Small fixes as per @certik's review.

IPython/core/magics/basic.py

@@ -1,513 +1,513 b''
 """Implementation of basic magic functions.
 """
 #-----------------------------------------------------------------------------
 #  Copyright (c) 2012 The 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 io
 import sys
 from pprint import pformat
 
 # Our own packages
 from IPython.core.error import UsageError
 from IPython.core.magic import Magics, magics_class, line_magic
 from IPython.core.prefilter import ESC_MAGIC
 from IPython.utils.text import format_screen
 from IPython.core import magic_arguments, page
 from IPython.testing.skipdoctest import skip_doctest
 from IPython.utils.ipstruct import Struct
 from IPython.utils.path import unquote_filename
 from IPython.utils.warn import warn, error
 
 #-----------------------------------------------------------------------------
 # Magics class implementation
 #-----------------------------------------------------------------------------
 
 @magics_class
 class BasicMagics(Magics):
     """Magics that provide central IPython functionality.
 
     These are various magics that don't fit into specific categories but that
     are all part of the base 'IPython experience'."""
 
     def _lsmagic(self):
         mesc = ESC_MAGIC
         cesc = mesc*2
         mman = self.shell.magics_manager
         magics = mman.lsmagic()
         out = ['Available line magics:',
                mesc + ('  '+mesc).join(magics['line']),
                '',
                'Available cell magics:',
                cesc + ('  '+cesc).join(magics['cell']),
                '',
                mman.auto_status()]
         return '\n'.join(out)
 
     @line_magic
     def lsmagic(self, parameter_s=''):
         """List currently available magic functions."""
         print(self._lsmagic())
 
     @line_magic
     def magic(self, parameter_s=''):
         """Print information about the magic function system.
 
         Supported formats: -latex, -brief, -rest
         """
 
         mode = ''
         try:
             mode = parameter_s.split()[0][1:]
             if mode == 'rest':
                 rest_docs = []
-        except:
+        except IndexError:
             pass
 
         magic_docs = []
         escapes = dict(line=ESC_MAGIC, cell=ESC_MAGIC*2)
         magics = self.shell.magics_manager.magics
 
         for mtype in ('line', 'cell'):
             escape = escapes[mtype]
             for fname, fn in magics[mtype].iteritems():
 
                 if mode == 'brief':
                     # only first line
                     if fn.__doc__:
                         fndoc = fn.__doc__.split('\n',1)[0]
                     else:
                         fndoc = 'No documentation'
                 else:
                     if fn.__doc__:
                         fndoc = fn.__doc__.rstrip()
                     else:
                         fndoc = 'No documentation'
 
                 if mode == 'rest':
                     rest_docs.append('**%s%s**::\n\n\t%s\n\n' %
                                      (escape, fname, fndoc))
                 else:
                     magic_docs.append('%s%s:\n\t%s\n' %
                                       (escape, fname, fndoc))
 
         magic_docs = ''.join(magic_docs)
 
         if mode == 'rest':
             return "".join(rest_docs)
 
         if mode == 'latex':
             print(self.format_latex(magic_docs))
             return
         else:
             magic_docs = format_screen(magic_docs)
         if mode == 'brief':
             return magic_docs
 
         out = ["""
 IPython's 'magic' functions
 ===========================
 
 The magic function system provides a series of functions which allow you to
 control the behavior of IPython itself, plus a lot of system-type
 features. All these functions are prefixed with a % character, but parameters
 are given without parentheses or quotes.
 
 NOTE: If you have 'automagic' enabled (via the command line option or with the
 %automagic function), you don't need to type in the % explicitly.  By default,
 IPython ships with automagic on, so you should only rarely need the % escape.
 
 Example: typing '%cd mydir' (without the quotes) changes you working directory
 to 'mydir', if it exists.
 
 For a list of the available magic functions, use %lsmagic. For a description
 of any of them, type %magic_name?, e.g. '%cd?'.
 
