was called, and only once.
             self.assertEqual(called, [ValueError])
             # Check that the error is on the result object
             self.assertIsInstance(res.error_in_exec, ValueError)
         finally:
             # Reset the custom exception hook
             ip.set_custom_exc((), None)
     
     @skipif(sys.version_info[0] >= 3, "no differences with __future__ in py3")
     def test_future_environment(self):
         "Can we run code with & without the shell's __future__ imports?"
         ip.run_cell("from __future__ import division")
         ip.run_cell("a = 1/2", shell_futures=True)
         self.assertEqual(ip.user_ns['a'], 0.5)
         ip.run_cell("b = 1/2", shell_futures=False)
         self.assertEqual(ip.user_ns['b'], 0)
         
         ip.compile.reset_compiler_flags()
         # This shouldn't leak to the shell's compiler
         ip.run_cell("from __future__ import division \nc=1/2", shell_futures=False)
         self.assertEqual(ip.user_ns['c'], 0.5)
         ip.run_cell("d = 1/2", shell_futures=True)
         self.assertEqual(ip.user_ns['d'], 0)
 
     def test_mktempfile(self):
         filename = ip.mktempfile()
         # Check that we can open the file again on Windows
         with open(filename, 'w') as f:
             f.write('abc')
 
         filename = ip.mktempfile(data='blah')
         with open(filename, 'r') as f:
             self.assertEqual(f.read(), 'blah')
 
     def test_new_main_mod(self):
         # Smoketest to check that this accepts a unicode module name
         name = u'jiefmw'
         mod = ip.new_main_mod(u'%s.py' % name, name)
         self.assertEqual(mod.__name__, name)
 
     def test_get_exception_only(self):
         try:
             raise KeyboardInterrupt
         except KeyboardInterrupt:
             msg = ip.get_exception_only()
         self.assertEqual(msg, 'KeyboardInterrupt\n')
 
         try:
             raise DerivedInterrupt("foo")
         except KeyboardInterrupt:
             msg = ip.get_exception_only()
         if sys.version_info[0] <= 2:
             self.assertEqual(msg, 'DerivedInterrupt: foo\n')
         else:
             self.assertEqual(msg, 'IPython.core.tests.test_interactiveshell.DerivedInterrupt: foo\n')
 
 class TestSafeExecfileNonAsciiPath(unittest.TestCase):
 
     @onlyif_unicode_paths
     def setUp(self):
         self.BASETESTDIR = tempfile.mkdtemp()
         self.TESTDIR = join(self.BASETESTDIR, u"åäö")
         os.mkdir(self.TESTDIR)
         with open(join(self.TESTDIR, u"åäötestscript.py"), "w") as sfile:
             sfile.write("pass\n")
         self.oldpath = py3compat.getcwd()
         os.chdir(self.TESTDIR)
         self.fname = u"åäötestscript.py"
 
     def tearDown(self):
         os.chdir(self.oldpath)
         shutil.rmtree(self.BASETESTDIR)
 
     @onlyif_unicode_paths
     def test_1(self):
         """Test safe_execfile with non-ascii path
         """
         ip.safe_execfile(self.fname, {}, raise_exceptions=True)
 
 class ExitCodeChecks(tt.TempFileMixin):
     def test_exit_code_ok(self):
         self.system('exit 0')
         self.assertEqual(ip.user_ns['_exit_code'], 0)
 
     def test_exit_code_error(self):
         self.system('exit 1')
         self.assertEqual(ip.user_ns['_exit_code'], 1)
     
     @skipif(not hasattr(signal, 'SIGALRM'))
     def test_exit_code_signal(self):
         self.mktmp("import signal, time\n"
                    "signal.setitimer(signal.ITIMER_REAL, 0.1)\n"
                    "time.sleep(1)\n")
         self.system("%s %s" % (sys.executable, self.fname))
         self.assertEqual(ip.user_ns['_exit_code'], -signal.SIGALRM)
     
     @onlyif_cmds_exist("csh")
     def test_exit_code_signal_csh(self):
         SHELL = os.environ.get('SHELL', None)
         os.environ['SHELL'] = find_cmd("csh")
         try:
             self.test_exit_code_signal()
         finally:
             if SHELL is not None:
                 os.environ['SHELL'] = SHELL
             else:
                 del os.environ['SHELL']
 
 class TestSystemRaw(unittest.TestCase, ExitCodeChecks):
     system = ip.system_raw
 
     @onlyif_unicode_paths
     def test_1(self):
         """Test system_raw with non-ascii cmd
         """
         cmd = u'''python -c "'åäö'"   '''
         ip.system_raw(cmd)
 
     @mock.patch('subprocess.call', side_effect=KeyboardInterrupt)
     @mock.patch('os.system', side_effect=KeyboardInterrupt)
     def test_control_c(self, *mocks):
         try:
             self.system("sleep 1 # wont happen")
         except KeyboardInterrupt:
             self.fail("system call should intercept "
                       "keyboard interrupt from subprocess.call")
         self.assertEqual(ip.user_ns['_exit_code'], -signal.SIGINT)
 
 # TODO: Exit codes are currently ignored on Windows.
 class TestSystemPipedExitCode(unittest.TestCase, ExitCodeChecks):
     system = ip.system_piped
 
     @skip_win32
     def test_exit_code_ok(self):
         ExitCodeChecks.test_exit_code_ok(self)
 
     @skip_win32
     def test_exit_code_error(self):
         ExitCodeChecks.test_exit_code_error(self)
 
     @skip_win32
     def test_exit_code_signal(self):
         ExitCodeChecks.test_exit_code_signal(self)
 
 class TestModules(unittest.TestCase, tt.TempFileMixin):
     def test_extraneous_loads(self):
         """Test we're not loading modules on startup that we shouldn't.
         """
         self.mktmp("import sys\n"
                    "print('numpy' in sys.modules)\n"
                    "print('ipyparallel' in sys.modules)\n"
                    "print('ipykernel' in sys.modules)\n"
                    )
         out = "False\nFalse\nFalse\n"
         tt.ipexec_validate(self.fname, out)
 
 class Negator(ast.NodeTransformer):
     """Negates all number literals in an AST."""
     def visit_Num(self, node):
         node.n = -node.n
         return node
 
 class TestAstTransform(unittest.TestCase):
     def setUp(self):
         self.negator = Negator()
         ip.ast_transformers.append(self.negator)
     
     def tearDown(self):
         ip.ast_transformers.remove(self.negator)
     
     def test_run_cell(self):
         with tt.AssertPrints('-34'):
             ip.run_cell('print (12 + 22)')
         
         # A named reference to a number shouldn't be transformed.
         ip.user_ns['n'] = 55
         with tt.AssertNotPrints('-55'):
             ip.run_cell('print (n)')
     
     def test_timeit(self):
         called = set()
         def f(x):
             called.add(x)
         ip.push({'f':f})
         
         with tt.AssertPrints("best of "):
             ip.run_line_magic("timeit", "-n1 f(1)")
         self.assertEqual(called, {-1})
         called.clear()
         
         with tt.AssertPrints("best of "):
             ip.run_cell_magic("timeit", "-n1 f(2)", "f(3)")
         self.assertEqual(called, {-2, -3})
     
     def test_time(self):
         called = []
         def f(x):
             called.append(x)
         ip.push({'f':f})
         
         # Test with an expression
         with tt.AssertPrints("Wall time: "):
             ip.run_line_magic("time", "f(5+9)")
         self.assertEqual(called, [-14])
         called[:] = []
         
         # Test with a statement (different code path)
         with tt.AssertPrints("Wall time: "):
             ip.run_line_magic("time", "a = f(-3 + -2)")
         self.assertEqual(called, [5])
     
     def test_macro(self):
         ip.push({'a':10})
         # The AST transformation makes this do a+=-1
         ip.define_macro("amacro", "a+=1\nprint(a)")
         
         with tt.AssertPrints("9"):
             ip.run_cell("amacro")
         with tt.AssertPrints("8"):
             ip.run_cell("amacro")
 
 class IntegerWrapper(ast.NodeTransformer):
     """Wraps all integers in a call to Integer()"""
     def visit_Num(self, node):
         if isinstance(node.n, int):
             return ast.Call(func=ast.Name(id='Integer', ctx=ast.Load()),
                             args=[node], keywords=[])
         return node
 
 class TestAstTransform2(unittest.TestCase):
     def setUp(self):
         self.intwrapper = IntegerWrapper()
         ip.ast_transformers.append(self.intwrapper)
         
         self.calls = []
         def Integer(*args):
             self.calls.append(args)
             return args
         ip.push({"Integer": Integer})
     
     def tearDown(self):
         ip.ast_transformers.remove(self.intwrapper)
         del ip.user_ns['Integer']
     
     def test_run_cell(self):
         ip.run_cell("n = 2")
         self.assertEqual(self.calls, [(2,)])
         
         # This shouldn't throw an error
         ip.run_cell("o = 2.0")
         self.assertEqual(ip.user_ns['o'], 2.0)
     
     def test_timeit(self):
         called = set()
         def f(x):
             called.add(x)
         ip.push({'f':f})
         
         with tt.AssertPrints("best of "):
             ip.run_line_magic("timeit", "-n1 f(1)")
         self.assertEqual(called, {(1,)})
         called.clear()
         
         with tt.AssertPrints("best of "):
             ip.run_cell_magic("timeit", "-n1 f(2)", "f(3)")
         self.assertEqual(called, {(2,), (3,)})
 
 class ErrorTransformer(ast.NodeTransformer):
     """Throws an error when it sees a number."""
     def visit_Num(self, node):
         raise ValueError("test")
 
 class TestAstTransformError(unittest.TestCase):
     def test_unregistering(self):
         err_transformer = ErrorTransformer()
         ip.ast_transformers.append(err_transformer)
         
         with tt.AssertPrints("unregister", channel='stderr'):
             ip.run_cell("1 + 2")
         
         # This should have been removed.
         nt.assert_not_in(err_transformer, ip.ast_transformers)
 
 
 class StringRejector(ast.NodeTransformer):
     """Throws an InputRejected when it sees a string literal.
 
     Used to verify that NodeTransformers can signal that a piece of code should
     not be executed by throwing an InputRejected.
     """
 
     def visit_Str(self, node):
         raise InputRejected("test")
 
 
 class TestAstTransformInputRejection(unittest.TestCase):
 
     def setUp(self):
         self.transformer = StringRejector()
         ip.ast_transformers.append(self.transformer)
 
     def tearDown(self):
         ip.ast_transformers.remove(self.transformer)
 
     def test_input_rejection(self):
         """Check that NodeTransformers can reject input."""
 
         expect_exception_tb = tt.AssertPrints("InputRejected: test")
         expect_no_cell_output = tt.AssertNotPrints("'unsafe'", suppress=False)
 
         # Run the same check twice to verify that the transformer is not
         # disabled after raising.
         with expect_exception_tb, expect_no_cell_output:
             ip.run_cell("'unsafe'")
 
         with expect_exception_tb, expect_no_cell_output:
             res = ip.run_cell("'unsafe'")
 
         self.assertIsInstance(res.error_before_exec, InputRejected)
 
 def test__IPYTHON__():
     # This shouldn't raise a NameError, that's all
     __IPYTHON__
 
 
 class DummyRepr(object):
     def __repr__(self):
         return "DummyRepr"
     
     def _repr_html_(self):
         return "<b>dummy</b>"
     
     def _repr_javascript_(self):
         return "console.log('hi');", {'key': 'value'}
     
 
 def test_user_variables():
     # enable all formatters
     ip.display_formatter.active_types = ip.display_formatter.format_types
     
     ip.user_ns['dummy'] = d = DummyRepr()
     keys = {'dummy', 'doesnotexist'}
     r = ip.user_expressions({ key:key for key in keys})
 
     nt.assert_equal(keys, set(r.keys()))
     dummy = r['dummy']
     nt.assert_equal({'status', 'data', 'metadata'}, set(dummy.keys()))
     nt.assert_equal(dummy['status'], 'ok')
     data = dummy['data']
     metadata = dummy['metadata']
     nt.assert_equal(data.get('text/html'), d._repr_html_())
     js, jsmd = d._repr_javascript_()
     nt.assert_equal(data.get('application/javascript'), js)
     nt.assert_equal(metadata.get('application/javascript'), jsmd)
     
     dne = r['doesnotexist']
     nt.assert_equal(dne['status'], 'error')
     nt.assert_equal(dne['ename'], 'NameError')
     
