"""Magic functions for InteractiveShell.
"""

#-----------------------------------------------------------------------------
#  Copyright (C) 2001 Janko Hauser <jhauser@zscout.de> and
#  Copyright (C) 2001 Fernando Perez <fperez@colorado.edu>
#  Copyright (C) 2008 The IPython Development Team

#  Distributed under the terms of the BSD License.  The full license is in
#  the file COPYING, distributed as part of this software.
#-----------------------------------------------------------------------------
#-----------------------------------------------------------------------------
# Imports
#-----------------------------------------------------------------------------

import __builtin__ as builtin_mod
import bdb
import gc
import inspect
import io
import json
import os
import re
import sys
import time
from StringIO import StringIO
from pprint import pformat
from urllib2 import urlopen

# cProfile was added in Python2.5
try:
    import cProfile as profile
    import pstats
except ImportError:
    # profile isn't bundled by default in Debian for license reasons
    try:
        import profile, pstats
    except ImportError:
        profile = pstats = None

from IPython.config.application import Application
from IPython.core import debugger, oinspect
from IPython.core import magic_arguments, page
from IPython.core.error import UsageError, StdinNotImplementedError, TryNext
from IPython.core.macro import Macro
from IPython.core.magic import (Bunch, Magics, compress_dhist,
                                on_off, needs_local_scope,
                                register_magics, line_magic, cell_magic)
from IPython.core.prefilter import ESC_MAGIC
from IPython.testing.skipdoctest import skip_doctest
from IPython.utils import openpy
from IPython.utils import py3compat
from IPython.utils.encoding import DEFAULT_ENCODING
from IPython.utils.io import file_read, nlprint
from IPython.utils.ipstruct import Struct
from IPython.utils.module_paths import find_mod
from IPython.utils.path import get_py_filename, unquote_filename
from IPython.utils.process import abbrev_cwd
from IPython.utils.terminal import set_term_title
from IPython.utils.text import format_screen
from IPython.utils.timing import clock, clock2
from IPython.utils.warn import warn, error

#-----------------------------------------------------------------------------
# Magic implementation classes
#-----------------------------------------------------------------------------

@register_magics
class UserMagics(Magics):
    """Placeholder for user-defined magics to be added at runtime.

    All magics are eventually merged into a single namespace at runtime, but we
    use this class to isolate the magics defined dynamically by the user into
    their own class.
    """


@register_magics
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:
            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)


# Used for exception handling in magic_edit
class MacroToEdit(ValueError): pass


@register_magics
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.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))
                                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.magic_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()


@register_magics
class ConfigMagics(Magics):

    def __init__(self, shell):
        super(ConfigMagics, self).__init__(shell)
        self.configurables = []

    @line_magic
    def config(self, s):
        """configure IPython

            %config Class[.trait=value]

        This magic exposes most of the IPython config system. Any
        Configurable class should be able to be configured with the simple
        line::

            %config Class.trait=value

        Where `value` will be resolved in the user's namespace, if it is an
        expression or variable name.

        Examples
        --------

        To see what classes are available for config, pass no arguments::

            In [1]: %config
            Available objects for config:
                TerminalInteractiveShell
                HistoryManager
                PrefilterManager
                AliasManager
                IPCompleter
                PromptManager
                DisplayFormatter

        To view what is configurable on a given class, just pass the class
        name::

            In [2]: %config IPCompleter
            IPCompleter options
            -----------------
            IPCompleter.omit__names=<Enum>
                Current: 2
                Choices: (0, 1, 2)
                Instruct the completer to omit private method names
                Specifically, when completing on ``object.<tab>``.
                When 2 [default]: all names that start with '_' will be excluded.
                When 1: all 'magic' names (``__foo__``) will be excluded.
                When 0: nothing will be excluded.
            IPCompleter.merge_completions=<CBool>
                Current: True
                Whether to merge completion results into a single list
                If False, only the completion results from the first non-empty completer
                will be returned.
            IPCompleter.limit_to__all__=<CBool>
                Current: False
                Instruct the completer to use __all__ for the completion
                Specifically, when completing on ``object.<tab>``.
                When True: only those names in obj.__all__ will be included.
                When False [default]: the __all__ attribute is ignored
            IPCompleter.greedy=<CBool>
                Current: False
                Activate greedy completion
                This will enable completion on elements of lists, results of function calls,
                etc., but can be unsafe because the code is actually evaluated on TAB.

        but the real use is in setting values::

            In [3]: %config IPCompleter.greedy = True

        and these values are read from the user_ns if they are variables::

            In [4]: feeling_greedy=False

            In [5]: %config IPCompleter.greedy = feeling_greedy

        """
        from IPython.config.loader import Config
        # some IPython objects are Configurable, but do not yet have
        # any configurable traits.  Exclude them from the effects of
        # this magic, as their presence is just noise:
        configurables = [ c for c in self.shell.configurables
                          if c.__class__.class_traits(config=True) ]
        classnames = [ c.__class__.__name__ for c in configurables ]

        line = s.strip()
        if not line:
            # print available configurable names
            print "Available objects for config:"
            for name in classnames:
                print "    ", name
            return
        elif line in classnames:
            # `%config TerminalInteractiveShell` will print trait info for
            # TerminalInteractiveShell
            c = configurables[classnames.index(line)]
            cls = c.__class__
            help = cls.class_get_help(c)
            # strip leading '--' from cl-args:
            help = re.sub(re.compile(r'^--', re.MULTILINE), '', help)
            print help
            return
        elif '=' not in line:
            raise UsageError("Invalid config statement: %r, should be Class.trait = value" % line)


        # otherwise, assume we are setting configurables.
        # leave quotes on args when splitting, because we want
        # unquoted args to eval in user_ns
        cfg = Config()
        exec "cfg."+line in locals(), self.shell.user_ns

        for configurable in configurables:
            try:
                configurable.update_config(cfg)
            except Exception as e:
                error(e)


@register_magics
class NamespaceMagics(Magics):
    """Magics to manage various aspects of the user's namespace.

    These include listing variables, introspecting into them, etc.
    """

    @line_magic
    def pinfo(self, parameter_s='', namespaces=None):
        """Provide detailed information about an object.

        '%pinfo object' is just a synonym for object? or ?object."""

        #print 'pinfo par: <%s>' % parameter_s  # dbg


        # detail_level: 0 -> obj? , 1 -> obj??
        detail_level = 0
        # We need to detect if we got called as 'pinfo pinfo foo', which can
        # happen if the user types 'pinfo foo?' at the cmd line.
        pinfo,qmark1,oname,qmark2 = \
               re.match('(pinfo )?(\?*)(.*?)(\??$)',parameter_s).groups()
        if pinfo or qmark1 or qmark2:
            detail_level = 1
        if "*" in oname:
            self.psearch(oname)
        else:
            self.shell._inspect('pinfo', oname, detail_level=detail_level,
                                namespaces=namespaces)

    @line_magic
    def pinfo2(self, parameter_s='', namespaces=None):
        """Provide extra detailed information about an object.