 Currently the magic system has the following functions:""",
        magic_docs,
        "Summary of magic functions (from %slsmagic):",
        self._lsmagic(),
        ]
         page.page('\n'.join(out))
 
 
     @line_magic
     def page(self, parameter_s=''):
         """Pretty print the object and display it through a pager.
 
         %page [options] OBJECT
 
         If no object is given, use _ (last output).
 
         Options:
 
           -r: page str(object), don't pretty-print it."""
 
         # After a function contributed by Olivier Aubert, slightly modified.
 
         # Process options/args
         opts, args = self.parse_options(parameter_s, 'r')
         raw = 'r' in opts
 
         oname = args and args or '_'
         info = self._ofind(oname)
         if info['found']:
             txt = (raw and str or pformat)( info['obj'] )
             page.page(txt)
         else:
             print('Object `%s` not found' % oname)
 
     @line_magic
     def profile(self, parameter_s=''):
         """Print your currently active IPython profile."""
         from IPython.core.application import BaseIPythonApplication
         if BaseIPythonApplication.initialized():
             print(BaseIPythonApplication.instance().profile)
         else:
             error("profile is an application-level value, but you don't appear to be in an IPython application")
 
     @line_magic
     def pprint(self, parameter_s=''):
         """Toggle pretty printing on/off."""
         ptformatter = self.shell.display_formatter.formatters['text/plain']
         ptformatter.pprint = bool(1 - ptformatter.pprint)
         print('Pretty printing has been turned',
               ['OFF','ON'][ptformatter.pprint])
 
     @line_magic
     def colors(self, parameter_s=''):
         """Switch color scheme for prompts, info system and exception handlers.
 
         Currently implemented schemes: NoColor, Linux, LightBG.
 
         Color scheme names are not case-sensitive.
 
         Examples
         --------
         To get a plain black and white terminal::
 
           %colors nocolor
         """
         def color_switch_err(name):
             warn('Error changing %s color schemes.\n%s' %
                  (name, sys.exc_info()[1]))
 
 
         new_scheme = parameter_s.strip()
         if not new_scheme:
             raise UsageError(
                 "%colors: you must specify a color scheme. See '%colors?'")
             return
         # local shortcut
         shell = self.shell
 
         import IPython.utils.rlineimpl as readline
 
         if not shell.colors_force and \
                 not readline.have_readline and sys.platform == "win32":
             msg = """\
 Proper color support under MS Windows requires the pyreadline library.
 You can find it at:
 http://ipython.org/pyreadline.html
 Gary's readline needs the ctypes module, from:
 http://starship.python.net/crew/theller/ctypes
 (Note that ctypes is already part of Python versions 2.5 and newer).
 
 Defaulting color scheme to 'NoColor'"""
             new_scheme = 'NoColor'
             warn(msg)
 
         # readline option is 0
         if not shell.colors_force and not shell.has_readline:
             new_scheme = 'NoColor'
 
         # Set prompt colors
         try:
             shell.prompt_manager.color_scheme = new_scheme
         except:
             color_switch_err('prompt')
         else:
             shell.colors = \
                    shell.prompt_manager.color_scheme_table.active_scheme_name
         # Set exception colors
         try:
             shell.InteractiveTB.set_colors(scheme = new_scheme)
             shell.SyntaxTB.set_colors(scheme = new_scheme)
         except:
             color_switch_err('exception')
 
         # Set info (for 'object?') colors
         if shell.color_info:
             try:
                 shell.inspector.set_active_scheme(new_scheme)
             except:
                 color_switch_err('object inspector')
         else:
             shell.inspector.set_active_scheme('NoColor')
 
     @line_magic
     def xmode(self, parameter_s=''):
         """Switch modes for the exception handlers.
 
         Valid modes: Plain, Context and Verbose.
 