     # back to text only
     ip.display_formatter.active_types = ['text/plain']
     
 def test_user_expression():
     # enable all formatters
     ip.display_formatter.active_types = ip.display_formatter.format_types
     query = {
         'a' : '1 + 2',
         'b' : '1/0',
     }
     r = ip.user_expressions(query)
     import pprint
     pprint.pprint(r)
     nt.assert_equal(set(r.keys()), set(query.keys()))
     a = r['a']
     nt.assert_equal({'status', 'data', 'metadata'}, set(a.keys()))
     nt.assert_equal(a['status'], 'ok')
     data = a['data']
     metadata = a['metadata']
     nt.assert_equal(data.get('text/plain'), '3')
     
     b = r['b']
     nt.assert_equal(b['status'], 'error')
     nt.assert_equal(b['ename'], 'ZeroDivisionError')
     
     # back to text only
     ip.display_formatter.active_types = ['text/plain']
     
 
 
 
 
 class TestSyntaxErrorTransformer(unittest.TestCase):
     """Check that SyntaxError raised by an input transformer is handled by run_cell()"""
 
     class SyntaxErrorTransformer(InputTransformer):
 
         def push(self, line):
             pos = line.find('syntaxerror')
             if pos >= 0:
                 e = SyntaxError('input contains "syntaxerror"')
                 e.text = line
                 e.offset = pos + 1
                 raise e
             return line
 
         def reset(self):
             pass
 
     def setUp(self):
         self.transformer = TestSyntaxErrorTransformer.SyntaxErrorTransformer()
         ip.input_splitter.python_line_transforms.append(self.transformer)
         ip.input_transformer_manager.python_line_transforms.append(self.transformer)
 
     def tearDown(self):
         ip.input_splitter.python_line_transforms.remove(self.transformer)
         ip.input_transformer_manager.python_line_transforms.remove(self.transformer)
 
     def test_syntaxerror_input_transformer(self):
         with tt.AssertPrints('1234'):
             ip.run_cell('1234')
         with tt.AssertPrints('SyntaxError: invalid syntax'):
             ip.run_cell('1 2 3')   # plain python syntax error
         with tt.AssertPrints('SyntaxError: input contains "syntaxerror"'):
             ip.run_cell('2345  # syntaxerror')  # input transformer syntax error
         with tt.AssertPrints('3456'):
             ip.run_cell('3456')
 
 
 
 def test_warning_suppression():
     ip.run_cell("import warnings")
     try:
         with tt.AssertPrints("UserWarning: asdf", channel="stderr"):
             ip.run_cell("warnings.warn('asdf')")
         # Here's the real test -- if we run that again, we should get the
         # warning again. Traditionally, each warning was only issued once per
         # IPython session (approximately), even if the user typed in new and
         # different code that should have also triggered the warning, leading
         # to much confusion.
         with tt.AssertPrints("UserWarning: asdf", channel="stderr"):
             ip.run_cell("warnings.warn('asdf')")
     finally:
         ip.run_cell("del warnings")
 
 
 def test_deprecation_warning():
     ip.run_cell("""
 import warnings
 def wrn():
     warnings.warn(
         "I AM  A WARNING",
         DeprecationWarning
     )
         """)
     try:
         with tt.AssertPrints("I AM  A WARNING", channel="stderr"):
             ip.run_cell("wrn()")
     finally:
         ip.run_cell("del warnings")
         ip.run_cell("del wrn")
 
 
 class TestImportNoDeprecate(tt.TempFileMixin):
 
     def setup(self):
         """Make a valid python temp file."""
         self.mktmp("""
 import warnings
 def wrn():
     warnings.warn(
         "I AM  A WARNING",
         DeprecationWarning
     )
 """)
 
     def test_no_dep(self):
         """
         No deprecation warning should be raised from imported functions
         """
         ip.run_cell("from {} import wrn".format(self.fname))
 
         with tt.AssertNotPrints("I AM  A WARNING"):
             ip.run_cell("wrn()")
         ip.run_cell("del wrn")

IPython/core/ultratb.py

@@ -1,1485 +1,1484 b''
 # -*- coding: utf-8 -*-
 """
 Verbose and colourful traceback formatting.
 
 **ColorTB**
 
 I've always found it a bit hard to visually parse tracebacks in Python.  The
 ColorTB class is a solution to that problem.  It colors the different parts of a
 traceback in a manner similar to what you would expect from a syntax-highlighting
 text editor.
 
 Installation instructions for ColorTB::
 
     import sys,ultratb
     sys.excepthook = ultratb.ColorTB()
 
 **VerboseTB**
 
 I've also included a port of Ka-Ping Yee's "cgitb.py" that produces all kinds
 of useful info when a traceback occurs.  Ping originally had it spit out HTML
 and intended it for CGI programmers, but why should they have all the fun?  I
 altered it to spit out colored text to the terminal.  It's a bit overwhelming,
 but kind of neat, and maybe useful for long-running programs that you believe
 are bug-free.  If a crash *does* occur in that type of program you want details.
 Give it a shot--you'll love it or you'll hate it.
 
 .. note::
 
   The Verbose mode prints the variables currently visible where the exception
   happened (shortening their strings if too long). This can potentially be
   very slow, if you happen to have a huge data structure whose string
   representation is complex to compute. Your computer may appear to freeze for
   a while with cpu usage at 100%. If this occurs, you can cancel the traceback
   with Ctrl-C (maybe hitting it more than once).
 
   If you encounter this kind of situation often, you may want to use the
   Verbose_novars mode instead of the regular Verbose, which avoids formatting
   variables (but otherwise includes the information and context given by
   Verbose).
 
 .. note::
 
   The verbose mode print all variables in the stack, which means it can
   potentially leak sensitive information like access keys, or unencryted
   password.
 
 Installation instructions for VerboseTB::
 
     import sys,ultratb
     sys.excepthook = ultratb.VerboseTB()
 
 Note:  Much of the code in this module was lifted verbatim from the standard
 library module 'traceback.py' and Ka-Ping Yee's 'cgitb.py'.
 
 Color schemes
 -------------
 
 The colors are defined in the class TBTools through the use of the
 ColorSchemeTable class. Currently the following exist:
 
   - NoColor: allows all of this module to be used in any terminal (the color
     escapes are just dummy blank strings).
 
   - Linux: is meant to look good in a terminal like the Linux console (black
     or very dark background).
 
   - LightBG: similar to Linux but swaps dark/light colors to be more readable
     in light background terminals.
 
 You can implement other color schemes easily, the syntax is fairly
 self-explanatory. Please send back new schemes you develop to the author for
 possible inclusion in future releases.
 
 Inheritance diagram:
 
 .. inheritance-diagram:: IPython.core.ultratb
    :parts: 3
 """
 
 #*****************************************************************************
 # Copyright (C) 2001 Nathaniel Gray <[e-mail]>
 # Copyright (C) 2001-2004 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.
 #*****************************************************************************
 
 from __future__ import absolute_import
 from __future__ import unicode_literals
 from __future__ import print_function
 
 import dis
 import inspect
 import keyword
 import linecache
 import os
 import pydoc
 import re
 import sys
 import time
 import tokenize
 import traceback
 import types
 
 try:  # Python 2
     generate_tokens = tokenize.generate_tokens
 except AttributeError:  # Python 3
     generate_tokens = tokenize.tokenize
 
 # For purposes of monkeypatching inspect to fix a bug in it.
 from inspect import getsourcefile, getfile, getmodule, \
     ismodule, isclass, ismethod, isfunction, istraceback, isframe, iscode
 
 # IPython's own modules
 # Modified pdb which doesn't damage IPython's readline handling
 from IPython import get_ipython
 from IPython.core import debugger
 from IPython.core.display_trap import DisplayTrap
 from IPython.core.excolors import exception_colors
 from IPython.utils import PyColorize
-from IPython.utils import io
 from IPython.utils import openpy
 from IPython.utils import path as util_path
 from IPython.utils import py3compat
 from IPython.utils import ulinecache
 from IPython.utils.data import uniq_stable
 from IPython.utils.terminal import get_terminal_size
 from logging import info, error
 
 import IPython.utils.colorable as colorable
 
 # Globals
 # amount of space to put line numbers before verbose tracebacks
 INDENT_SIZE = 8
 
 # Default color scheme.  This is used, for example, by the traceback
 # formatter.  When running in an actual IPython instance, the user's rc.colors
 # value is used, but having a module global makes this functionality available
 # to users of ultratb who are NOT running inside ipython.
 DEFAULT_SCHEME = 'NoColor'
 
 # ---------------------------------------------------------------------------
 # Code begins
 
 # Utility functions
 def inspect_error():
     """Print a message about internal inspect errors.
 
     These are unfortunately quite common."""
 
     error('Internal Python error in the inspect module.\n'
           'Below is the traceback from this internal error.\n')
 
 
 # This function is a monkeypatch we apply to the Python inspect module. We have
 # now found when it's needed (see discussion on issue gh-1456), and we have a
 # test case (IPython.core.tests.test_ultratb.ChangedPyFileTest) that fails if
 # the monkeypatch is not applied. TK, Aug 2012.
 def findsource(object):
     """Return the entire source file and starting line number for an object.
 
     The argument may be a module, class, method, function, traceback, frame,
     or code object.  The source code is returned as a list of all the lines
     in the file and the line number indexes a line in that list.  An IOError
     is raised if the source code cannot be retrieved.
 
     FIXED version with which we monkeypatch the stdlib to work around a bug."""
 
     file = getsourcefile(object) or getfile(object)
     # If the object is a frame, then trying to get the globals dict from its
     # module won't work. Instead, the frame object itself has the globals
     # dictionary.
     globals_dict = None
     if inspect.isframe(object):
         # XXX: can this ever be false?
         globals_dict = object.f_globals
     else:
         module = getmodule(object, file)
         if module:
             globals_dict = module.__dict__
     lines = linecache.getlines(file, globals_dict)
     if not lines:
         raise IOError('could not get source code')
 
     if ismodule(object):
         return lines, 0
 
     if isclass(object):
         name = object.__name__
         pat = re.compile(r'^(\s*)class\s*' + name + r'\b')
         # make some effort to find the best matching class definition:
         # use the one with the least indentation, which is the one
         # that's most probably not inside a function definition.
         candidates = []
         for i in range(len(lines)):
             match = pat.match(lines[i])
             if match:
                 # if it's at toplevel, it's already the best one
                 if lines[i][0] == 'c':
                     return lines, i
                 # else add whitespace to candidate list
                 candidates.append((match.group(1), i))
         if candidates:
             # this will sort by whitespace, and by line number,
             # less whitespace first
             candidates.sort()
             return lines, candidates[0][1]
         else:
             raise IOError('could not find class definition')
 
     if ismethod(object):
         object = object.__func__
     if isfunction(object):
         object = object.__code__
     if istraceback(object):
         object = object.tb_frame
     if isframe(object):
         object = object.f_code
     if iscode(object):
         if not hasattr(object, 'co_firstlineno'):
             raise IOError('could not find function definition')
         pat = re.compile(r'^(\s*def\s)|(.*(?<!\w)lambda(:|\s))|^(\s*@)')
         pmatch = pat.match
         # fperez - fix: sometimes, co_firstlineno can give a number larger than
         # the length of lines, which causes an error.  Safeguard against that.
         lnum = min(object.co_firstlineno, len(lines)) - 1
         while lnum > 0:
             if pmatch(lines[lnum]):
                 break
             lnum -= 1
 
         return lines, lnum
     raise IOError('could not find code object')
 
 
 # This is a patched version of inspect.getargs that applies the (unmerged)
 # patch for http://bugs.python.org/issue14611 by Stefano Taschini.  This fixes
 # https://github.com/ipython/ipython/issues/8205 and
 # https://github.com/ipython/ipython/issues/8293
 def getargs(co):
     """Get information about the arguments accepted by a code object.
 