        '%pinfo2 object' is just a synonym for object?? or ??object."""
        self.shell._inspect('pinfo', parameter_s, detail_level=1,
                            namespaces=namespaces)

    @skip_doctest
    @line_magic
    def pdef(self, parameter_s='', namespaces=None):
        """Print the definition header for any callable object.

        If the object is a class, print the constructor information.

        Examples
        --------
        ::

          In [3]: %pdef urllib.urlopen
          urllib.urlopen(url, data=None, proxies=None)
        """
        self._inspect('pdef',parameter_s, namespaces)

    @line_magic
    def pdoc(self, parameter_s='', namespaces=None):
        """Print the docstring for an object.

        If the given object is a class, it will print both the class and the
        constructor docstrings."""
        self._inspect('pdoc',parameter_s, namespaces)

    @line_magic
    def psource(self, parameter_s='', namespaces=None):
        """Print (or run through pager) the source code for an object."""
        self._inspect('psource',parameter_s, namespaces)

    @line_magic
    def pfile(self, parameter_s=''):
        """Print (or run through pager) the file where an object is defined.

        The file opens at the line where the object definition begins. IPython
        will honor the environment variable PAGER if set, and otherwise will
        do its best to print the file in a convenient form.

        If the given argument is not an object currently defined, IPython will
        try to interpret it as a filename (automatically adding a .py extension
        if needed). You can thus use %pfile as a syntax highlighting code
        viewer."""

        # first interpret argument as an object name
        out = self._inspect('pfile',parameter_s)
        # if not, try the input as a filename
        if out == 'not found':
            try:
                filename = get_py_filename(parameter_s)
            except IOError,msg:
                print msg
                return
            page.page(self.shell.inspector.format(open(filename).read()))

    @line_magic
    def psearch(self, parameter_s=''):
        """Search for object in namespaces by wildcard.

        %psearch [options] PATTERN [OBJECT TYPE]

        Note: ? can be used as a synonym for %psearch, at the beginning or at
        the end: both a*? and ?a* are equivalent to '%psearch a*'.  Still, the
        rest of the command line must be unchanged (options come first), so
        for example the following forms are equivalent

        %psearch -i a* function
        -i a* function?
        ?-i a* function

        Arguments:

          PATTERN

          where PATTERN is a string containing * as a wildcard similar to its
          use in a shell.  The pattern is matched in all namespaces on the
          search path. By default objects starting with a single _ are not
          matched, many IPython generated objects have a single
          underscore. The default is case insensitive matching. Matching is
          also done on the attributes of objects and not only on the objects
          in a module.

          [OBJECT TYPE]

          Is the name of a python type from the types module. The name is
          given in lowercase without the ending type, ex. StringType is
          written string. By adding a type here only objects matching the
          given type are matched. Using all here makes the pattern match all
          types (this is the default).

        Options:

          -a: makes the pattern match even objects whose names start with a
          single underscore.  These names are normally omitted from the
          search.

          -i/-c: make the pattern case insensitive/sensitive.  If neither of
          these options are given, the default is read from your configuration
          file, with the option ``InteractiveShell.wildcards_case_sensitive``.
          If this option is not specified in your configuration file, IPython's
          internal default is to do a case sensitive search.

          -e/-s NAMESPACE: exclude/search a given namespace.  The pattern you
          specify can be searched in any of the following namespaces:
          'builtin', 'user', 'user_global','internal', 'alias', where
          'builtin' and 'user' are the search defaults.  Note that you should
          not use quotes when specifying namespaces.

          'Builtin' contains the python module builtin, 'user' contains all
          user data, 'alias' only contain the shell aliases and no python
          objects, 'internal' contains objects used by IPython.  The
          'user_global' namespace is only used by embedded IPython instances,
          and it contains module-level globals.  You can add namespaces to the
          search with -s or exclude them with -e (these options can be given
          more than once).

        Examples
        --------
        ::

          %psearch a*            -> objects beginning with an a
          %psearch -e builtin a* -> objects NOT in the builtin space starting in a
          %psearch a* function   -> all functions beginning with an a
          %psearch re.e*         -> objects beginning with an e in module re
          %psearch r*.e*         -> objects that start with e in modules starting in r
          %psearch r*.* string   -> all strings in modules beginning with r

        Case sensitive search::

          %psearch -c a*         list all object beginning with lower case a

        Show objects beginning with a single _::

          %psearch -a _*         list objects beginning with a single underscore"""
        try:
            parameter_s.encode('ascii')
        except UnicodeEncodeError:
            print 'Python identifiers can only contain ascii characters.'
            return

        # default namespaces to be searched
        def_search = ['user_local', 'user_global', 'builtin']

        # Process options/args
        opts,args = self.parse_options(parameter_s,'cias:e:',list_all=True)
        opt = opts.get
        shell = self.shell
        psearch = shell.inspector.psearch

        # select case options
        if opts.has_key('i'):
            ignore_case = True
        elif opts.has_key('c'):
            ignore_case = False
        else:
            ignore_case = not shell.wildcards_case_sensitive

        # Build list of namespaces to search from user options
        def_search.extend(opt('s',[]))
        ns_exclude = ns_exclude=opt('e',[])
        ns_search = [nm for nm in def_search if nm not in ns_exclude]

        # Call the actual search
        try:
            psearch(args,shell.ns_table,ns_search,
                    show_all=opt('a'),ignore_case=ignore_case)
        except:
            shell.showtraceback()

    @skip_doctest
    @line_magic
    def who_ls(self, parameter_s=''):
        """Return a sorted list of all interactive variables.

        If arguments are given, only variables of types matching these
        arguments are returned.

        Examples
        --------

        Define two variables and list them with who_ls::

          In [1]: alpha = 123

          In [2]: beta = 'test'

          In [3]: %who_ls
          Out[3]: ['alpha', 'beta']

          In [4]: %who_ls int
          Out[4]: ['alpha']

          In [5]: %who_ls str
          Out[5]: ['beta']
        """

        user_ns = self.shell.user_ns
        user_ns_hidden = self.shell.user_ns_hidden
        out = [ i for i in user_ns
                if not i.startswith('_') \
                and not i in user_ns_hidden ]

        typelist = parameter_s.split()
        if typelist:
            typeset = set(typelist)
            out = [i for i in out if type(user_ns[i]).__name__ in typeset]

        out.sort()
        return out

    @skip_doctest
    @line_magic
    def who(self, parameter_s=''):
        """Print all interactive variables, with some minimal formatting.