         If called without arguments, acts as a toggle."""
 
         def xmode_switch_err(name):
             warn('Error changing %s exception modes.\n%s' %
                  (name,sys.exc_info()[1]))
 
         shell = self.shell
         new_mode = parameter_s.strip().capitalize()
         try:
             shell.InteractiveTB.set_mode(mode=new_mode)
             print('Exception reporting mode:',shell.InteractiveTB.mode)
         except:
             xmode_switch_err('user')
 
     @line_magic
     def quickref(self,arg):
         """ Show a quick reference sheet """
         from IPython.core.usage import quick_reference
         qr = quick_reference + self.magic('-brief')
         page.page(qr)
 
     @line_magic
     def doctest_mode(self, parameter_s=''):
         """Toggle doctest mode on and off.
 
         This mode is intended to make IPython behave as much as possible like a
         plain Python shell, from the perspective of how its prompts, exceptions
         and output look.  This makes it easy to copy and paste parts of a
         session into doctests.  It does so by:
 
         - Changing the prompts to the classic ``>>>`` ones.
         - Changing the exception reporting mode to 'Plain'.
         - Disabling pretty-printing of output.
 
         Note that IPython also supports the pasting of code snippets that have
         leading '>>>' and '...' prompts in them.  This means that you can paste
         doctests from files or docstrings (even if they have leading
         whitespace), and the code will execute correctly.  You can then use
         '%history -t' to see the translated history; this will give you the
         input after removal of all the leading prompts and whitespace, which
         can be pasted back into an editor.
 
         With these features, you can switch into this mode easily whenever you
         need to do testing and changes to doctests, without having to leave
         your existing IPython session.
         """
 
         # Shorthands
         shell = self.shell
         pm = shell.prompt_manager
         meta = shell.meta
         disp_formatter = self.shell.display_formatter
         ptformatter = disp_formatter.formatters['text/plain']
         # dstore is a data store kept in the instance metadata bag to track any
         # changes we make, so we can undo them later.
         dstore = meta.setdefault('doctest_mode',Struct())
         save_dstore = dstore.setdefault
 
         # save a few values we'll need to recover later
         mode = save_dstore('mode',False)
         save_dstore('rc_pprint',ptformatter.pprint)
         save_dstore('xmode',shell.InteractiveTB.mode)
         save_dstore('rc_separate_out',shell.separate_out)
         save_dstore('rc_separate_out2',shell.separate_out2)
         save_dstore('rc_prompts_pad_left',pm.justify)
         save_dstore('rc_separate_in',shell.separate_in)
         save_dstore('rc_plain_text_only',disp_formatter.plain_text_only)
         save_dstore('prompt_templates',(pm.in_template, pm.in2_template, pm.out_template))
 
         if mode == False:
             # turn on
             pm.in_template = '>>> '
             pm.in2_template = '... '
             pm.out_template = ''
 
             # Prompt separators like plain python
             shell.separate_in = ''
             shell.separate_out = ''
             shell.separate_out2 = ''
 
             pm.justify = False
 
             ptformatter.pprint = False
             disp_formatter.plain_text_only = True
 
             shell.magic('xmode Plain')
         else:
             # turn off
             pm.in_template, pm.in2_template, pm.out_template = dstore.prompt_templates
 
             shell.separate_in = dstore.rc_separate_in
 
             shell.separate_out = dstore.rc_separate_out
             shell.separate_out2 = dstore.rc_separate_out2
 
             pm.justify = dstore.rc_prompts_pad_left
 
             ptformatter.pprint = dstore.rc_pprint
             disp_formatter.plain_text_only = dstore.rc_plain_text_only
 
             shell.magic('xmode ' + dstore.xmode)
 
         # Store new mode and inform
         dstore.mode = bool(1-int(mode))
         mode_label = ['OFF','ON'][dstore.mode]
         print('Doctest mode is:', mode_label)
 
     @line_magic
     def gui(self, parameter_s=''):
         """Enable or disable IPython GUI event loop integration.
 