     Three things are returned: (args, varargs, varkw), where 'args' is
     a list of argument names (possibly containing nested lists), and
     'varargs' and 'varkw' are the names of the * and ** arguments or None."""
     if not iscode(co):
         raise TypeError('{!r} is not a code object'.format(co))
 
     nargs = co.co_argcount
     names = co.co_varnames
     args = list(names[:nargs])
     step = 0
 
     # The following acrobatics are for anonymous (tuple) arguments.
     for i in range(nargs):
         if args[i][:1] in ('', '.'):
             stack, remain, count = [], [], []
             while step < len(co.co_code):
                 op = ord(co.co_code[step])
                 step = step + 1
                 if op >= dis.HAVE_ARGUMENT:
                     opname = dis.opname[op]
                     value = ord(co.co_code[step]) + ord(co.co_code[step+1])*256
                     step = step + 2
                     if opname in ('UNPACK_TUPLE', 'UNPACK_SEQUENCE'):
                         remain.append(value)
                         count.append(value)
                     elif opname in ('STORE_FAST', 'STORE_DEREF'):
                         if op in dis.haslocal:
                             stack.append(co.co_varnames[value])
                         elif op in dis.hasfree:
                             stack.append((co.co_cellvars + co.co_freevars)[value])
                         # Special case for sublists of length 1: def foo((bar))
                         # doesn't generate the UNPACK_TUPLE bytecode, so if
                         # `remain` is empty here, we have such a sublist.
                         if not remain:
                             stack[0] = [stack[0]]
                             break
                         else:
                             remain[-1] = remain[-1] - 1
                             while remain[-1] == 0:
                                 remain.pop()
                                 size = count.pop()
                                 stack[-size:] = [stack[-size:]]
                                 if not remain:
                                     break
                                 remain[-1] = remain[-1] - 1
                             if not remain:
                                 break
             args[i] = stack[0]
 
     varargs = None
     if co.co_flags & inspect.CO_VARARGS:
         varargs = co.co_varnames[nargs]
         nargs = nargs + 1
     varkw = None
     if co.co_flags & inspect.CO_VARKEYWORDS:
         varkw = co.co_varnames[nargs]
     return inspect.Arguments(args, varargs, varkw)
 
 
 # Monkeypatch inspect to apply our bugfix.
 def with_patch_inspect(f):
     """decorator for monkeypatching inspect.findsource"""
 
     def wrapped(*args, **kwargs):
         save_findsource = inspect.findsource
         save_getargs = inspect.getargs
         inspect.findsource = findsource
         inspect.getargs = getargs
         try:
             return f(*args, **kwargs)
         finally:
             inspect.findsource = save_findsource
             inspect.getargs = save_getargs
 
     return wrapped
 
 
 if py3compat.PY3:
     fixed_getargvalues = inspect.getargvalues
 else:
     # Fixes for https://github.com/ipython/ipython/issues/8293
     #       and https://github.com/ipython/ipython/issues/8205.
     # The relevant bug is caused by failure to correctly handle anonymous tuple
     # unpacking, which only exists in Python 2.
     fixed_getargvalues = with_patch_inspect(inspect.getargvalues)
 
 
 def fix_frame_records_filenames(records):
     """Try to fix the filenames in each record from inspect.getinnerframes().
 
     Particularly, modules loaded from within zip files have useless filenames
     attached to their code object, and inspect.getinnerframes() just uses it.
     """
     fixed_records = []
     for frame, filename, line_no, func_name, lines, index in records:
         # Look inside the frame's globals dictionary for __file__,
         # which should be better. However, keep Cython filenames since
         # we prefer the source filenames over the compiled .so file.
         filename = py3compat.cast_unicode_py2(filename, "utf-8")
         if not filename.endswith(('.pyx', '.pxd', '.pxi')):
             better_fn = frame.f_globals.get('__file__', None)
             if isinstance(better_fn, str):
                 # Check the type just in case someone did something weird with
                 # __file__. It might also be None if the error occurred during
                 # import.
                 filename = better_fn
         fixed_records.append((frame, filename, line_no, func_name, lines, index))
     return fixed_records
 
 
 @with_patch_inspect
 def _fixed_getinnerframes(etb, context=1, tb_offset=0):
     LNUM_POS, LINES_POS, INDEX_POS = 2, 4, 5
 
     records = fix_frame_records_filenames(inspect.getinnerframes(etb, context))
     # If the error is at the console, don't build any context, since it would
     # otherwise produce 5 blank lines printed out (there is no file at the
     # console)
     rec_check = records[tb_offset:]
     try:
         rname = rec_check[0][1]
         if rname == '<ipython console>' or rname.endswith('<string>'):
             return rec_check
     except IndexError:
         pass
 
     aux = traceback.extract_tb(etb)
     assert len(records) == len(aux)
     for i, (file, lnum, _, _) in zip(range(len(records)), aux):
         maybeStart = lnum - 1 - context // 2
         start = max(maybeStart, 0)
         end = start + context
         lines = ulinecache.getlines(file)[start:end]
         buf = list(records[i])
         buf[LNUM_POS] = lnum
         buf[INDEX_POS] = lnum - 1 - start
         buf[LINES_POS] = lines
         records[i] = tuple(buf)
     return records[tb_offset:]
 
 # Helper function -- largely belongs to VerboseTB, but we need the same
 # functionality to produce a pseudo verbose TB for SyntaxErrors, so that they
 # can be recognized properly by ipython.el's py-traceback-line-re
 # (SyntaxErrors have to be treated specially because they have no traceback)
 
 _parser = PyColorize.Parser()
 
 
 def _format_traceback_lines(lnum, index, lines, Colors, lvals=None, scheme=None):
     numbers_width = INDENT_SIZE - 1
     res = []
     i = lnum - index
 
     # This lets us get fully syntax-highlighted tracebacks.
     if scheme is None:
         ipinst = get_ipython()
         if ipinst is not None:
             scheme = ipinst.colors
         else:
             scheme = DEFAULT_SCHEME
 
     _line_format = _parser.format2
 
     for line in lines:
         line = py3compat.cast_unicode(line)
 
         new_line, err = _line_format(line, 'str', scheme)
         if not err: line = new_line
 
         if i == lnum:
             # This is the line with the error
             pad = numbers_width - len(str(i))
             num = '%s%s' % (debugger.make_arrow(pad), str(lnum))
             line = '%s%s%s %s%s' % (Colors.linenoEm, num,
                                     Colors.line, line, Colors.Normal)
         else:
             num = '%*s' % (numbers_width, i)
             line = '%s%s%s %s' % (Colors.lineno, num,
                                   Colors.Normal, line)
 
         res.append(line)
         if lvals and i == lnum:
             res.append(lvals + '\n')
         i = i + 1
     return res
 
 def is_recursion_error(etype, value, records):
     try:
         # RecursionError is new in Python 3.5
         recursion_error_type = RecursionError
     except NameError:
         recursion_error_type = RuntimeError
 
     # The default recursion limit is 1000, but some of that will be taken up
     # by stack frames in IPython itself. >500 frames probably indicates
     # a recursion error.
     return (etype is recursion_error_type) \
            and "recursion" in str(value).lower() \
            and len(records) > 500
 
 def find_recursion(etype, value, records):
     """Identify the repeating stack frames from a RecursionError traceback
 
     'records' is a list as returned by VerboseTB.get_records()
 
     Returns (last_unique, repeat_length)
     """
     # This involves a bit of guesswork - we want to show enough of the traceback
     # to indicate where the recursion is occurring. We guess that the innermost
     # quarter of the traceback (250 frames by default) is repeats, and find the
     # first frame (from in to out) that looks different.
     if not is_recursion_error(etype, value, records):
         return len(records), 0
 
     # Select filename, lineno, func_name to track frames with
     records = [r[1:4] for r in records]
     inner_frames = records[-(len(records)//4):]
     frames_repeated = set(inner_frames)
 
     last_seen_at = {}
     longest_repeat = 0
     i = len(records)
     for frame in reversed(records):
         i -= 1
         if frame not in frames_repeated:
             last_unique = i
             break
 
         if frame in last_seen_at:
             distance = last_seen_at[frame] - i
             longest_repeat = max(longest_repeat, distance)
 
         last_seen_at[frame] = i
     else:
         last_unique = 0 # The whole traceback was recursion
 
     return last_unique, longest_repeat
 
 #---------------------------------------------------------------------------
 # Module classes
 class TBTools(colorable.Colorable):
     """Basic tools used by all traceback printer classes."""
 
     # Number of frames to skip when reporting tracebacks
     tb_offset = 0
 
     def __init__(self, color_scheme='NoColor', call_pdb=False, ostream=None, parent=None, config=None):
         # Whether to call the interactive pdb debugger after printing
         # tracebacks or not
         super(TBTools, self).__init__(parent=parent, config=config)
         self.call_pdb = call_pdb
 
         # Output stream to write to.  Note that we store the original value in
         # a private attribute and then make the public ostream a property, so
         # that we can delay accessing io.stdout until runtime.  The way
         # things are written now, the io.stdout object is dynamically managed
         # so a reference to it should NEVER be stored statically.  This
         # property approach confines this detail to a single location, and all
         # subclasses can simply access self.ostream for writing.
         self._ostream = ostream
 
         # Create color table
         self.color_scheme_table = exception_colors()
 
         self.set_colors(color_scheme)
         self.old_scheme = color_scheme  # save initial value for toggles
 
         if call_pdb:
             self.pdb = debugger.Pdb(self.color_scheme_table.active_scheme_name)
         else:
             self.pdb = None
 
     def _get_ostream(self):
         """Output stream that exceptions are written to.
 
         Valid values are:
 
         - None: the default, which means that IPython will dynamically resolve
           to io.stdout.  This ensures compatibility with most tools, including
           Windows (where plain stdout doesn't recognize ANSI escapes).
 
         - Any object with 'write' and 'flush' attributes.
         """
-        return io.stdout if self._ostream is None else self._ostream
+        return sys.stdout if self._ostream is None else self._ostream
 
     def _set_ostream(self, val):
         assert val is None or (hasattr(val, 'write') and hasattr(val, 'flush'))
         self._ostream = val
 
     ostream = property(_get_ostream, _set_ostream)
 
     def set_colors(self, *args, **kw):
         """Shorthand access to the color table scheme selector method."""
 
         # Set own color table
         self.color_scheme_table.set_active_scheme(*args, **kw)
         # for convenience, set Colors to the active scheme
         self.Colors = self.color_scheme_table.active_colors
         # Also set colors of debugger
         if hasattr(self, 'pdb') and self.pdb is not None:
             self.pdb.set_colors(*args, **kw)
 
     def color_toggle(self):
         """Toggle between the currently active color scheme and NoColor."""
 
         if self.color_scheme_table.active_scheme_name == 'NoColor':
             self.color_scheme_table.set_active_scheme(self.old_scheme)
             self.Colors = self.color_scheme_table.active_colors
         else:
             self.old_scheme = self.color_scheme_table.active_scheme_name
             self.color_scheme_table.set_active_scheme('NoColor')
             self.Colors = self.color_scheme_table.active_colors
 
     def stb2text(self, stb):
         """Convert a structured traceback (a list) to a string."""
         return '\n'.join(stb)
 
     def text(self, etype, value, tb, tb_offset=None, context=5):
         """Return formatted traceback.
 