        If any arguments are given, only variables whose type matches one of
        these are printed.  For example::

          %who function str

        will only list functions and strings, excluding all other types of
        variables.  To find the proper type names, simply use type(var) at a
        command line to see how python prints type names.  For example:

        ::

          In [1]: type('hello')\\
          Out[1]: <type 'str'>

        indicates that the type name for strings is 'str'.

        ``%who`` always excludes executed names loaded through your configuration
        file and things which are internal to IPython.

        This is deliberate, as typically you may load many modules and the
        purpose of %who is to show you only what you've manually defined.

        Examples
        --------

        Define two variables and list them with who::

          In [1]: alpha = 123

          In [2]: beta = 'test'

          In [3]: %who
          alpha   beta

          In [4]: %who int
          alpha

          In [5]: %who str
          beta
        """

        varlist = self.who_ls(parameter_s)
        if not varlist:
            if parameter_s:
                print 'No variables match your requested type.'
            else:
                print 'Interactive namespace is empty.'
            return

        # if we have variables, move on...
        count = 0
        for i in varlist:
            print i+'\t',
            count += 1
            if count > 8:
                count = 0
                print
        print

    @skip_doctest
    @line_magic
    def whos(self, parameter_s=''):
        """Like %who, but gives some extra information about each variable.

        The same type filtering of %who can be applied here.

        For all variables, the type is printed. Additionally it prints:

          - For {},[],(): their length.

          - For numpy arrays, a summary with shape, number of
          elements, typecode and size in memory.

          - Everything else: a string representation, snipping their middle if
          too long.

        Examples
        --------

        Define two variables and list them with whos::

          In [1]: alpha = 123

          In [2]: beta = 'test'

          In [3]: %whos
          Variable   Type        Data/Info
          --------------------------------
          alpha      int         123
          beta       str         test
        """

        varnames = self.who_ls(parameter_s)
        if not varnames:
            if parameter_s:
                print 'No variables match your requested type.'
            else:
                print 'Interactive namespace is empty.'
            return

        # if we have variables, move on...

        # for these types, show len() instead of data:
        seq_types = ['dict', 'list', 'tuple']

        # for numpy arrays, display summary info
        ndarray_type = None
        if 'numpy' in sys.modules:
            try:
                from numpy import ndarray
            except ImportError:
                pass
            else:
                ndarray_type = ndarray.__name__

        # Find all variable names and types so we can figure out column sizes
        def get_vars(i):
            return self.shell.user_ns[i]

        # some types are well known and can be shorter
        abbrevs = {'IPython.core.macro.Macro' : 'Macro'}
        def type_name(v):
            tn = type(v).__name__
            return abbrevs.get(tn,tn)

        varlist = map(get_vars,varnames)

        typelist = []
        for vv in varlist:
            tt = type_name(vv)

            if tt=='instance':
                typelist.append( abbrevs.get(str(vv.__class__),
                                             str(vv.__class__)))
            else:
                typelist.append(tt)

        # column labels and # of spaces as separator
        varlabel = 'Variable'
        typelabel = 'Type'
        datalabel = 'Data/Info'
        colsep = 3
        # variable format strings
        vformat    = "{0:<{varwidth}}{1:<{typewidth}}"
        aformat    = "%s: %s elems, type `%s`, %s bytes"
        # find the size of the columns to format the output nicely
        varwidth = max(max(map(len,varnames)), len(varlabel)) + colsep
        typewidth = max(max(map(len,typelist)), len(typelabel)) + colsep
        # table header
        print varlabel.ljust(varwidth) + typelabel.ljust(typewidth) + \
              ' '+datalabel+'\n' + '-'*(varwidth+typewidth+len(datalabel)+1)
        # and the table itself
        kb = 1024
        Mb = 1048576  # kb**2
        for vname,var,vtype in zip(varnames,varlist,typelist):
            print vformat.format(vname, vtype, varwidth=varwidth, typewidth=typewidth),
            if vtype in seq_types:
                print "n="+str(len(var))
            elif vtype == ndarray_type:
                vshape = str(var.shape).replace(',','').replace(' ','x')[1:-1]
                if vtype==ndarray_type:
                    # numpy
                    vsize  = var.size
                    vbytes = vsize*var.itemsize
                    vdtype = var.dtype

                if vbytes < 100000:
                    print aformat % (vshape,vsize,vdtype,vbytes)
                else:
                    print aformat % (vshape,vsize,vdtype,vbytes),
                    if vbytes < Mb:
                        print '(%s kb)' % (vbytes/kb,)
                    else:
                        print '(%s Mb)' % (vbytes/Mb,)
            else:
                try:
                    vstr = str(var)
                except UnicodeEncodeError:
                    vstr = unicode(var).encode(DEFAULT_ENCODING,
                                               'backslashreplace')
                except:
                    vstr = "<object with id %d (str() failed)>" % id(var)
                vstr = vstr.replace('\n','\\n')
                if len(vstr) < 50:
                    print vstr
                else:
                    print vstr[:25] + "<...>" + vstr[-25:]

    @line_magic
    def reset(self, parameter_s=''):
        """Resets the namespace by removing all names defined by the user, if
        called without arguments, or by removing some types of objects, such
        as everything currently in IPython's In[] and Out[] containers (see
        the parameters for details).

        Parameters
        ----------
        -f : force reset without asking for confirmation.

        -s : 'Soft' reset: Only clears your namespace, leaving history intact.
            References to objects may be kept. By default (without this option),
            we do a 'hard' reset, giving you a new session and removing all
            references to objects from the current session.

        in : reset input history

        out : reset output history

        dhist : reset directory history

        array : reset only variables that are NumPy arrays

        See Also
        --------
        magic_reset_selective : invoked as ``%reset_selective``

        Examples
        --------
        ::

          In [6]: a = 1

          In [7]: a
          Out[7]: 1

          In [8]: 'a' in _ip.user_ns
          Out[8]: True

          In [9]: %reset -f

          In [1]: 'a' in _ip.user_ns
          Out[1]: False

          In [2]: %reset -f in
          Flushing input history

          In [3]: %reset -f dhist in
          Flushing directory history
          Flushing input history