         %gui [GUINAME]
 
         This magic replaces IPython's threaded shells that were activated
         using the (pylab/wthread/etc.) command line flags.  GUI toolkits
         can now be enabled at runtime and keyboard
         interrupts should work without any problems.  The following toolkits
         are supported:  wxPython, PyQt4, PyGTK, Tk and Cocoa (OSX)::
 
             %gui wx      # enable wxPython event loop integration
             %gui qt4|qt  # enable PyQt4 event loop integration
             %gui gtk     # enable PyGTK event loop integration
             %gui gtk3    # enable Gtk3 event loop integration
             %gui tk      # enable Tk event loop integration
             %gui OSX     # enable Cocoa event loop integration
                          # (requires %matplotlib 1.1)
             %gui         # disable all event loop integration
 
         WARNING:  after any of these has been called you can simply create
         an application object, but DO NOT start the event loop yourself, as
         we have already handled that.
         """
         opts, arg = self.parse_options(parameter_s, '')
         if arg=='': arg = None
         try:
             return self.enable_gui(arg)
         except Exception as e:
             # print simple error message, rather than traceback if we can't
             # hook up the GUI
             error(str(e))
 
     @skip_doctest
     @line_magic
     def precision(self, s=''):
         """Set floating point precision for pretty printing.
 
         Can set either integer precision or a format string.
 
         If numpy has been imported and precision is an int,
         numpy display precision will also be set, via ``numpy.set_printoptions``.
 
         If no argument is given, defaults will be restored.
 
         Examples
         --------
         ::
 
             In [1]: from math import pi
 
             In [2]: %precision 3
             Out[2]: u'%.3f'
 
             In [3]: pi
             Out[3]: 3.142
 
             In [4]: %precision %i
             Out[4]: u'%i'
 
             In [5]: pi
             Out[5]: 3
 
             In [6]: %precision %e
             Out[6]: u'%e'
 
             In [7]: pi**10
             Out[7]: 9.364805e+04
 
             In [8]: %precision
             Out[8]: u'%r'
 
             In [9]: pi**10
             Out[9]: 93648.047476082982
         """
         ptformatter = self.shell.display_formatter.formatters['text/plain']
         ptformatter.float_precision = s
         return ptformatter.float_format
 
     @magic_arguments.magic_arguments()
     @magic_arguments.argument(
         '-e', '--export', action='store_true', default=False,
         help='Export IPython history as a notebook. The filename argument '
              'is used to specify the notebook name and format. For example '
              'a filename of notebook.ipynb will result in a notebook name '
              'of "notebook" and a format of "xml". Likewise using a ".json" '
              'or ".py" file extension will write the notebook in the json '
              'or py formats.'
     )
     @magic_arguments.argument(
         '-f', '--format',
         help='Convert an existing IPython notebook to a new format. This option '
              'specifies the new format and can have the values: xml, json, py. '
              'The target filename is chosen automatically based on the new '
              'format. The filename argument gives the name of the source file.'
     )
     @magic_arguments.argument(
         'filename', type=unicode,
         help='Notebook name or filename'
     )
     @line_magic
     def notebook(self, s):
         """Export and convert IPython notebooks.
 
         This function can export the current IPython history to a notebook file
         or can convert an existing notebook file into a different format. For
         example, to export the history to "foo.ipynb" do "%notebook -e foo.ipynb".
         To export the history to "foo.py" do "%notebook -e foo.py". To convert
         "foo.ipynb" to "foo.json" do "%notebook -f json foo.ipynb". Possible
         formats include (json/ipynb, py).
         """
         args = magic_arguments.parse_argstring(self.notebook, s)
 