         Subclasses may override this if they add extra arguments.
         """
         tb_list = self.structured_traceback(etype, value, tb,
                                             tb_offset, context)
         return self.stb2text(tb_list)
 
     def structured_traceback(self, etype, evalue, tb, tb_offset=None,
                              context=5, mode=None):
         """Return a list of traceback frames.
 
         Must be implemented by each class.
         """
         raise NotImplementedError()
 
 
 #---------------------------------------------------------------------------
 class ListTB(TBTools):
     """Print traceback information from a traceback list, with optional color.
 
     Calling requires 3 arguments: (etype, evalue, elist)
     as would be obtained by::
     
       etype, evalue, tb = sys.exc_info()
       if tb:
         elist = traceback.extract_tb(tb)
       else:
         elist = None
 
     It can thus be used by programs which need to process the traceback before
     printing (such as console replacements based on the code module from the
     standard library).
 
     Because they are meant to be called without a full traceback (only a
     list), instances of this class can't call the interactive pdb debugger."""
 
     def __init__(self, color_scheme='NoColor', call_pdb=False, ostream=None, parent=None):
         TBTools.__init__(self, color_scheme=color_scheme, call_pdb=call_pdb,
                          ostream=ostream, parent=parent)
 
     def __call__(self, etype, value, elist):
         self.ostream.flush()
         self.ostream.write(self.text(etype, value, elist))
         self.ostream.write('\n')
 
     def structured_traceback(self, etype, value, elist, tb_offset=None,
                              context=5):
         """Return a color formatted string with the traceback info.
 
         Parameters
         ----------
         etype : exception type
           Type of the exception raised.
 
         value : object
           Data stored in the exception
 
         elist : list
           List of frames, see class docstring for details.
 
         tb_offset : int, optional
           Number of frames in the traceback to skip.  If not given, the
           instance value is used (set in constructor).
 
         context : int, optional
           Number of lines of context information to print.
 
         Returns
         -------
         String with formatted exception.
         """
         tb_offset = self.tb_offset if tb_offset is None else tb_offset
         Colors = self.Colors
         out_list = []
         if elist:
 
             if tb_offset and len(elist) > tb_offset:
                 elist = elist[tb_offset:]
 
             out_list.append('Traceback %s(most recent call last)%s:' %
                             (Colors.normalEm, Colors.Normal) + '\n')
             out_list.extend(self._format_list(elist))
         # The exception info should be a single entry in the list.
         lines = ''.join(self._format_exception_only(etype, value))
         out_list.append(lines)
 
         # Note: this code originally read:
 
         ## for line in lines[:-1]:
         ##     out_list.append(" "+line)
         ## out_list.append(lines[-1])
 
         # This means it was indenting everything but the last line by a little
         # bit.  I've disabled this for now, but if we see ugliness somewhere we
         # can restore it.
 
         return out_list
 
     def _format_list(self, extracted_list):
         """Format a list of traceback entry tuples for printing.
 
         Given a list of tuples as returned by extract_tb() or
         extract_stack(), return a list of strings ready for printing.
         Each string in the resulting list corresponds to the item with the
         same index in the argument list.  Each string ends in a newline;
         the strings may contain internal newlines as well, for those items
         whose source text line is not None.
 
         Lifted almost verbatim from traceback.py
         """
 
         Colors = self.Colors
         list = []
         for filename, lineno, name, line in extracted_list[:-1]:
             item = '  File %s"%s"%s, line %s%d%s, in %s%s%s\n' % \
                    (Colors.filename, py3compat.cast_unicode_py2(filename, "utf-8"), Colors.Normal,
                     Colors.lineno, lineno, Colors.Normal,
                     Colors.name, py3compat.cast_unicode_py2(name, "utf-8"), Colors.Normal)
             if line:
                 item += '    %s\n' % line.strip()
             list.append(item)
         # Emphasize the last entry
         filename, lineno, name, line = extracted_list[-1]
         item = '%s  File %s"%s"%s, line %s%d%s, in %s%s%s%s\n' % \
                (Colors.normalEm,
                 Colors.filenameEm, py3compat.cast_unicode_py2(filename, "utf-8"), Colors.normalEm,
                 Colors.linenoEm, lineno, Colors.normalEm,
                 Colors.nameEm, py3compat.cast_unicode_py2(name, "utf-8"), Colors.normalEm,
                 Colors.Normal)
         if line:
             item += '%s    %s%s\n' % (Colors.line, line.strip(),
                                       Colors.Normal)
         list.append(item)
         return list
 
     def _format_exception_only(self, etype, value):
         """Format the exception part of a traceback.
 
         The arguments are the exception type and value such as given by
         sys.exc_info()[:2]. The return value is a list of strings, each ending
         in a newline.  Normally, the list contains a single string; however,
         for SyntaxError exceptions, it contains several lines that (when
         printed) display detailed information about where the syntax error
         occurred.  The message indicating which exception occurred is the
         always last string in the list.
 
         Also lifted nearly verbatim from traceback.py
         """
         have_filedata = False
         Colors = self.Colors
         list = []
         stype = Colors.excName + etype.__name__ + Colors.Normal
         if value is None:
             # Not sure if this can still happen in Python 2.6 and above
             list.append(py3compat.cast_unicode(stype) + '\n')
         else:
             if issubclass(etype, SyntaxError):
                 have_filedata = True
                 if not value.filename: value.filename = "<string>"
                 if value.lineno:
                     lineno = value.lineno
                     textline = ulinecache.getline(value.filename, value.lineno)
                 else:
                     lineno = 'unknown'
                     textline = ''
                 list.append('%s  File %s"%s"%s, line %s%s%s\n' % \
                             (Colors.normalEm,
                              Colors.filenameEm, py3compat.cast_unicode(value.filename), Colors.normalEm,
                              Colors.linenoEm, lineno, Colors.Normal  ))
                 if textline == '':
                     textline = py3compat.cast_unicode(value.text, "utf-8")
 
                 if textline is not None:
                     i = 0
                     while i < len(textline) and textline[i].isspace():
                         i += 1
                     list.append('%s    %s%s\n' % (Colors.line,
                                                   textline.strip(),
                                                   Colors.Normal))
                     if value.offset is not None:
                         s = '    '
                         for c in textline[i:value.offset - 1]:
                             if c.isspace():
                                 s += c
                             else:
                                 s += ' '
                         list.append('%s%s^%s\n' % (Colors.caret, s,
                                                    Colors.Normal))
 
             try:
                 s = value.msg
             except Exception:
                 s = self._some_str(value)
             if s:
                 list.append('%s%s:%s %s\n' % (str(stype), Colors.excName,
                                               Colors.Normal, s))
             else:
                 list.append('%s\n' % str(stype))
 
         # sync with user hooks
         if have_filedata:
             ipinst = get_ipython()
             if ipinst is not None:
                 ipinst.hooks.synchronize_with_editor(value.filename, value.lineno, 0)
 
         return list
 
     def get_exception_only(self, etype, value):
         """Only print the exception type and message, without a traceback.
 
         Parameters
         ----------
         etype : exception type
         value : exception value
         """
         return ListTB.structured_traceback(self, etype, value, [])
 
     def show_exception_only(self, etype, evalue):
         """Only print the exception type and message, without a traceback.
 
         Parameters
         ----------
         etype : exception type
         value : exception value
         """
         # This method needs to use __call__ from *this* class, not the one from
         # a subclass whose signature or behavior may be different
         ostream = self.ostream
         ostream.flush()
         ostream.write('\n'.join(self.get_exception_only(etype, evalue)))
         ostream.flush()
 
     def _some_str(self, value):
         # Lifted from traceback.py
         try:
             return str(value)
         except:
             return '<unprintable %s object>' % type(value).__name__
 
 
 #----------------------------------------------------------------------------
 class VerboseTB(TBTools):
     """A port of Ka-Ping Yee's cgitb.py module that outputs color text instead
     of HTML.  Requires inspect and pydoc.  Crazy, man.
 
     Modified version which optionally strips the topmost entries from the
     traceback, to be used with alternate interpreters (because their own code
     would appear in the traceback)."""
 
     def __init__(self, color_scheme='Linux', call_pdb=False, ostream=None,
                  tb_offset=0, long_header=False, include_vars=True,
                  check_cache=None):
         """Specify traceback offset, headers and color scheme.
 
         Define how many frames to drop from the tracebacks. Calling it with
         tb_offset=1 allows use of this handler in interpreters which will have
         their own code at the top of the traceback (VerboseTB will first
         remove that frame before printing the traceback info)."""
         TBTools.__init__(self, color_scheme=color_scheme, call_pdb=call_pdb,
                          ostream=ostream)
         self.tb_offset = tb_offset
         self.long_header = long_header
         self.include_vars = include_vars
         # By default we use linecache.checkcache, but the user can provide a
         # different check_cache implementation.  This is used by the IPython
         # kernel to provide tracebacks for interactive code that is cached,
         # by a compiler instance that flushes the linecache but preserves its
         # own code cache.
         if check_cache is None:
             check_cache = linecache.checkcache
         self.check_cache = check_cache
 
     def format_records(self, records, last_unique, recursion_repeat):
         """Format the stack frames of the traceback"""
         frames = []
         for r in records[:last_unique+recursion_repeat+1]:
             #print '*** record:',file,lnum,func,lines,index  # dbg
             frames.append(self.format_record(*r))
 
         if recursion_repeat:
             frames.append('... last %d frames repeated, from the frame below ...\n' % recursion_repeat)
             frames.append(self.format_record(*records[last_unique+recursion_repeat+1]))
 
         return frames
 
     def format_record(self, frame, file, lnum, func, lines, index):
         """Format a single stack frame"""
         Colors = self.Colors  # just a shorthand + quicker name lookup
         ColorsNormal = Colors.Normal  # used a lot
         col_scheme = self.color_scheme_table.active_scheme_name
         indent = ' ' * INDENT_SIZE
         em_normal = '%s\n%s%s' % (Colors.valEm, indent, ColorsNormal)
         undefined = '%sundefined%s' % (Colors.em, ColorsNormal)
         tpl_link = '%s%%s%s' % (Colors.filenameEm, ColorsNormal)
         tpl_call = 'in %s%%s%s%%s%s' % (Colors.vName, Colors.valEm,
                                         ColorsNormal)
         tpl_call_fail = 'in %s%%s%s(***failed resolving arguments***)%s' % \
                         (Colors.vName, Colors.valEm, ColorsNormal)
         tpl_local_var = '%s%%s%s' % (Colors.vName, ColorsNormal)
         tpl_global_var = '%sglobal%s %s%%s%s' % (Colors.em, ColorsNormal,
                                                  Colors.vName, ColorsNormal)
         tpl_name_val = '%%s %s= %%s%s' % (Colors.valEm, ColorsNormal)
 
         tpl_line = '%s%%s%s %%s' % (Colors.lineno, ColorsNormal)
         tpl_line_em = '%s%%s%s %%s%s' % (Colors.linenoEm, Colors.line,
                                          ColorsNormal)
 
         abspath = os.path.abspath
 
 
         if not file:
             file = '?'
         elif file.startswith(str("<")) and file.endswith(str(">")):
             # Not a real filename, no problem...
             pass
         elif not os.path.isabs(file):
             # Try to make the filename absolute by trying all
             # sys.path entries (which is also what linecache does)
             for dirname in sys.path:
                 try:
                     fullname = os.path.join(dirname, file)
                     if os.path.isfile(fullname):
                         file = os.path.abspath(fullname)
                         break
                 except Exception:
                     # Just in case that sys.path contains very
                     # strange entries...
                     pass
 
         file = py3compat.cast_unicode(file, util_path.fs_encoding)
         link = tpl_link % file
         args, varargs, varkw, locals = fixed_getargvalues(frame)
 
         if func == '?':
             call = ''
         else:
             # Decide whether to include variable details or not
             var_repr = self.include_vars and eqrepr or nullrepr
             try:
                 call = tpl_call % (func, inspect.formatargvalues(args,
                                                                  varargs, varkw,
                                                                  locals, formatvalue=var_repr))
             except KeyError:
                 # This happens in situations like errors inside generator
                 # expressions, where local variables are listed in the
                 # line, but can't be extracted from the frame.  I'm not
                 # 100% sure this isn't actually a bug in inspect itself,
                 # but since there's no info for us to compute with, the
                 # best we can do is report the failure and move on.  Here
                 # we must *not* call any traceback construction again,
                 # because that would mess up use of %debug later on.  So we
                 # simply report the failure and move on.  The only
                 # limitation will be that this frame won't have locals
                 # listed in the call signature.  Quite subtle problem...
                 # I can't think of a good way to validate this in a unit
                 # test, but running a script consisting of:
                 #  dict( (k,v.strip()) for (k,v) in range(10) )
                 # will illustrate the error, if this exception catch is
                 # disabled.
                 call = tpl_call_fail % func
 