        Notes
        -----
        Calling this magic from clients that do not implement standard input,
        such as the ipython notebook interface, will reset the namespace
        without confirmation.
        """
        opts, args = self.parse_options(parameter_s,'sf', mode='list')
        if 'f' in opts:
            ans = True
        else:
            try:
                ans = self.shell.ask_yes_no(
                "Once deleted, variables cannot be recovered. Proceed (y/[n])? ", default='n')
            except StdinNotImplementedError:
                ans = True
        if not ans:
            print 'Nothing done.'
            return

        if 's' in opts:                     # Soft reset
            user_ns = self.shell.user_ns
            for i in self.magic_who_ls():
                del(user_ns[i])
        elif len(args) == 0:                # Hard reset
            self.shell.reset(new_session = False)

        # reset in/out/dhist/array: previously extensinions/clearcmd.py
        ip = self.shell
        user_ns = self.shell.user_ns  # local lookup, heavily used

        for target in args:
            target = target.lower() # make matches case insensitive
            if target == 'out':
                print "Flushing output cache (%d entries)" % len(user_ns['_oh'])
                self.shell.displayhook.flush()

            elif target == 'in':
                print "Flushing input history"
                pc = self.shell.displayhook.prompt_count + 1
                for n in range(1, pc):
                    key = '_i'+repr(n)
                    user_ns.pop(key,None)
                user_ns.update(dict(_i=u'',_ii=u'',_iii=u''))
                hm = ip.history_manager
                # don't delete these, as %save and %macro depending on the length
                # of these lists to be preserved
                hm.input_hist_parsed[:] = [''] * pc
                hm.input_hist_raw[:] = [''] * pc
                # hm has internal machinery for _i,_ii,_iii, clear it out
                hm._i = hm._ii = hm._iii = hm._i00 =  u''

            elif target == 'array':
                # Support cleaning up numpy arrays
                try:
                    from numpy import ndarray
                    # This must be done with items and not iteritems because we're
                    # going to modify the dict in-place.
                    for x,val in user_ns.items():
                        if isinstance(val,ndarray):
                            del user_ns[x]
                except ImportError:
                    print "reset array only works if Numpy is available."

            elif target == 'dhist':
                print "Flushing directory history"
                del user_ns['_dh'][:]

            else:
                print "Don't know how to reset ",
                print target + ", please run `%reset?` for details"

        gc.collect()

    @line_magic
    def reset_selective(self, parameter_s=''):
        """Resets the namespace by removing names defined by the user.

        Input/Output history are left around in case you need them.

        %reset_selective [-f] regex

        No action is taken if regex is not included

        Options
          -f : force reset without asking for confirmation.

        See Also
        --------
        magic_reset : invoked as ``%reset``

        Examples
        --------

        We first fully reset the namespace so your output looks identical to
        this example for pedagogical reasons; in practice you do not need a
        full reset::

          In [1]: %reset -f

        Now, with a clean namespace we can make a few variables and use
        ``%reset_selective`` to only delete names that match our regexp::

          In [2]: a=1; b=2; c=3; b1m=4; b2m=5; b3m=6; b4m=7; b2s=8

          In [3]: who_ls
          Out[3]: ['a', 'b', 'b1m', 'b2m', 'b2s', 'b3m', 'b4m', 'c']

          In [4]: %reset_selective -f b[2-3]m

          In [5]: who_ls
          Out[5]: ['a', 'b', 'b1m', 'b2s', 'b4m', 'c']

          In [6]: %reset_selective -f d

          In [7]: who_ls
          Out[7]: ['a', 'b', 'b1m', 'b2s', 'b4m', 'c']

          In [8]: %reset_selective -f c

          In [9]: who_ls
          Out[9]: ['a', 'b', 'b1m', 'b2s', 'b4m']

          In [10]: %reset_selective -f b

          In [11]: who_ls
          Out[11]: ['a']

        Notes
        -----
        Calling this magic from clients that do not implement standard input,
        such as the ipython notebook interface, will reset the namespace
        without confirmation.
        """

        opts, regex = self.parse_options(parameter_s,'f')

        if opts.has_key('f'):
            ans = True
        else:
            try:
                ans = self.shell.ask_yes_no(
                "Once deleted, variables cannot be recovered. Proceed (y/[n])? ",
                default='n')
            except StdinNotImplementedError:
                ans = True
        if not ans:
            print 'Nothing done.'
            return
        user_ns = self.shell.user_ns
        if not regex:
            print 'No regex pattern specified. Nothing done.'
            return
        else:
            try:
                m = re.compile(regex)
            except TypeError:
                raise TypeError('regex must be a string or compiled pattern')
            for i in self.magic_who_ls():
                if m.search(i):
                    del(user_ns[i])

    @line_magic
    def xdel(self, parameter_s=''):
        """Delete a variable, trying to clear it from anywhere that
        IPython's machinery has references to it. By default, this uses
        the identity of the named object in the user namespace to remove
        references held under other names. The object is also removed
        from the output history.

        Options
          -n : Delete the specified name from all namespaces, without
          checking their identity.
        """
        opts, varname = self.parse_options(parameter_s,'n')
        try:
            self.shell.del_var(varname, ('n' in opts))
        except (NameError, ValueError) as e:
            print type(e).__name__ +": "+ str(e)


@register_magics
class ExecutionMagics(Magics):
    """Magics related to code execution, debugging, profiling, etc.

    """

    def __init__(self, shell):
        super(ExecutionMagics, self).__init__(shell)
        if profile is None:
            self.prun = self.profile_missing_notice
        # Default execution function used to actually run user code.
        self.default_runner = None

    def profile_missing_notice(self, *args, **kwargs):
        error("""\
The profile module could not be found. It has been removed from the standard
python packages because of its non-free license. To use profiling, install the
python-profiler package from non-free.""")

    @skip_doctest
    @line_magic
    def prun(self, parameter_s='',user_mode=1,
                   opts=None,arg_lst=None,prog_ns=None):

        """Run a statement through the python code profiler.

        Usage:
          %prun [options] statement

        The given statement (which doesn't require quote marks) is run via the
        python profiler in a manner similar to the profile.run() function.
        Namespaces are internally managed to work correctly; profile.run
        cannot be used in IPython because it makes certain assumptions about
        namespaces which do not hold under IPython.

        Options:

        -l <limit>: you can place restrictions on what or how much of the
        profile gets printed. The limit value can be:

          * A string: only information for function names containing this string
          is printed.

          * An integer: only these many lines are printed.

          * A float (between 0 and 1): this fraction of the report is printed
          (for example, use a limit of 0.4 to see the topmost 40% only).

        You can combine several limits with repeated use of the option. For
        example, '-l __init__ -l 5' will print only the topmost 5 lines of
        information about class constructors.

        -r: return the pstats.Stats object generated by the profiling. This
        object has all the information about the profile in it, and you can
        later use it for further analysis or in other functions.

       -s <key>: sort profile by given key. You can provide more than one key
        by using the option several times: '-s key1 -s key2 -s key3...'. The
        default sorting key is 'time'.