         from IPython.nbformat import current
         args.filename = unquote_filename(args.filename)
         if args.export:
             fname, name, format = current.parse_filename(args.filename)
             cells = []
             hist = list(self.shell.history_manager.get_range())
             for session, prompt_number, input in hist[:-1]:
                 cells.append(current.new_code_cell(prompt_number=prompt_number,
                                                    input=input))
             worksheet = current.new_worksheet(cells=cells)
             nb = current.new_notebook(name=name,worksheets=[worksheet])
             with io.open(fname, 'w', encoding='utf-8') as f:
                 current.write(nb, f, format);
         elif args.format is not None:
             old_fname, old_name, old_format = current.parse_filename(args.filename)
             new_format = args.format
             if new_format == u'xml':
                 raise ValueError('Notebooks cannot be written as xml.')
             elif new_format == u'ipynb' or new_format == u'json':
                 new_fname = old_name + u'.ipynb'
                 new_format = u'json'
             elif new_format == u'py':
                 new_fname = old_name + u'.py'
             else:
                 raise ValueError('Invalid notebook format: %s' % new_format)
             with io.open(old_fname, 'r', encoding='utf-8') as f:
                 nb = current.read(f, old_format)
             with io.open(new_fname, 'w', encoding='utf-8') as f:
                 current.write(nb, f, new_format)

IPython/core/magics/code.py

@@ -1,478 +1,478 b''
 """Implementation of code management magic functions.
 """
 #-----------------------------------------------------------------------------
 #  Copyright (c) 2012 The 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
 #-----------------------------------------------------------------------------
 
 # Stdlib
 import inspect
 import io
 import json
 import os
 import sys
 from urllib2 import urlopen
 
 # Our own packages
 from IPython.core.error import TryNext
 from IPython.core.macro import Macro
 from IPython.core.magic import Magics, magics_class, line_magic
 from IPython.testing.skipdoctest import skip_doctest
 from IPython.utils import openpy
 from IPython.utils import py3compat
 from IPython.utils.io import file_read
 from IPython.utils.path import get_py_filename, unquote_filename
 from IPython.utils.warn import warn
 
 #-----------------------------------------------------------------------------
 # Magic implementation classes
 #-----------------------------------------------------------------------------
 
 # Used for exception handling in magic_edit
 class MacroToEdit(ValueError): pass
 
 
 @magics_class
 class CodeMagics(Magics):
     """Magics related to code management (loading, saving, editing, ...)."""
 
     @line_magic
     def save(self, parameter_s=''):
         """Save a set of lines or a macro to a given filename.
 
         Usage:\\
           %save [options] filename n1-n2 n3-n4 ... n5 .. n6 ...
 
         Options:
 
           -r: use 'raw' input.  By default, the 'processed' history is used,
           so that magics are loaded in their transformed version to valid
           Python.  If this option is given, the raw input as typed as the
           command line is used instead.
 
         This function uses the same syntax as %history for input ranges,
         then saves the lines to the filename you specify.
 
         It adds a '.py' extension to the file if you don't do so yourself, and
         it asks for confirmation before overwriting existing files."""
 
         opts,args = self.parse_options(parameter_s,'r',mode='list')
         fname, codefrom = unquote_filename(args[0]), " ".join(args[1:])
         if not fname.endswith('.py'):
             fname += '.py'
         if os.path.isfile(fname):
             ans = raw_input('File `%s` exists. Overwrite (y/[N])? ' % fname)
             if ans.lower() not in ['y','yes']:
                 print 'Operation cancelled.'
                 return
         try:
             cmds = self.shell.find_user_code(codefrom, 'r' in opts)
         except (TypeError, ValueError) as e:
             print e.args[0]
             return
         with io.open(fname,'w', encoding="utf-8") as f:
             f.write(u"# coding: utf-8\n")
             f.write(py3compat.cast_unicode(cmds))
         print 'The following commands were written to file `%s`:' % fname
         print cmds
 
     @line_magic
     def pastebin(self, parameter_s=''):
         """Upload code to Github's Gist paste bin, returning the URL.
 
         Usage:\\
           %pastebin [-d "Custom description"] 1-7
 
         The argument can be an input history range, a filename, or the name of a
         string or macro.
 