         # Don't attempt to tokenize binary files.
         if file.endswith(('.so', '.pyd', '.dll')):
             return '%s %s\n' % (link, call)
 
         elif file.endswith(('.pyc', '.pyo')):
             # Look up the corresponding source file.
             file = openpy.source_from_cache(file)
 
         def linereader(file=file, lnum=[lnum], getline=ulinecache.getline):
             line = getline(file, lnum[0])
             lnum[0] += 1
             return line
 
         # Build the list of names on this line of code where the exception
         # occurred.
         try:
             names = []
             name_cont = False
 
             for token_type, token, start, end, line in generate_tokens(linereader):
                 # build composite names
                 if token_type == tokenize.NAME and token not in keyword.kwlist:
                     if name_cont:
                         # Continuation of a dotted name
                         try:
                             names[-1].append(token)
                         except IndexError:
                             names.append([token])
                         name_cont = False
                     else:
                         # Regular new names.  We append everything, the caller
                         # will be responsible for pruning the list later.  It's
                         # very tricky to try to prune as we go, b/c composite
                         # names can fool us.  The pruning at the end is easy
                         # to do (or the caller can print a list with repeated
                         # names if so desired.
                         names.append([token])
                 elif token == '.':
                     name_cont = True
                 elif token_type == tokenize.NEWLINE:
                     break
 
         except (IndexError, UnicodeDecodeError, SyntaxError):
             # signals exit of tokenizer
             # SyntaxError can occur if the file is not actually Python
             #  - see gh-6300
             pass
         except tokenize.TokenError as msg:
             _m = ("An unexpected error occurred while tokenizing input\n"
                   "The following traceback may be corrupted or invalid\n"
                   "The error message is: %s\n" % msg)
             error(_m)
 
         # Join composite names (e.g. "dict.fromkeys")
         names = ['.'.join(n) for n in names]
         # prune names list of duplicates, but keep the right order
         unique_names = uniq_stable(names)
 
         # Start loop over vars
         lvals = []
         if self.include_vars:
             for name_full in unique_names:
                 name_base = name_full.split('.', 1)[0]
                 if name_base in frame.f_code.co_varnames:
                     if name_base in locals:
                         try:
                             value = repr(eval(name_full, locals))
                         except:
                             value = undefined
                     else:
                         value = undefined
                     name = tpl_local_var % name_full
                 else:
                     if name_base in frame.f_globals:
                         try:
                             value = repr(eval(name_full, frame.f_globals))
                         except:
                             value = undefined
                     else:
                         value = undefined
                     name = tpl_global_var % name_full
                 lvals.append(tpl_name_val % (name, value))
         if lvals:
             lvals = '%s%s' % (indent, em_normal.join(lvals))
         else:
             lvals = ''
 
         level = '%s %s\n' % (link, call)
 
         if index is None:
             return level
         else:
             return '%s%s' % (level, ''.join(
                 _format_traceback_lines(lnum, index, lines, Colors, lvals,
                                         col_scheme)))
 
     def prepare_chained_exception_message(self, cause):
         direct_cause = "\nThe above exception was the direct cause of the following exception:\n"
         exception_during_handling = "\nDuring handling of the above exception, another exception occurred:\n"
 
         if cause:
             message = [[direct_cause]]
         else:
             message = [[exception_during_handling]]
         return message
 
     def prepare_header(self, etype, long_version=False):
         colors = self.Colors  # just a shorthand + quicker name lookup
         colorsnormal = colors.Normal  # used a lot
         exc = '%s%s%s' % (colors.excName, etype, colorsnormal)
         width = min(75, get_terminal_size()[0])
         if long_version:
             # Header with the exception type, python version, and date
             pyver = 'Python ' + sys.version.split()[0] + ': ' + sys.executable
             date = time.ctime(time.time())
 
             head = '%s%s%s\n%s%s%s\n%s' % (colors.topline, '-' * width, colorsnormal,
                                            exc, ' ' * (width - len(str(etype)) - len(pyver)),
                                            pyver, date.rjust(width) )
             head += "\nA problem occurred executing Python code.  Here is the sequence of function" \
                     "\ncalls leading up to the error, with the most recent (innermost) call last."
         else:
             # Simplified header
             head = '%s%s' % (exc, 'Traceback (most recent call last)'. \
                              rjust(width - len(str(etype))) )
 
         return head
 
     def format_exception(self, etype, evalue):
         colors = self.Colors  # just a shorthand + quicker name lookup
         colorsnormal = colors.Normal  # used a lot
         indent = ' ' * INDENT_SIZE
         # Get (safely) a string form of the exception info
         try:
             etype_str, evalue_str = map(str, (etype, evalue))
         except:
             # User exception is improperly defined.
             etype, evalue = str, sys.exc_info()[:2]
             etype_str, evalue_str = map(str, (etype, evalue))
         # ... and format it
         exception = ['%s%s%s: %s' % (colors.excName, etype_str,
                                      colorsnormal, py3compat.cast_unicode(evalue_str))]
 
         if (not py3compat.PY3) and type(evalue) is types.InstanceType:
             try:
                 names = [w for w in dir(evalue) if isinstance(w, py3compat.string_types)]
             except:
                 # Every now and then, an object with funny internals blows up
                 # when dir() is called on it.  We do the best we can to report
                 # the problem and continue
                 _m = '%sException reporting error (object with broken dir())%s:'
                 exception.append(_m % (colors.excName, colorsnormal))
                 etype_str, evalue_str = map(str, sys.exc_info()[:2])
                 exception.append('%s%s%s: %s' % (colors.excName, etype_str,
                                                  colorsnormal, py3compat.cast_unicode(evalue_str)))
                 names = []
             for name in names:
                 value = text_repr(getattr(evalue, name))
                 exception.append('\n%s%s = %s' % (indent, name, value))
 
         return exception
 
     def format_exception_as_a_whole(self, etype, evalue, etb, number_of_lines_of_context, tb_offset):
         """Formats the header, traceback and exception message for a single exception.
 
         This may be called multiple times by Python 3 exception chaining
         (PEP 3134).
         """
         # some locals
         orig_etype = etype
         try:
             etype = etype.__name__
         except AttributeError:
             pass
 
         tb_offset = self.tb_offset if tb_offset is None else tb_offset
         head = self.prepare_header(etype, self.long_header)
         records = self.get_records(etb, number_of_lines_of_context, tb_offset)
 
         if records is None:
             return ""
 
         last_unique, recursion_repeat = find_recursion(orig_etype, evalue, records)
 
         frames = self.format_records(records, last_unique, recursion_repeat)
 
         formatted_exception = self.format_exception(etype, evalue)
         if records:
             filepath, lnum = records[-1][1:3]
             filepath = os.path.abspath(filepath)
             ipinst = get_ipython()
             if ipinst is not None:
                 ipinst.hooks.synchronize_with_editor(filepath, lnum, 0)
 
         return [[head] + frames + [''.join(formatted_exception[0])]]
 
     def get_records(self, etb, number_of_lines_of_context, tb_offset):
         try:
             # Try the default getinnerframes and Alex's: Alex's fixes some
             # problems, but it generates empty tracebacks for console errors
             # (5 blanks lines) where none should be returned.
             return _fixed_getinnerframes(etb, number_of_lines_of_context, tb_offset)
         except:
             # FIXME: I've been getting many crash reports from python 2.3
             # users, traceable to inspect.py.  If I can find a small test-case
             # to reproduce this, I should either write a better workaround or
             # file a bug report against inspect (if that's the real problem).
             # So far, I haven't been able to find an isolated example to
             # reproduce the problem.
             inspect_error()
             traceback.print_exc(file=self.ostream)
             info('\nUnfortunately, your original traceback can not be constructed.\n')
             return None
 
     def get_parts_of_chained_exception(self, evalue):
         def get_chained_exception(exception_value):
             cause = getattr(exception_value, '__cause__', None)
             if cause:
                 return cause
             if getattr(exception_value, '__suppress_context__', False):
                 return None
             return getattr(exception_value, '__context__', None)
 
         chained_evalue = get_chained_exception(evalue)
 
         if chained_evalue:
             return chained_evalue.__class__, chained_evalue, chained_evalue.__traceback__
 
     def structured_traceback(self, etype, evalue, etb, tb_offset=None,
                              number_of_lines_of_context=5):
         """Return a nice text document describing the traceback."""
 
         formatted_exception = self.format_exception_as_a_whole(etype, evalue, etb, number_of_lines_of_context,
                                                                tb_offset)
 
         colors = self.Colors  # just a shorthand + quicker name lookup
         colorsnormal = colors.Normal  # used a lot
         head = '%s%s%s' % (colors.topline, '-' * min(75, get_terminal_size()[0]), colorsnormal)
         structured_traceback_parts = [head]
         if py3compat.PY3:
             chained_exceptions_tb_offset = 0
             lines_of_context = 3
             formatted_exceptions = formatted_exception
             exception = self.get_parts_of_chained_exception(evalue)
             if exception:
                 formatted_exceptions += self.prepare_chained_exception_message(evalue.__cause__)
                 etype, evalue, etb = exception
             else:
                 evalue = None
             chained_exc_ids = set()
             while evalue:
                 formatted_exceptions += self.format_exception_as_a_whole(etype, evalue, etb, lines_of_context,
                                                                          chained_exceptions_tb_offset)
                 exception = self.get_parts_of_chained_exception(evalue)
 
                 if exception and not id(exception[1]) in chained_exc_ids:
                     chained_exc_ids.add(id(exception[1])) # trace exception to avoid infinite 'cause' loop
                     formatted_exceptions += self.prepare_chained_exception_message(evalue.__cause__)
                     etype, evalue, etb = exception
                 else:
                     evalue = None
 
             # we want to see exceptions in a reversed order:
             # the first exception should be on top
             for formatted_exception in reversed(formatted_exceptions):
                 structured_traceback_parts += formatted_exception
         else:
             structured_traceback_parts += formatted_exception[0]
 
         return structured_traceback_parts
 
     def debugger(self, force=False):
         """Call up the pdb debugger if desired, always clean up the tb
         reference.
 
         Keywords:
 
           - force(False): by default, this routine checks the instance call_pdb
             flag and does not actually invoke the debugger if the flag is false.
             The 'force' option forces the debugger to activate even if the flag
             is false.
 
         If the call_pdb flag is set, the pdb interactive debugger is
         invoked. In all cases, the self.tb reference to the current traceback
         is deleted to prevent lingering references which hamper memory
         management.
 