        The following is copied verbatim from the profile documentation
        referenced below:

        When more than one key is provided, additional keys are used as
        secondary criteria when the there is equality in all keys selected
        before them.

        Abbreviations can be used for any key names, as long as the
        abbreviation is unambiguous.  The following are the keys currently
        defined:

                Valid Arg       Meaning
                  "calls"      call count
                  "cumulative" cumulative time
                  "file"       file name
                  "module"     file name
                  "pcalls"     primitive call count
                  "line"       line number
                  "name"       function name
                  "nfl"        name/file/line
                  "stdname"    standard name
                  "time"       internal time

        Note that all sorts on statistics are in descending order (placing
        most time consuming items first), where as name, file, and line number
        searches are in ascending order (i.e., alphabetical). The subtle
        distinction between "nfl" and "stdname" is that the standard name is a
        sort of the name as printed, which means that the embedded line
        numbers get compared in an odd way.  For example, lines 3, 20, and 40
        would (if the file names were the same) appear in the string order
        "20" "3" and "40".  In contrast, "nfl" does a numeric compare of the
        line numbers.  In fact, sort_stats("nfl") is the same as
        sort_stats("name", "file", "line").

        -T <filename>: save profile results as shown on screen to a text
        file. The profile is still shown on screen.

        -D <filename>: save (via dump_stats) profile statistics to given
        filename. This data is in a format understood by the pstats module, and
        is generated by a call to the dump_stats() method of profile
        objects. The profile is still shown on screen.

        -q: suppress output to the pager.  Best used with -T and/or -D above.

        If you want to run complete programs under the profiler's control, use
        '%run -p [prof_opts] filename.py [args to program]' where prof_opts
        contains profiler specific options as described here.

        You can read the complete documentation for the profile module with::

          In [1]: import profile; profile.help()
        """

        opts_def = Struct(D=[''],l=[],s=['time'],T=[''])

        if user_mode:  # regular user call
            opts,arg_str = self.parse_options(parameter_s,'D:l:rs:T:q',
                                              list_all=1, posix=False)
            namespace = self.shell.user_ns
        else:  # called to run a program by %run -p
            try:
                filename = get_py_filename(arg_lst[0])
            except IOError as e:
                try:
                    msg = str(e)
                except UnicodeError:
                    msg = e.message
                error(msg)
                return

            arg_str = 'execfile(filename,prog_ns)'
            namespace = {
                'execfile': self.shell.safe_execfile,
                'prog_ns': prog_ns,
                'filename': filename
                }

        opts.merge(opts_def)

        prof = profile.Profile()
        try:
            prof = prof.runctx(arg_str,namespace,namespace)
            sys_exit = ''
        except SystemExit:
            sys_exit = """*** SystemExit exception caught in code being profiled."""

        stats = pstats.Stats(prof).strip_dirs().sort_stats(*opts.s)

        lims = opts.l
        if lims:
            lims = []  # rebuild lims with ints/floats/strings
            for lim in opts.l:
                try:
                    lims.append(int(lim))
                except ValueError:
                    try:
                        lims.append(float(lim))
                    except ValueError:
                        lims.append(lim)

        # Trap output.
        stdout_trap = StringIO()

        if hasattr(stats,'stream'):
            # In newer versions of python, the stats object has a 'stream'
            # attribute to write into.
            stats.stream = stdout_trap
            stats.print_stats(*lims)
        else:
            # For older versions, we manually redirect stdout during printing
            sys_stdout = sys.stdout
            try:
                sys.stdout = stdout_trap
                stats.print_stats(*lims)
            finally:
                sys.stdout = sys_stdout

        output = stdout_trap.getvalue()
        output = output.rstrip()

        if 'q' not in opts:
            page.page(output)
        print sys_exit,

        dump_file = opts.D[0]
        text_file = opts.T[0]
        if dump_file:
            dump_file = unquote_filename(dump_file)
            prof.dump_stats(dump_file)
            print '\n*** Profile stats marshalled to file',\
                  `dump_file`+'.',sys_exit
        if text_file:
            text_file = unquote_filename(text_file)
            pfile = open(text_file,'w')
            pfile.write(output)
            pfile.close()
            print '\n*** Profile printout saved to text file',\
                  `text_file`+'.',sys_exit

        if opts.has_key('r'):
            return stats
        else:
            return None

    @line_magic
    def pdb(self, parameter_s=''):
        """Control the automatic calling of the pdb interactive debugger.

        Call as '%pdb on', '%pdb 1', '%pdb off' or '%pdb 0'. If called without
        argument it works as a toggle.

        When an exception is triggered, IPython can optionally call the
        interactive pdb debugger after the traceback printout. %pdb toggles
        this feature on and off.

        The initial state of this feature is set in your configuration
        file (the option is ``InteractiveShell.pdb``).

        If you want to just activate the debugger AFTER an exception has fired,
        without having to type '%pdb on' and rerunning your code, you can use
        the %debug magic."""

        par = parameter_s.strip().lower()

        if par:
            try:
                new_pdb = {'off':0,'0':0,'on':1,'1':1}[par]
            except KeyError:
                print ('Incorrect argument. Use on/1, off/0, '
                       'or nothing for a toggle.')
                return
        else:
            # toggle
            new_pdb = not self.shell.call_pdb

        # set on the shell
        self.shell.call_pdb = new_pdb
        print 'Automatic pdb calling has been turned',on_off(new_pdb)

    @line_magic
    def debug(self, parameter_s=''):
        """Activate the interactive debugger in post-mortem mode.

        If an exception has just occurred, this lets you inspect its stack
        frames interactively.  Note that this will always work only on the last
        traceback that occurred, so you must call this quickly after an
        exception that you wish to inspect has fired, because if another one
        occurs, it clobbers the previous one.

        If you want IPython to automatically do this on every exception, see
        the %pdb magic for more details.
        """
        self.shell.debugger(force=True)

    @line_magic
    def tb(self, s):
        """Print the last traceback with the currently active exception mode.

        See %xmode for changing exception reporting modes."""
        self.shell.showtraceback()

    @skip_doctest
    @line_magic
    def run(self, parameter_s='', runner=None,
                  file_finder=get_py_filename):
        """Run the named file inside IPython as a program.

        Usage:\\
          %run [-n -i -t [-N<N>] -d [-b<N>] -p [profile options]] file [args]

        Parameters after the filename are passed as command-line arguments to
        the program (put in sys.argv). Then, control returns to IPython's
        prompt.

        This is similar to running at a system prompt:\\
          $ python file args\\
        but with the advantage of giving you IPython's tracebacks, and of
        loading all variables into your interactive namespace for further use
        (unless -p is used, see below).