         Options:
 
           -d: Pass a custom description for the gist. The default will say
               "Pasted from IPython".
         """
         opts, args = self.parse_options(parameter_s, 'd:')
 
         try:
             code = self.shell.find_user_code(args)
         except (ValueError, TypeError) as e:
             print e.args[0]
             return
 
         post_data = json.dumps({
           "description": opts.get('d', "Pasted from IPython"),
           "public": True,
           "files": {
             "file1.py": {
               "content": code
             }
           }
         }).encode('utf-8')
 
         response = urlopen("https://api.github.com/gists", post_data)
         response_data = json.loads(response.read().decode('utf-8'))
         return response_data['html_url']
 
     @line_magic
     def loadpy(self, arg_s):
         """Load a .py python script into the GUI console.
 
         This magic command can either take a local filename or a url::
 
         %loadpy myscript.py
         %loadpy http://www.example.com/myscript.py
         """
         arg_s = unquote_filename(arg_s)
         remote_url = arg_s.startswith(('http://', 'https://'))
         local_url = not remote_url
         if local_url and not arg_s.endswith('.py'):
             # Local files must be .py; for remote URLs it's possible that the
             # fetch URL doesn't have a .py in it (many servers have an opaque
             # URL, such as scipy-central.org).
             raise ValueError('%%loadpy only works with .py files: %s' % arg_s)
 
         # openpy takes care of finding the source encoding (per PEP 263)
         if remote_url:
             contents = openpy.read_py_url(arg_s, skip_encoding_cookie=True)
         else:
             contents = openpy.read_py_file(arg_s, skip_encoding_cookie=True)
 
         self.shell.set_next_input(contents)
 
     def _find_edit_target(self, args, opts, last_call):
         """Utility method used by magic_edit to find what to edit."""
 
         def make_filename(arg):
             "Make a filename from the given args"
             arg = unquote_filename(arg)
             try:
                 filename = get_py_filename(arg)
             except IOError:
                 # If it ends with .py but doesn't already exist, assume we want
                 # a new file.
                 if arg.endswith('.py'):
                     filename = arg
                 else:
                     filename = None
             return filename
 
         # Set a few locals from the options for convenience:
         opts_prev = 'p' in opts
         opts_raw = 'r' in opts
 
         # custom exceptions
         class DataIsObject(Exception): pass
 
         # Default line number value
         lineno = opts.get('n',None)
 
         if opts_prev:
             args = '_%s' % last_call[0]
             if not self.shell.user_ns.has_key(args):
                 args = last_call[1]
 
         # use last_call to remember the state of the previous call, but don't
         # let it be clobbered by successive '-p' calls.
         try:
             last_call[0] = self.shell.displayhook.prompt_count
             if not opts_prev:
                 last_call[1] = args
         except:
             pass
 
         # by default this is done with temp files, except when the given
         # arg is a filename
         use_temp = True
 
         data = ''
 
         # First, see if the arguments should be a filename.
         filename = make_filename(args)
         if filename:
             use_temp = False
         elif args:
             # Mode where user specifies ranges of lines, like in %macro.
             data = self.shell.extract_input_lines(args, opts_raw)
             if not data:
                 try:
                     # Load the parameter given as a variable. If not a string,
                     # process it as an object instead (below)
 
                     #print '*** args',args,'type',type(args)  # dbg
                     data = eval(args, self.shell.user_ns)
                     if not isinstance(data, basestring):
                         raise DataIsObject
 
                 except (NameError,SyntaxError):
                     # given argument is not a variable, try as a filename
                     filename = make_filename(args)
                     if filename is None:
                         warn("Argument given (%s) can't be found as a variable "
                              "or as a filename." % args)
                         return
                     use_temp = False
 
                 except DataIsObject:
                     # macros have a special edit function
                     if isinstance(data, Macro):
                         raise MacroToEdit(data)
 
                     # For objects, try to edit the file where they are defined
                     try:
                         filename = inspect.getabsfile(data)
                         if 'fakemodule' in filename.lower() and \
                             inspect.isclass(data):
                             # class created by %edit? Try to find source
                             # by looking for method definitions instead, the
                             # __module__ in those classes is FakeModule.
                             attrs = [getattr(data, aname) for aname in dir(data)]
                             for attr in attrs:
                                 if not inspect.ismethod(attr):
                                     continue
                                 filename = inspect.getabsfile(attr)
                                 if filename and \
                                   'fakemodule' not in filename.lower():
                                     # change the attribute to be the edit
                                     # target instead
                                     data = attr
                                     break
 