         Note that each call to pdb() does an 'import readline', so if your app
         requires a special setup for the readline completers, you'll have to
         fix that by hand after invoking the exception handler."""
 
         if force or self.call_pdb:
             if self.pdb is None:
                 self.pdb = debugger.Pdb(
                     self.color_scheme_table.active_scheme_name)
             # the system displayhook may have changed, restore the original
             # for pdb
             display_trap = DisplayTrap(hook=sys.__displayhook__)
             with display_trap:
                 self.pdb.reset()
                 # Find the right frame so we don't pop up inside ipython itself
                 if hasattr(self, 'tb') and self.tb is not None:
                     etb = self.tb
                 else:
                     etb = self.tb = sys.last_traceback
                 while self.tb is not None and self.tb.tb_next is not None:
                     self.tb = self.tb.tb_next
                 if etb and etb.tb_next:
                     etb = etb.tb_next
                 self.pdb.botframe = etb.tb_frame
                 self.pdb.interaction(self.tb.tb_frame, self.tb)
 
         if hasattr(self, 'tb'):
             del self.tb
 
     def handler(self, info=None):
         (etype, evalue, etb) = info or sys.exc_info()
         self.tb = etb
         ostream = self.ostream
         ostream.flush()
         ostream.write(self.text(etype, evalue, etb))
         ostream.write('\n')
         ostream.flush()
 
     # Changed so an instance can just be called as VerboseTB_inst() and print
     # out the right info on its own.
     def __call__(self, etype=None, evalue=None, etb=None):
         """This hook can replace sys.excepthook (for Python 2.1 or higher)."""
         if etb is None:
             self.handler()
         else:
             self.handler((etype, evalue, etb))
         try:
             self.debugger()
         except KeyboardInterrupt:
             print("\nKeyboardInterrupt")
 
 
 #----------------------------------------------------------------------------
 class FormattedTB(VerboseTB, ListTB):
     """Subclass ListTB but allow calling with a traceback.
 
     It can thus be used as a sys.excepthook for Python > 2.1.
 
     Also adds 'Context' and 'Verbose' modes, not available in ListTB.
 
     Allows a tb_offset to be specified. This is useful for situations where
     one needs to remove a number of topmost frames from the traceback (such as
     occurs with python programs that themselves execute other python code,
     like Python shells).  """
 
     def __init__(self, mode='Plain', color_scheme='Linux', call_pdb=False,
                  ostream=None,
                  tb_offset=0, long_header=False, include_vars=False,
                  check_cache=None):
 
         # NEVER change the order of this list. Put new modes at the end:
         self.valid_modes = ['Plain', 'Context', 'Verbose']
         self.verbose_modes = self.valid_modes[1:3]
 
         VerboseTB.__init__(self, color_scheme=color_scheme, call_pdb=call_pdb,
                            ostream=ostream, tb_offset=tb_offset,
                            long_header=long_header, include_vars=include_vars,
                            check_cache=check_cache)
 
         # Different types of tracebacks are joined with different separators to
         # form a single string.  They are taken from this dict
         self._join_chars = dict(Plain='', Context='\n', Verbose='\n')
         # set_mode also sets the tb_join_char attribute
         self.set_mode(mode)
 
     def _extract_tb(self, tb):
         if tb:
             return traceback.extract_tb(tb)
         else:
             return None
 
     def structured_traceback(self, etype, value, tb, tb_offset=None, number_of_lines_of_context=5):
         tb_offset = self.tb_offset if tb_offset is None else tb_offset
         mode = self.mode
         if mode in self.verbose_modes:
             # Verbose modes need a full traceback
             return VerboseTB.structured_traceback(
                 self, etype, value, tb, tb_offset, number_of_lines_of_context
             )
         else:
             # We must check the source cache because otherwise we can print
             # out-of-date source code.
             self.check_cache()
             # Now we can extract and format the exception
             elist = self._extract_tb(tb)
             return ListTB.structured_traceback(
                 self, etype, value, elist, tb_offset, number_of_lines_of_context
             )
 
     def stb2text(self, stb):
         """Convert a structured traceback (a list) to a string."""
         return self.tb_join_char.join(stb)
 
 
     def set_mode(self, mode=None):
         """Switch to the desired mode.
 
         If mode is not specified, cycles through the available modes."""
 
         if not mode:
             new_idx = (self.valid_modes.index(self.mode) + 1 ) % \
                       len(self.valid_modes)
             self.mode = self.valid_modes[new_idx]
         elif mode not in self.valid_modes:
             raise ValueError('Unrecognized mode in FormattedTB: <' + mode + '>\n'
                                                                             'Valid modes: ' + str(self.valid_modes))
         else:
             self.mode = mode
         # include variable details only in 'Verbose' mode
         self.include_vars = (self.mode == self.valid_modes[2])
         # Set the join character for generating text tracebacks
         self.tb_join_char = self._join_chars[self.mode]
 
     # some convenient shortcuts
     def plain(self):
         self.set_mode(self.valid_modes[0])
 
     def context(self):
         self.set_mode(self.valid_modes[1])
 
     def verbose(self):
         self.set_mode(self.valid_modes[2])
 
 
 #----------------------------------------------------------------------------
 class AutoFormattedTB(FormattedTB):
     """A traceback printer which can be called on the fly.
 
     It will find out about exceptions by itself.
 
     A brief example::
 
         AutoTB = AutoFormattedTB(mode = 'Verbose',color_scheme='Linux')
         try:
           ...
         except:
           AutoTB()  # or AutoTB(out=logfile) where logfile is an open file object
     """
 
     def __call__(self, etype=None, evalue=None, etb=None,
                  out=None, tb_offset=None):
         """Print out a formatted exception traceback.
 
         Optional arguments:
           - out: an open file-like object to direct output to.
 
           - tb_offset: the number of frames to skip over in the stack, on a
           per-call basis (this overrides temporarily the instance's tb_offset
           given at initialization time.  """
 
         if out is None:
             out = self.ostream
         out.flush()
         out.write(self.text(etype, evalue, etb, tb_offset))
         out.write('\n')
         out.flush()
         # FIXME: we should remove the auto pdb behavior from here and leave
         # that to the clients.
         try:
             self.debugger()
         except KeyboardInterrupt:
             print("\nKeyboardInterrupt")
 
     def structured_traceback(self, etype=None, value=None, tb=None,
                              tb_offset=None, number_of_lines_of_context=5):
         if etype is None:
             etype, value, tb = sys.exc_info()
         self.tb = tb
         return FormattedTB.structured_traceback(
             self, etype, value, tb, tb_offset, number_of_lines_of_context)
 
 
 #---------------------------------------------------------------------------
 
 # A simple class to preserve Nathan's original functionality.
 class ColorTB(FormattedTB):
     """Shorthand to initialize a FormattedTB in Linux colors mode."""
 
     def __init__(self, color_scheme='Linux', call_pdb=0, **kwargs):
         FormattedTB.__init__(self, color_scheme=color_scheme,
                              call_pdb=call_pdb, **kwargs)
 
 
 class SyntaxTB(ListTB):
     """Extension which holds some state: the last exception value"""
 
     def __init__(self, color_scheme='NoColor'):
         ListTB.__init__(self, color_scheme)
         self.last_syntax_error = None
 
     def __call__(self, etype, value, elist):
         self.last_syntax_error = value
 
         ListTB.__call__(self, etype, value, elist)
 
     def structured_traceback(self, etype, value, elist, tb_offset=None,
                              context=5):
         # If the source file has been edited, the line in the syntax error can
         # be wrong (retrieved from an outdated cache). This replaces it with
         # the current value.
         if isinstance(value, SyntaxError) \
                 and isinstance(value.filename, py3compat.string_types) \
                 and isinstance(value.lineno, int):
             linecache.checkcache(value.filename)
             newtext = ulinecache.getline(value.filename, value.lineno)
             if newtext:
                 value.text = newtext
         return super(SyntaxTB, self).structured_traceback(etype, value, elist,
                                                           tb_offset=tb_offset, context=context)
 
     def clear_err_state(self):
         """Return the current error state and clear it"""
         e = self.last_syntax_error
         self.last_syntax_error = None
         return e
 
     def stb2text(self, stb):
         """Convert a structured traceback (a list) to a string."""
         return ''.join(stb)
 
 
 # some internal-use functions
 def text_repr(value):
     """Hopefully pretty robust repr equivalent."""
     # this is pretty horrible but should always return *something*
     try:
         return pydoc.text.repr(value)
     except KeyboardInterrupt:
         raise
     except:
         try:
             return repr(value)
         except KeyboardInterrupt:
             raise
         except:
             try:
                 # all still in an except block so we catch
                 # getattr raising
                 name = getattr(value, '__name__', None)
                 if name:
                     # ick, recursion
                     return text_repr(name)
                 klass = getattr(value, '__class__', None)
                 if klass:
                     return '%s instance' % text_repr(klass)
             except KeyboardInterrupt:
                 raise
             except:
                 return 'UNRECOVERABLE REPR FAILURE'
 
 
 def eqrepr(value, repr=text_repr):
     return '=%s' % repr(value)
 
 
 def nullrepr(value, repr=text_repr):
     return ''

IPython/lib/demo.py

@@ -1,583 +1,583 b''
 """Module for interactive demos using IPython.
 
 This module implements a few classes for running Python scripts interactively
 in IPython for demonstrations.  With very simple markup (a few tags in
 comments), you can control points where the script stops executing and returns
 control to IPython.
 
 
 Provided classes
 ----------------
 
 The classes are (see their docstrings for further details):
 
  - Demo: pure python demos
 
  - IPythonDemo: demos with input to be processed by IPython as if it had been
    typed interactively (so magics work, as well as any other special syntax you
    may have added via input prefilters).
 
  - LineDemo: single-line version of the Demo class.  These demos are executed
    one line at a time, and require no markup.
 
  - IPythonLineDemo: IPython version of the LineDemo class (the demo is
    executed a line at a time, but processed via IPython).
 
  - ClearMixin: mixin to make Demo classes with less visual clutter.  It
    declares an empty marquee and a pre_cmd that clears the screen before each
    block (see Subclassing below).
 
  - ClearDemo, ClearIPDemo: mixin-enabled versions of the Demo and IPythonDemo
    classes.
 
 Inheritance diagram:
 
 .. inheritance-diagram:: IPython.lib.demo
    :parts: 3
 
 Subclassing
 -----------
 
 The classes here all include a few methods meant to make customization by
 subclassing more convenient.  Their docstrings below have some more details:
 
   - marquee(): generates a marquee to provide visible on-screen markers at each
     block start and end.
 
   - pre_cmd(): run right before the execution of each block.
 
   - post_cmd(): run right after the execution of each block.  If the block
     raises an exception, this is NOT called.
 
 
 Operation
 ---------
 
 The file is run in its own empty namespace (though you can pass it a string of
 arguments as if in a command line environment, and it will see those as
 sys.argv).  But at each stop, the global IPython namespace is updated with the
 current internal demo namespace, so you can work interactively with the data
 accumulated so far.
 
 By default, each block of code is printed (with syntax highlighting) before
 executing it and you have to confirm execution.  This is intended to show the
 code to an audience first so you can discuss it, and only proceed with
 execution once you agree.  There are a few tags which allow you to modify this
 behavior.
 
 The supported tags are:
 
 # <demo> stop
 
   Defines block boundaries, the points where IPython stops execution of the
   file and returns to the interactive prompt.
 
   You can optionally mark the stop tag with extra dashes before and after the
   word 'stop', to help visually distinguish the blocks in a text editor:
 
   # <demo> --- stop ---
 
 
 # <demo> silent
 
   Make a block execute silently (and hence automatically).  Typically used in
   cases where you have some boilerplate or initialization code which you need
   executed but do not want to be seen in the demo.
 
 # <demo> auto
 
   Make a block execute automatically, but still being printed.  Useful for
   simple code which does not warrant discussion, since it avoids the extra
   manual confirmation.
 
 # <demo> auto_all
 
   This tag can _only_ be in the first block, and if given it overrides the
   individual auto tags to make the whole demo fully automatic (no block asks
   for confirmation).  It can also be given at creation time (or the attribute
   set later) to override what's in the file.
 
 While _any_ python file can be run as a Demo instance, if there are no stop
 tags the whole file will run in a single block (no different that calling
 first %pycat and then %run).  The minimal markup to make this useful is to
 place a set of stop tags; the other tags are only there to let you fine-tune
 the execution.
 