        The file is executed in a namespace initially consisting only of
        __name__=='__main__' and sys.argv constructed as indicated. It thus
        sees its environment as if it were being run as a stand-alone program
        (except for sharing global objects such as previously imported
        modules). But after execution, the IPython interactive namespace gets
        updated with all variables defined in the program (except for __name__
        and sys.argv). This allows for very convenient loading of code for
        interactive work, while giving each program a 'clean sheet' to run in.

        Options:

        -n: __name__ is NOT set to '__main__', but to the running file's name
        without extension (as python does under import).  This allows running
        scripts and reloading the definitions in them without calling code
        protected by an ' if __name__ == "__main__" ' clause.

        -i: run the file in IPython's namespace instead of an empty one. This
        is useful if you are experimenting with code written in a text editor
        which depends on variables defined interactively.

        -e: ignore sys.exit() calls or SystemExit exceptions in the script
        being run.  This is particularly useful if IPython is being used to
        run unittests, which always exit with a sys.exit() call.  In such
        cases you are interested in the output of the test results, not in
        seeing a traceback of the unittest module.

        -t: print timing information at the end of the run.  IPython will give
        you an estimated CPU time consumption for your script, which under
        Unix uses the resource module to avoid the wraparound problems of
        time.clock().  Under Unix, an estimate of time spent on system tasks
        is also given (for Windows platforms this is reported as 0.0).

        If -t is given, an additional -N<N> option can be given, where <N>
        must be an integer indicating how many times you want the script to
        run.  The final timing report will include total and per run results.

        For example (testing the script uniq_stable.py)::

            In [1]: run -t uniq_stable

            IPython CPU timings (estimated):\\
              User  :    0.19597 s.\\
              System:        0.0 s.\\

            In [2]: run -t -N5 uniq_stable

            IPython CPU timings (estimated):\\
            Total runs performed: 5\\
              Times :      Total       Per run\\
              User  :   0.910862 s,  0.1821724 s.\\
              System:        0.0 s,        0.0 s.

        -d: run your program under the control of pdb, the Python debugger.
        This allows you to execute your program step by step, watch variables,
        etc.  Internally, what IPython does is similar to calling:

          pdb.run('execfile("YOURFILENAME")')

        with a breakpoint set on line 1 of your file.  You can change the line
        number for this automatic breakpoint to be <N> by using the -bN option
        (where N must be an integer).  For example::

          %run -d -b40 myscript

        will set the first breakpoint at line 40 in myscript.py.  Note that
        the first breakpoint must be set on a line which actually does
        something (not a comment or docstring) for it to stop execution.

        When the pdb debugger starts, you will see a (Pdb) prompt.  You must
        first enter 'c' (without quotes) to start execution up to the first
        breakpoint.

        Entering 'help' gives information about the use of the debugger.  You
        can easily see pdb's full documentation with "import pdb;pdb.help()"
        at a prompt.

        -p: run program under the control of the Python profiler module (which
        prints a detailed report of execution times, function calls, etc).

        You can pass other options after -p which affect the behavior of the
        profiler itself. See the docs for %prun for details.

        In this mode, the program's variables do NOT propagate back to the
        IPython interactive namespace (because they remain in the namespace
        where the profiler executes them).

        Internally this triggers a call to %prun, see its documentation for
        details on the options available specifically for profiling.

        There is one special usage for which the text above doesn't apply:
        if the filename ends with .ipy, the file is run as ipython script,
        just as if the commands were written on IPython prompt.

        -m: specify module name to load instead of script path. Similar to
        the -m option for the python interpreter. Use this option last if you
        want to combine with other %run options. Unlike the python interpreter
        only source modules are allowed no .pyc or .pyo files.
        For example::

            %run -m example

        will run the example module.

        """

        # get arguments and set sys.argv for program to be run.
        opts, arg_lst = self.parse_options(parameter_s, 'nidtN:b:pD:l:rs:T:em:',
                                           mode='list', list_all=1)
        if "m" in opts:
            modulename = opts["m"][0]
            modpath = find_mod(modulename)
            if modpath is None:
                warn('%r is not a valid modulename on sys.path'%modulename)
                return
            arg_lst = [modpath] + arg_lst
        try:
            filename = file_finder(arg_lst[0])
        except IndexError:
            warn('you must provide at least a filename.')
            print '\n%run:\n', oinspect.getdoc(self.magic_run)
            return
        except IOError as e:
            try:
                msg = str(e)
            except UnicodeError:
                msg = e.message
            error(msg)
            return

        if filename.lower().endswith('.ipy'):
            self.shell.safe_execfile_ipy(filename)
            return

        # Control the response to exit() calls made by the script being run
        exit_ignore = 'e' in opts

        # Make sure that the running script gets a proper sys.argv as if it
        # were run from a system shell.
        save_argv = sys.argv # save it for later restoring

        # simulate shell expansion on arguments, at least tilde expansion
        args = [ os.path.expanduser(a) for a in arg_lst[1:] ]

        sys.argv = [filename] + args  # put in the proper filename
        # protect sys.argv from potential unicode strings on Python 2:
        if not py3compat.PY3:
            sys.argv = [ py3compat.cast_bytes(a) for a in sys.argv ]

        if 'i' in opts:
            # Run in user's interactive namespace
            prog_ns = self.shell.user_ns
            __name__save = self.shell.user_ns['__name__']
            prog_ns['__name__'] = '__main__'
            main_mod = self.shell.new_main_mod(prog_ns)
        else:
            # Run in a fresh, empty namespace
            if 'n' in opts:
                name = os.path.splitext(os.path.basename(filename))[0]
            else:
                name = '__main__'

            main_mod = self.shell.new_main_mod()
            prog_ns = main_mod.__dict__
            prog_ns['__name__'] = name

        # Since '%run foo' emulates 'python foo.py' at the cmd line, we must
        # set the __file__ global in the script's namespace
        prog_ns['__file__'] = filename

        # pickle fix.  See interactiveshell for an explanation.  But we need to make sure
        # that, if we overwrite __main__, we replace it at the end
        main_mod_name = prog_ns['__name__']

        if main_mod_name == '__main__':
            restore_main = sys.modules['__main__']
        else:
            restore_main = False