                         datafile = 1
                     except TypeError:
                         filename = make_filename(args)
                         datafile = 1
                         warn('Could not find file where `%s` is defined.\n'
                              'Opening a file named `%s`' % (args,filename))
                     # Now, make sure we can actually read the source (if it was
                     # in a temp file it's gone by now).
                     if datafile:
                         try:
                             if lineno is None:
                                 lineno = inspect.getsourcelines(data)[1]
                         except IOError:
                             filename = make_filename(args)
                             if filename is None:
-                                warn('The file `%s` where `%s` was defined cannot '
-                                     'be read.' % (filename,data))
+                                warn('The file `%s` where `%s` was defined '
+                                     'cannot be read.' % (filename, data))
                                 return
                     use_temp = False
 
         if use_temp:
             filename = self.shell.mktempfile(data)
             print 'IPython will make a temporary file named:',filename
 
         return filename, lineno, use_temp
 
     def _edit_macro(self,mname,macro):
         """open an editor with the macro data in a file"""
         filename = self.shell.mktempfile(macro.value)
         self.shell.hooks.editor(filename)
 
         # and make a new macro object, to replace the old one
         mfile = open(filename)
         mvalue = mfile.read()
         mfile.close()
         self.shell.user_ns[mname] = Macro(mvalue)
 
     @line_magic
     def ed(self, parameter_s=''):
         """Alias to %edit."""
         return self.edit(parameter_s)
 
     @skip_doctest
     @line_magic
     def edit(self, parameter_s='',last_call=['','']):
         """Bring up an editor and execute the resulting code.
 
         Usage:
           %edit [options] [args]
 
         %edit runs IPython's editor hook. The default version of this hook is
         set to call the editor specified by your $EDITOR environment variable.
         If this isn't found, it will default to vi under Linux/Unix and to
         notepad under Windows. See the end of this docstring for how to change
         the editor hook.
 
         You can also set the value of this editor via the
         ``TerminalInteractiveShell.editor`` option in your configuration file.
         This is useful if you wish to use a different editor from your typical
         default with IPython (and for Windows users who typically don't set
         environment variables).
 
         This command allows you to conveniently edit multi-line code right in
         your IPython session.
 
         If called without arguments, %edit opens up an empty editor with a
         temporary file and will execute the contents of this file when you
         close it (don't forget to save it!).
 
 
         Options:
 
         -n <number>: open the editor at a specified line number.  By default,
         the IPython editor hook uses the unix syntax 'editor +N filename', but
         you can configure this by providing your own modified hook if your
         favorite editor supports line-number specifications with a different
         syntax.
 
         -p: this will call the editor with the same data as the previous time
         it was used, regardless of how long ago (in your current session) it
         was.
 
         -r: use 'raw' input.  This option only applies to input taken from the
         user's history.  By default, the 'processed' history is used, so that
         magics are loaded in their transformed version to valid Python.  If
         this option is given, the raw input as typed as the command line is
         used instead.  When you exit the editor, it will be executed by
         IPython's own processor.
 
         -x: do not execute the edited code immediately upon exit. This is
         mainly useful if you are editing programs which need to be called with
         command line arguments, which you can then do using %run.
 
 
         Arguments:
 
         If arguments are given, the following possibilities exist:
 
         - If the argument is a filename, IPython will load that into the
           editor. It will execute its contents with execfile() when you exit,
           loading any code in the file into your interactive namespace.
 
         - The arguments are ranges of input history,  e.g. "7 ~1/4-6".
           The syntax is the same as in the %history magic.
 
         - If the argument is a string variable, its contents are loaded
           into the editor. You can thus edit any string which contains
           python code (including the result of previous edits).
 