 This is probably best explained with the simple example file below.  You can
 copy this into a file named ex_demo.py, and try running it via::
 
     from IPython.demo import Demo
     d = Demo('ex_demo.py')
     d()
 
 Each time you call the demo object, it runs the next block.  The demo object
 has a few useful methods for navigation, like again(), edit(), jump(), seek()
 and back().  It can be reset for a new run via reset() or reloaded from disk
 (in case you've edited the source) via reload().  See their docstrings below.
 
 Note: To make this simpler to explore, a file called "demo-exercizer.py" has
 been added to the "docs/examples/core" directory.  Just cd to this directory in
 an IPython session, and type::
 
   %run demo-exercizer.py
 
 and then follow the directions.
 
 Example
 -------
 
 The following is a very simple example of a valid demo file.
 
 ::
 
     #################### EXAMPLE DEMO <ex_demo.py> ###############################
     '''A simple interactive demo to illustrate the use of IPython's Demo class.'''
 
     print 'Hello, welcome to an interactive IPython demo.'
 
     # The mark below defines a block boundary, which is a point where IPython will
     # stop execution and return to the interactive prompt. The dashes are actually
     # optional and used only as a visual aid to clearly separate blocks while
     # editing the demo code.
     # <demo> stop
 
     x = 1
     y = 2
 
     # <demo> stop
 
     # the mark below makes this block as silent
     # <demo> silent
 
     print 'This is a silent block, which gets executed but not printed.'
 
     # <demo> stop
     # <demo> auto
     print 'This is an automatic block.'
     print 'It is executed without asking for confirmation, but printed.'
     z = x+y
 
     print 'z=',x
 
     # <demo> stop
     # This is just another normal block.
     print 'z is now:', z
 
     print 'bye!'
     ################### END EXAMPLE DEMO <ex_demo.py> ############################
 """
 
 from __future__ import unicode_literals
 
 #*****************************************************************************
 #     Copyright (C) 2005-2006 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.
 #
 #*****************************************************************************
 from __future__ import print_function
 
 import os
 import re
 import shlex
 import sys
 
 from IPython.utils import io
 from IPython.utils.text import marquee
 from IPython.utils import openpy
 from IPython.utils import py3compat
 __all__ = ['Demo','IPythonDemo','LineDemo','IPythonLineDemo','DemoError']
 
 class DemoError(Exception): pass
 
 def re_mark(mark):
     return re.compile(r'^\s*#\s+<demo>\s+%s\s*$' % mark,re.MULTILINE)
 
 class Demo(object):
 
     re_stop     = re_mark('-*\s?stop\s?-*')
     re_silent   = re_mark('silent')
     re_auto     = re_mark('auto')
     re_auto_all = re_mark('auto_all')
 
     def __init__(self,src,title='',arg_str='',auto_all=None):
         """Make a new demo object.  To run the demo, simply call the object.
 
         See the module docstring for full details and an example (you can use
         IPython.Demo? in IPython to see it).
 
         Inputs:
 
           - src is either a file, or file-like object, or a
               string that can be resolved to a filename.
 
         Optional inputs:
 
           - title: a string to use as the demo name.  Of most use when the demo
             you are making comes from an object that has no filename, or if you
             want an alternate denotation distinct from the filename.
 
           - arg_str(''): a string of arguments, internally converted to a list
             just like sys.argv, so the demo script can see a similar
             environment.
 
           - auto_all(None): global flag to run all blocks automatically without
             confirmation.  This attribute overrides the block-level tags and
             applies to the whole demo.  It is an attribute of the object, and
             can be changed at runtime simply by reassigning it to a boolean
             value.
           """
         if hasattr(src, "read"):
              # It seems to be a file or a file-like object
             self.fname = "from a file-like object"
             if title == '':
                 self.title = "from a file-like object"
             else:
                 self.title = title
         else:
              # Assume it's a string or something that can be converted to one
             self.fname = src
             if title == '':
                 (filepath, filename) = os.path.split(src)
                 self.title = filename
             else:
                 self.title = title
         self.sys_argv = [src] + shlex.split(arg_str)
         self.auto_all = auto_all
         self.src = src
 
         # get a few things from ipython.  While it's a bit ugly design-wise,
         # it ensures that things like color scheme and the like are always in
         # sync with the ipython mode being used.  This class is only meant to
         # be used inside ipython anyways,  so it's OK.
         ip = get_ipython()  # this is in builtins whenever IPython is running
         self.ip_ns       = ip.user_ns
         self.ip_colorize = ip.pycolorize
         self.ip_showtb   = ip.showtraceback
         self.ip_run_cell = ip.run_cell
         self.shell       = ip
 
         # load user data and initialize data structures
         self.reload()
 
     def fload(self):
         """Load file object."""
         # read data and parse into blocks
         if hasattr(self, 'fobj') and self.fobj is not None:
            self.fobj.close()
         if hasattr(self.src, "read"):
              # It seems to be a file or a file-like object
             self.fobj = self.src
         else:
              # Assume it's a string or something that can be converted to one
             self.fobj = openpy.open(self.fname)
 
     def reload(self):
         """Reload source from disk and initialize state."""
         self.fload()
 
         self.src     = "".join(openpy.strip_encoding_cookie(self.fobj))
         src_b        = [b.strip() for b in self.re_stop.split(self.src) if b]
         self._silent = [bool(self.re_silent.findall(b)) for b in src_b]
         self._auto   = [bool(self.re_auto.findall(b)) for b in src_b]
 
         # if auto_all is not given (def. None), we read it from the file
         if self.auto_all is None:
             self.auto_all = bool(self.re_auto_all.findall(src_b[0]))
         else:
             self.auto_all = bool(self.auto_all)
 
         # Clean the sources from all markup so it doesn't get displayed when
         # running the demo
         src_blocks = []
         auto_strip = lambda s: self.re_auto.sub('',s)
         for i,b in enumerate(src_b):
             if self._auto[i]:
                 src_blocks.append(auto_strip(b))
             else:
                 src_blocks.append(b)
         # remove the auto_all marker
         src_blocks[0] = self.re_auto_all.sub('',src_blocks[0])
 
         self.nblocks = len(src_blocks)
         self.src_blocks = src_blocks
 
         # also build syntax-highlighted source
         self.src_blocks_colored = list(map(self.ip_colorize,self.src_blocks))
 
         # ensure clean namespace and seek offset
         self.reset()
 
     def reset(self):
         """Reset the namespace and seek pointer to restart the demo"""
         self.user_ns     = {}
         self.finished    = False
         self.block_index = 0
 
     def _validate_index(self,index):
         if index<0 or index>=self.nblocks:
             raise ValueError('invalid block index %s' % index)
 
     def _get_index(self,index):
         """Get the current block index, validating and checking status.
 
         Returns None if the demo is finished"""
 
         if index is None:
             if self.finished:
-                print('Demo finished.  Use <demo_name>.reset() if you want to rerun it.', file=io.stdout)
+                print('Demo finished.  Use <demo_name>.reset() if you want to rerun it.')
                 return None
             index = self.block_index
         else:
             self._validate_index(index)
         return index
 
     def seek(self,index):
         """Move the current seek pointer to the given block.
 
         You can use negative indices to seek from the end, with identical
         semantics to those of Python lists."""
         if index<0:
             index = self.nblocks + index
         self._validate_index(index)
         self.block_index = index
         self.finished = False
 
     def back(self,num=1):
         """Move the seek pointer back num blocks (default is 1)."""
         self.seek(self.block_index-num)
 
     def jump(self,num=1):
         """Jump a given number of blocks relative to the current one.
 
         The offset can be positive or negative, defaults to 1."""
         self.seek(self.block_index+num)
 
     def again(self):
         """Move the seek pointer back one block and re-execute."""
         self.back(1)
         self()
 
     def edit(self,index=None):
         """Edit a block.
 
         If no number is given, use the last block executed.
 
         This edits the in-memory copy of the demo, it does NOT modify the
         original source file.  If you want to do that, simply open the file in
         an editor and use reload() when you make changes to the file.  This
         method is meant to let you change a block during a demonstration for
         explanatory purposes, without damaging your original script."""
 
         index = self._get_index(index)
         if index is None:
             return
         # decrease the index by one (unless we're at the very beginning), so
         # that the default demo.edit() call opens up the sblock we've last run
         if index>0:
             index -= 1
 
         filename = self.shell.mktempfile(self.src_blocks[index])
         self.shell.hooks.editor(filename,1)
         with open(filename, 'r') as f:
             new_block = f.read()
         # update the source and colored block
         self.src_blocks[index] = new_block
         self.src_blocks_colored[index] = self.ip_colorize(new_block)
         self.block_index = index
         # call to run with the newly edited index
         self()
 
     def show(self,index=None):
         """Show a single block on screen"""
 
         index = self._get_index(index)
         if index is None:
             return
 
         print(self.marquee('<%s> block # %s (%s remaining)' %
-                           (self.title,index,self.nblocks-index-1)), file=io.stdout)
-        print(self.src_blocks_colored[index], file=io.stdout)
+                           (self.title,index,self.nblocks-index-1)))
+        print(self.src_blocks_colored[index])
         sys.stdout.flush()
 
     def show_all(self):
         """Show entire demo on screen, block by block"""
 
         fname = self.title
         title = self.title
         nblocks = self.nblocks
         silent = self._silent
         marquee = self.marquee
         for index,block in enumerate(self.src_blocks_colored):
             if silent[index]:
                 print(marquee('<%s> SILENT block # %s (%s remaining)' %
-                              (title,index,nblocks-index-1)), file=io.stdout)
+                              (title,index,nblocks-index-1)))
             else:
                 print(marquee('<%s> block # %s (%s remaining)' %
-                              (title,index,nblocks-index-1)), file=io.stdout)
-            print(block, end=' ', file=io.stdout)
+                              (title,index,nblocks-index-1)))
+            print(block, end=' ')
         sys.stdout.flush()
 
     def run_cell(self,source):
         """Execute a string with one or more lines of code"""
 
         exec(source, self.user_ns)
 
     def __call__(self,index=None):
         """run a block of the demo.
 
         If index is given, it should be an integer >=1 and <= nblocks.  This
         means that the calling convention is one off from typical Python
         lists.  The reason for the inconsistency is that the demo always
         prints 'Block n/N, and N is the total, so it would be very odd to use
         zero-indexing here."""
 
         index = self._get_index(index)
         if index is None:
             return
         try:
             marquee = self.marquee
             next_block = self.src_blocks[index]
             self.block_index += 1
             if self._silent[index]:
                 print(marquee('Executing silent block # %s (%s remaining)' %
-                              (index,self.nblocks-index-1)), file=io.stdout)
+                              (index,self.nblocks-index-1)))
             else:
                 self.pre_cmd()
                 self.show(index)
                 if self.auto_all or self._auto[index]:
-                    print(marquee('output:'), file=io.stdout)
+                    print(marquee('output:'))
                 else:
-                    print(marquee('Press <q> to quit, <Enter> to execute...'), end=' ', file=io.stdout)
+                    print(marquee('Press <q> to quit, <Enter> to execute...'), end=' ')
                     ans = py3compat.input().strip()
                     if ans:
-                        print(marquee('Block NOT executed'), file=io.stdout)
+                        print(marquee('Block NOT executed'))
                         return
             try:
                 save_argv = sys.argv
                 sys.argv = self.sys_argv
                 self.run_cell(next_block)
                 self.post_cmd()
             finally:
                 sys.argv = save_argv
 
         except:
             self.ip_showtb(filename=self.fname)
         else:
             self.ip_ns.update(self.user_ns)
 
         if self.block_index == self.nblocks:
             mq1 = self.marquee('END OF DEMO')
             if mq1:
                 # avoid spurious print >>io.stdout,s if empty marquees are used
-                print(file=io.stdout)
-                print(mq1, file=io.stdout)
-                print(self.marquee('Use <demo_name>.reset() if you want to rerun it.'), file=io.stdout)
+                print()
+                print(mq1)
+                print(self.marquee('Use <demo_name>.reset() if you want to rerun it.'))
             self.finished = True
 
     # These methods are meant to be overridden by subclasses who may wish to
     # customize the behavior of of their demos.
     def marquee(self,txt='',width=78,mark='*'):
         """Return the input string centered in a 'marquee'."""
         return marquee(txt,width,mark)
 
     def pre_cmd(self):
         """Method called before executing each block."""
         pass
 
     def post_cmd(self):
         """Method called after executing each block."""
         pass
 
 
 class IPythonDemo(Demo):
     """Class for interactive demos with IPython's input processing applied.
 