        # This needs to be undone at the end to prevent holding references to
        # every single object ever created.
        sys.modules[main_mod_name] = main_mod

        try:
            stats = None
            with self.shell.readline_no_record:
                if 'p' in opts:
                    stats = self.prun('', 0, opts, arg_lst, prog_ns)
                else:
                    if 'd' in opts:
                        deb = debugger.Pdb(self.shell.colors)
                        # reset Breakpoint state, which is moronically kept
                        # in a class
                        bdb.Breakpoint.next = 1
                        bdb.Breakpoint.bplist = {}
                        bdb.Breakpoint.bpbynumber = [None]
                        # Set an initial breakpoint to stop execution
                        maxtries = 10
                        bp = int(opts.get('b', [1])[0])
                        checkline = deb.checkline(filename, bp)
                        if not checkline:
                            for bp in range(bp + 1, bp + maxtries + 1):
                                if deb.checkline(filename, bp):
                                    break
                            else:
                                msg = ("\nI failed to find a valid line to set "
                                       "a breakpoint\n"
                                       "after trying up to line: %s.\n"
                                       "Please set a valid breakpoint manually "
                                       "with the -b option." % bp)
                                error(msg)
                                return
                        # if we find a good linenumber, set the breakpoint
                        deb.do_break('%s:%s' % (filename, bp))
                        # Start file run
                        print "NOTE: Enter 'c' at the",
                        print "%s prompt to start your script." % deb.prompt
                        ns = {'execfile': py3compat.execfile, 'prog_ns': prog_ns}
                        try:
                            deb.run('execfile("%s", prog_ns)' % filename, ns)

                        except:
                            etype, value, tb = sys.exc_info()
                            # Skip three frames in the traceback: the %run one,
                            # one inside bdb.py, and the command-line typed by the
                            # user (run by exec in pdb itself).
                            self.shell.InteractiveTB(etype, value, tb, tb_offset=3)
                    else:
                        if runner is None:
                            runner = self.default_runner
                        if runner is None:
                            runner = self.shell.safe_execfile
                        if 't' in opts:
                            # timed execution
                            try:
                                nruns = int(opts['N'][0])
                                if nruns < 1:
                                    error('Number of runs must be >=1')
                                    return
                            except (KeyError):
                                nruns = 1
                            twall0 = time.time()
                            if nruns == 1:
                                t0 = clock2()
                                runner(filename, prog_ns, prog_ns,
                                       exit_ignore=exit_ignore)
                                t1 = clock2()
                                t_usr = t1[0] - t0[0]
                                t_sys = t1[1] - t0[1]
                                print "\nIPython CPU timings (estimated):"
                                print "  User   : %10.2f s." % t_usr
                                print "  System : %10.2f s." % t_sys
                            else:
                                runs = range(nruns)
                                t0 = clock2()
                                for nr in runs:
                                    runner(filename, prog_ns, prog_ns,
                                           exit_ignore=exit_ignore)
                                t1 = clock2()
                                t_usr = t1[0] - t0[0]
                                t_sys = t1[1] - t0[1]
                                print "\nIPython CPU timings (estimated):"
                                print "Total runs performed:", nruns
                                print "  Times  : %10.2f    %10.2f" % ('Total', 'Per run')
                                print "  User   : %10.2f s, %10.2f s." % (t_usr, t_usr / nruns)
                                print "  System : %10.2f s, %10.2f s." % (t_sys, t_sys / nruns)
                            twall1 = time.time()
                            print "Wall time: %10.2f s." % (twall1 - twall0)

                        else:
                            # regular execution
                            runner(filename, prog_ns, prog_ns, exit_ignore=exit_ignore)

                if 'i' in opts:
                    self.shell.user_ns['__name__'] = __name__save
                else:
                    # The shell MUST hold a reference to prog_ns so after %run
                    # exits, the python deletion mechanism doesn't zero it out
                    # (leaving dangling references).
                    self.shell.cache_main_mod(prog_ns, filename)
                    # update IPython interactive namespace

                    # Some forms of read errors on the file may mean the
                    # __name__ key was never set; using pop we don't have to
                    # worry about a possible KeyError.
                    prog_ns.pop('__name__', None)

                    self.shell.user_ns.update(prog_ns)
        finally:
            # It's a bit of a mystery why, but __builtins__ can change from
            # being a module to becoming a dict missing some key data after
            # %run.  As best I can see, this is NOT something IPython is doing
            # at all, and similar problems have been reported before:
            # http://coding.derkeiler.com/Archive/Python/comp.lang.python/2004-10/0188.html
            # Since this seems to be done by the interpreter itself, the best
            # we can do is to at least restore __builtins__ for the user on
            # exit.
            self.shell.user_ns['__builtins__'] = builtin_mod

            # Ensure key global structures are restored
            sys.argv = save_argv
            if restore_main:
                sys.modules['__main__'] = restore_main
            else:
                # Remove from sys.modules the reference to main_mod we'd
                # added.  Otherwise it will trap references to objects
                # contained therein.
                del sys.modules[main_mod_name]

        return stats

    @skip_doctest
    @line_magic
    def timeit(self, parameter_s=''):
        """Time execution of a Python statement or expression

        Usage:\\
          %timeit [-n<N> -r<R> [-t|-c]] statement

        Time execution of a Python statement or expression using the timeit
        module.

        Options:
        -n<N>: execute the given statement <N> times in a loop. If this value
        is not given, a fitting value is chosen.

        -r<R>: repeat the loop iteration <R> times and take the best result.
        Default: 3

        -t: use time.time to measure the time, which is the default on Unix.
        This function measures wall time.

        -c: use time.clock to measure the time, which is the default on
        Windows and measures wall time. On Unix, resource.getrusage is used
        instead and returns the CPU user time.

        -p<P>: use a precision of <P> digits to display the timing result.
        Default: 3


        Examples
        --------
        ::

          In [1]: %timeit pass
          10000000 loops, best of 3: 53.3 ns per loop

          In [2]: u = None

          In [3]: %timeit u is None
          10000000 loops, best of 3: 184 ns per loop

          In [4]: %timeit -r 4 u == None
          1000000 loops, best of 4: 242 ns per loop

          In [5]: import time

          In [6]: %timeit -n1 time.sleep(2)
          1 loops, best of 3: 2 s per loop


        The times reported by %timeit will be slightly higher than those
        reported by the timeit.py script when variables are accessed. This is
        due to the fact that %timeit executes the statement in the namespace
        of the shell, compared with timeit.py, which uses a single setup
        statement to import function or create variables. Generally, the bias
        does not matter as long as results from timeit.py are not mixed with
        those from %timeit."""

        import timeit
        import math

        # XXX: Unfortunately the unicode 'micro' symbol can cause problems in
        # certain terminals.  Until we figure out a robust way of
        # auto-detecting if the terminal can deal with it, use plain 'us' for
        # microseconds.  I am really NOT happy about disabling the proper
        # 'micro' prefix, but crashing is worse... If anyone knows what the
        # right solution for this is, I'm all ears...
        #
        # Note: using
        #
        # s = u'\xb5'
        # s.encode(sys.getdefaultencoding())
        #
        # is not sufficient, as I've seen terminals where that fails but
        # print s
        #
        # succeeds
        #
        # See bug: https://bugs.launchpad.net/ipython/+bug/348466