         - If the argument is the name of an object (other than a string),
           IPython will try to locate the file where it was defined and open the
           editor at the point where it is defined. You can use `%edit function`
           to load an editor exactly at the point where 'function' is defined,
           edit it and have the file be executed automatically.
 
         - If the object is a macro (see %macro for details), this opens up your
           specified editor with a temporary file containing the macro's data.
           Upon exit, the macro is reloaded with the contents of the file.
 
         Note: opening at an exact line is only supported under Unix, and some
         editors (like kedit and gedit up to Gnome 2.8) do not understand the
         '+NUMBER' parameter necessary for this feature. Good editors like
         (X)Emacs, vi, jed, pico and joe all do.
 
         After executing your code, %edit will return as output the code you
         typed in the editor (except when it was an existing file). This way
         you can reload the code in further invocations of %edit as a variable,
         via _<NUMBER> or Out[<NUMBER>], where <NUMBER> is the prompt number of
         the output.
 
         Note that %edit is also available through the alias %ed.
 
         This is an example of creating a simple function inside the editor and
         then modifying it. First, start up the editor::
 
           In [1]: ed
           Editing... done. Executing edited code...
           Out[1]: 'def foo():\\n    print "foo() was defined in an editing
           session"\\n'
 
         We can then call the function foo()::
 
           In [2]: foo()
           foo() was defined in an editing session
 
         Now we edit foo.  IPython automatically loads the editor with the
         (temporary) file where foo() was previously defined::
 
           In [3]: ed foo
           Editing... done. Executing edited code...
 
         And if we call foo() again we get the modified version::
 
           In [4]: foo()
           foo() has now been changed!
 
         Here is an example of how to edit a code snippet successive
         times. First we call the editor::
 
           In [5]: ed
           Editing... done. Executing edited code...
           hello
           Out[5]: "print 'hello'\\n"
 
         Now we call it again with the previous output (stored in _)::
 
           In [6]: ed _
           Editing... done. Executing edited code...
           hello world
           Out[6]: "print 'hello world'\\n"
 
         Now we call it with the output #8 (stored in _8, also as Out[8])::
 
           In [7]: ed _8
           Editing... done. Executing edited code...
           hello again
           Out[7]: "print 'hello again'\\n"
 
 
         Changing the default editor hook:
 
         If you wish to write your own editor hook, you can put it in a
         configuration file which you load at startup time.  The default hook
         is defined in the IPython.core.hooks module, and you can use that as a
         starting example for further modifications.  That file also has
         general instructions on how to set a new hook for use once you've
         defined it."""
         opts,args = self.parse_options(parameter_s,'prxn:')
 
         try:
             filename, lineno, is_temp = self._find_edit_target(args, opts, last_call)
         except MacroToEdit as e:
             self._edit_macro(args, e.args[0])
             return
 
         # do actual editing here
         print 'Editing...',
         sys.stdout.flush()
         try:
             # Quote filenames that may have spaces in them
             if ' ' in filename:
                 filename = "'%s'" % filename
             self.shell.hooks.editor(filename,lineno)
         except TryNext:
             warn('Could not open editor')
             return
 
         # XXX TODO: should this be generalized for all string vars?
         # For now, this is special-cased to blocks created by cpaste
         if args.strip() == 'pasted_block':
             self.shell.user_ns['pasted_block'] = file_read(filename)
 
         if 'x' in opts:  # -x prevents actual execution
             print
         else:
             print 'done. Executing edited code...'
             if 'r' in opts:    # Untranslated IPython code
                 self.shell.run_cell(file_read(filename),
                                                     store_history=False)
             else:
                 self.shell.safe_execfile(filename, self.shell.user_ns,
                                          self.shell.user_ns)
 
         if is_temp:
             try:
                 return open(filename).read()
             except IOError,msg:
                 if msg.filename == filename:
                     warn('File not found. Did you forget to save?')
                     return
                 else:
                     self.shell.showtraceback()