     This subclasses Demo, but instead of executing each block by the Python
     interpreter (via exec), it actually calls IPython on it, so that any input
     filters which may be in place are applied to the input block.
 
     If you have an interactive environment which exposes special input
     processing, you can use this class instead to write demo scripts which
     operate exactly as if you had typed them interactively.  The default Demo
     class requires the input to be valid, pure Python code.
     """
 
     def run_cell(self,source):
         """Execute a string with one or more lines of code"""
 
         self.shell.run_cell(source)
 
 class LineDemo(Demo):
     """Demo where each line is executed as a separate block.
 
     The input script should be valid Python code.
 
     This class doesn't require any markup at all, and it's meant for simple
     scripts (with no nesting or any kind of indentation) which consist of
     multiple lines of input to be executed, one at a time, as if they had been
     typed in the interactive prompt.
 
     Note: the input can not have *any* indentation, which means that only
     single-lines of input are accepted, not even function definitions are
     valid."""
 
     def reload(self):
         """Reload source from disk and initialize state."""
         # read data and parse into blocks
         self.fload()
         lines           = self.fobj.readlines()
         src_b           = [l for l in lines if l.strip()]
         nblocks         = len(src_b)
         self.src        = ''.join(lines)
         self._silent    = [False]*nblocks
         self._auto      = [True]*nblocks
         self.auto_all   = True
         self.nblocks    = nblocks
         self.src_blocks = src_b
 
         # also build syntax-highlighted source
         self.src_blocks_colored = map(self.ip_colorize,self.src_blocks)
 
         # ensure clean namespace and seek offset
         self.reset()
 
 
 class IPythonLineDemo(IPythonDemo,LineDemo):
     """Variant of the LineDemo class whose input is processed by IPython."""
     pass
 
 
 class ClearMixin(object):
     """Use this mixin to make Demo classes with less visual clutter.
 
     Demos using this mixin will clear the screen before every block and use
     blank marquees.
 
     Note that in order for the methods defined here to actually override those
     of the classes it's mixed with, it must go /first/ in the inheritance
     tree.  For example:
 
         class ClearIPDemo(ClearMixin,IPythonDemo): pass
 
     will provide an IPythonDemo class with the mixin's features.
     """
 
     def marquee(self,txt='',width=78,mark='*'):
         """Blank marquee that returns '' no matter what the input."""
         return ''
 
     def pre_cmd(self):
         """Method called before executing each block.
 
         This one simply clears the screen."""
         from IPython.utils.terminal import term_clear
         term_clear()
 
 class ClearDemo(ClearMixin,Demo):
     pass
 
 
 class ClearIPDemo(ClearMixin,IPythonDemo):
     pass

IPython/utils/io.py

@@ -1,227 +1,233 b''
 # encoding: utf-8
 """
 IO related utilities.
 """
 
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
 from __future__ import print_function
 from __future__ import absolute_import
 
 
 import atexit
 import os
 import sys
 import tempfile
 from warnings import warn
+
+from IPython.utils.decorators import undoc
 from .capture import CapturedIO, capture_output
 from .py3compat import string_types, input, PY3
 
-
+@undoc
 class IOStream:
 
     def __init__(self,stream, fallback=None):
         if not hasattr(stream,'write') or not hasattr(stream,'flush'):
             if fallback is not None:
                 stream = fallback
             else:
                 raise ValueError("fallback required, but not specified")
         self.stream = stream
         self._swrite = stream.write
 
         # clone all methods not overridden:
         def clone(meth):
             return not hasattr(self, meth) and not meth.startswith('_')
         for meth in filter(clone, dir(stream)):
             setattr(self, meth, getattr(stream, meth))
 
     def __repr__(self):
         cls = self.__class__
         tpl = '{mod}.{cls}({args})'
         return tpl.format(mod=cls.__module__, cls=cls.__name__, args=self.stream)
 
     def write(self,data):
+        warn('IOStream is deprecated, use sys.{stdin,stdout,stderr} instead',
+             DeprecationWarning, stacklevel=2)
         try:
             self._swrite(data)
         except:
             try:
                 # print handles some unicode issues which may trip a plain
                 # write() call.  Emulate write() by using an empty end
                 # argument.
                 print(data, end='', file=self.stream)
             except:
                 # if we get here, something is seriously broken.
                 print('ERROR - failed to write data to stream:', self.stream,
                       file=sys.stderr)
 
     def writelines(self, lines):
+        warn('IOStream is deprecated, use sys.{stdin,stdout,stderr} instead',
+             DeprecationWarning, stacklevel=2)
         if isinstance(lines, string_types):
             lines = [lines]
         for line in lines:
             self.write(line)
 
     # This class used to have a writeln method, but regular files and streams
     # in Python don't have this method. We need to keep this completely
     # compatible so we removed it.
 
     @property
     def closed(self):
         return self.stream.closed
 
     def close(self):
         pass
 
 # setup stdin/stdout/stderr to sys.stdin/sys.stdout/sys.stderr
 devnull = open(os.devnull, 'w') 
 atexit.register(devnull.close)
 stdin = IOStream(sys.stdin, fallback=devnull)
 stdout = IOStream(sys.stdout, fallback=devnull)
 stderr = IOStream(sys.stderr, fallback=devnull)
 
 class Tee(object):
     """A class to duplicate an output stream to stdout/err.
 
     This works in a manner very similar to the Unix 'tee' command.
 
     When the object is closed or deleted, it closes the original file given to
     it for duplication.
     """
     # Inspired by:
     # http://mail.python.org/pipermail/python-list/2007-May/442737.html
 
     def __init__(self, file_or_name, mode="w", channel='stdout'):
         """Construct a new Tee object.
 
         Parameters
         ----------
         file_or_name : filename or open filehandle (writable)
           File that will be duplicated
 
         mode : optional, valid mode for open().
           If a filename was give, open with this mode.
 
         channel : str, one of ['stdout', 'stderr']
         """
         if channel not in ['stdout', 'stderr']:
             raise ValueError('Invalid channel spec %s' % channel)
 
         if hasattr(file_or_name, 'write') and hasattr(file_or_name, 'seek'):
             self.file = file_or_name
         else:
             self.file = open(file_or_name, mode)
         self.channel = channel
         self.ostream = getattr(sys, channel)
         setattr(sys, channel, self)
         self._closed = False
 
     def close(self):
         """Close the file and restore the channel."""
         self.flush()
         setattr(sys, self.channel, self.ostream)
         self.file.close()
         self._closed = True
 
     def write(self, data):
         """Write data to both channels."""
         self.file.write(data)
         self.ostream.write(data)
         self.ostream.flush()
 
     def flush(self):
         """Flush both channels."""
         self.file.flush()
         self.ostream.flush()
 
     def __del__(self):
         if not self._closed:
             self.close()
 
 
 def ask_yes_no(prompt, default=None, interrupt=None):
     """Asks a question and returns a boolean (y/n) answer.
 
     If default is given (one of 'y','n'), it is used if the user input is
     empty. If interrupt is given (one of 'y','n'), it is used if the user
     presses Ctrl-C. Otherwise the question is repeated until an answer is
     given.
 
     An EOF is treated as the default answer.  If there is no default, an
     exception is raised to prevent infinite loops.
 
     Valid answers are: y/yes/n/no (match is not case sensitive)."""
 
     answers = {'y':True,'n':False,'yes':True,'no':False}
     ans = None
     while ans not in answers.keys():
         try:
             ans = input(prompt+' ').lower()
             if not ans:  # response was an empty string
                 ans = default
         except KeyboardInterrupt:
             if interrupt:
                 ans = interrupt
         except EOFError:
             if default in answers.keys():
                 ans = default
                 print()
             else:
                 raise
 
     return answers[ans]
 
 
 def temp_pyfile(src, ext='.py'):
     """Make a temporary python file, return filename and filehandle.
 
     Parameters
     ----------
     src : string or list of strings (no need for ending newlines if list)
       Source code to be written to the file.
 
     ext : optional, string
       Extension for the generated file.
 
     Returns
     -------
     (filename, open filehandle)
       It is the caller's responsibility to close the open file and unlink it.
     """
     fname = tempfile.mkstemp(ext)[1]
     f = open(fname,'w')
     f.write(src)
     f.flush()
     return fname, f
 
 def atomic_writing(*args, **kwargs):
     """DEPRECATED: moved to notebook.services.contents.fileio"""
     warn("IPython.utils.io.atomic_writing has moved to notebook.services.contents.fileio")
     from notebook.services.contents.fileio import atomic_writing
     return atomic_writing(*args, **kwargs)
 
 def raw_print(*args, **kw):
     """Raw print to sys.__stdout__, otherwise identical interface to print()."""
 
     print(*args, sep=kw.get('sep', ' '), end=kw.get('end', '\n'),
           file=sys.__stdout__)
     sys.__stdout__.flush()
 
 
 def raw_print_err(*args, **kw):
     """Raw print to sys.__stderr__, otherwise identical interface to print()."""
 
     print(*args, sep=kw.get('sep', ' '), end=kw.get('end', '\n'),
           file=sys.__stderr__)
     sys.__stderr__.flush()
 
 
 # Short aliases for quick debugging, do NOT use these in production code.
 rprint = raw_print
 rprinte = raw_print_err
 
 
 def unicode_std_stream(stream='stdout'):
     """DEPRECATED, moved to nbconvert.utils.io"""
     warn("IPython.utils.io.unicode_std_stream has moved to nbconvert.utils.io")
     from nbconvert.utils.io import unicode_std_stream
     return unicode_std_stream(stream)

IPython/utils/warn.py

@@ -1,60 +1,57 b''
 # encoding: utf-8
 """
 Utilities for warnings.  Shoudn't we just use the built in warnings module.
 """
 
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
 from __future__ import print_function
 
 import sys
-
-from IPython.utils import io
-
 import warnings
 
 warnings.warn("The module IPython.utils.warn is deprecated, use the standard warnings module instead", DeprecationWarning)
 
 def warn(msg,level=2,exit_val=1):
     """Standard warning printer. Gives formatting consistency.
 
     Output is sent to io.stderr (sys.stderr by default).
 
     Options:
 
     -level(2): allows finer control:
       0 -> Do nothing, dummy function.
       1 -> Print message.
       2 -> Print 'WARNING:' + message. (Default level).
       3 -> Print 'ERROR:' + message.
       4 -> Print 'FATAL ERROR:' + message and trigger a sys.exit(exit_val).
 
     -exit_val (1): exit value returned by sys.exit() for a level 4
     warning. Ignored for all other levels."""
     
     warnings.warn("The module IPython.utils.warn is deprecated, use the standard warnings module instead", DeprecationWarning)
     if level>0:
         header = ['','','WARNING: ','ERROR: ','FATAL ERROR: ']
-        print(header[level], msg, sep='', file=io.stderr)
+        print(header[level], msg, sep='', file=sys.stderr)
         if level == 4:
-            print('Exiting.\n', file=io.stderr)
+            print('Exiting.\n', file=sys.stderr)
             sys.exit(exit_val)
 
             
 def info(msg):
     """Equivalent to warn(msg,level=1)."""
 
     warn(msg,level=1)
 
     
 def error(msg):
     """Equivalent to warn(msg,level=3)."""
 
     warn(msg,level=3)
 
     
 def fatal(msg,exit_val=1):
     """Equivalent to warn(msg,exit_val=exit_val,level=4)."""
 
     warn(msg,exit_val=exit_val,level=4)