        #units = [u"s", u"ms",u'\xb5',"ns"]
        units = [u"s", u"ms",u'us',"ns"]

        scaling = [1, 1e3, 1e6, 1e9]

        opts, stmt = self.parse_options(parameter_s,'n:r:tcp:',
                                        posix=False, strict=False)
        if stmt == "":
            return
        timefunc = timeit.default_timer
        number = int(getattr(opts, "n", 0))
        repeat = int(getattr(opts, "r", timeit.default_repeat))
        precision = int(getattr(opts, "p", 3))
        if hasattr(opts, "t"):
            timefunc = time.time
        if hasattr(opts, "c"):
            timefunc = clock

        timer = timeit.Timer(timer=timefunc)
        # this code has tight coupling to the inner workings of timeit.Timer,
        # but is there a better way to achieve that the code stmt has access
        # to the shell namespace?

        src = timeit.template % {'stmt': timeit.reindent(stmt, 8),
                                 'setup': "pass"}
        # Track compilation time so it can be reported if too long
        # Minimum time above which compilation time will be reported
        tc_min = 0.1

        t0 = clock()
        code = compile(src, "<magic-timeit>", "exec")
        tc = clock()-t0

        ns = {}
        exec code in self.shell.user_ns, ns
        timer.inner = ns["inner"]

        if number == 0:
            # determine number so that 0.2 <= total time < 2.0
            number = 1
            for i in range(1, 10):
                if timer.timeit(number) >= 0.2:
                    break
                number *= 10

        best = min(timer.repeat(repeat, number)) / number

        if best > 0.0 and best < 1000.0:
            order = min(-int(math.floor(math.log10(best)) // 3), 3)
        elif best >= 1000.0:
            order = 0
        else:
            order = 3
        print u"%d loops, best of %d: %.*g %s per loop" % (number, repeat,
                                                          precision,
                                                          best * scaling[order],
                                                          units[order])
        if tc > tc_min:
            print "Compiler time: %.2f s" % tc

    @cell_magic('timeit')
    def cell_timeit(self, line, cell):
        """Time execution of a Python cell."""
        raise NotImplementedError

    @skip_doctest
    @needs_local_scope
    @line_magic
    def time(self,parameter_s, user_locals):
        """Time execution of a Python statement or expression.

        The CPU and wall clock times are printed, and the value of the
        expression (if any) is returned.  Note that under Win32, system time
        is always reported as 0, since it can not be measured.

        This function provides very basic timing functionality.  In Python
        2.3, the timeit module offers more control and sophistication, so this
        could be rewritten to use it (patches welcome).

        Examples
        --------
        ::

          In [1]: time 2**128
          CPU times: user 0.00 s, sys: 0.00 s, total: 0.00 s
          Wall time: 0.00
          Out[1]: 340282366920938463463374607431768211456L

          In [2]: n = 1000000

          In [3]: time sum(range(n))
          CPU times: user 1.20 s, sys: 0.05 s, total: 1.25 s
          Wall time: 1.37
          Out[3]: 499999500000L

          In [4]: time print 'hello world'
          hello world
          CPU times: user 0.00 s, sys: 0.00 s, total: 0.00 s
          Wall time: 0.00

          Note that the time needed by Python to compile the given expression
          will be reported if it is more than 0.1s.  In this example, the
          actual exponentiation is done by Python at compilation time, so while
          the expression can take a noticeable amount of time to compute, that
          time is purely due to the compilation:

          In [5]: time 3**9999;
          CPU times: user 0.00 s, sys: 0.00 s, total: 0.00 s
          Wall time: 0.00 s

          In [6]: time 3**999999;
          CPU times: user 0.00 s, sys: 0.00 s, total: 0.00 s
          Wall time: 0.00 s
          Compiler : 0.78 s
          """

        # fail immediately if the given expression can't be compiled

        expr = self.shell.prefilter(parameter_s,False)

        # Minimum time above which compilation time will be reported
        tc_min = 0.1

        try:
            mode = 'eval'
            t0 = clock()
            code = compile(expr,'<timed eval>',mode)
            tc = clock()-t0
        except SyntaxError:
            mode = 'exec'
            t0 = clock()
            code = compile(expr,'<timed exec>',mode)
            tc = clock()-t0
        # skew measurement as little as possible
        glob = self.shell.user_ns
        wtime = time.time
        # time execution
        wall_st = wtime()
        if mode=='eval':
            st = clock2()
            out = eval(code, glob, user_locals)
            end = clock2()
        else:
            st = clock2()
            exec code in glob, user_locals
            end = clock2()
            out = None
        wall_end = wtime()
        # Compute actual times and report
        wall_time = wall_end-wall_st
        cpu_user = end[0]-st[0]
        cpu_sys = end[1]-st[1]
        cpu_tot = cpu_user+cpu_sys
        print "CPU times: user %.2f s, sys: %.2f s, total: %.2f s" % \
              (cpu_user,cpu_sys,cpu_tot)
        print "Wall time: %.2f s" % wall_time
        if tc > tc_min:
            print "Compiler : %.2f s" % tc
        return out

    @skip_doctest
    @line_magic
    def macro(self, parameter_s=''):
        """Define a macro for future re-execution. It accepts ranges of history,
        filenames or string objects.

        Usage:\\
          %macro [options] name 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 will define a global variable called `name` which is a string
        made of joining the slices and lines you specify (n1,n2,... numbers
        above) from your input history into a single string. This variable
        acts like an automatic function which re-executes those lines as if
        you had typed them. You just type 'name' at the prompt and the code
        executes.

        The syntax for indicating input ranges is described in %history.

        Note: as a 'hidden' feature, you can also use traditional python slice
        notation, where N:M means numbers N through M-1.

        For example, if your history contains (%hist prints it)::

          44: x=1
          45: y=3
          46: z=x+y
          47: print x
          48: a=5
          49: print 'x',x,'y',y

        you can create a macro with lines 44 through 47 (included) and line 49
        called my_macro with::

          In [55]: %macro my_macro 44-47 49

        Now, typing `my_macro` (without quotes) will re-execute all this code
        in one pass.

        You don't need to give the line-numbers in order, and any given line
        number can appear multiple times. You can assemble macros with any
        lines from your input history in any order.

        The macro is a simple object which holds its value in an attribute,
        but IPython's display system checks for macros and executes them as
        code instead of printing them when you type their name.

        You can view a macro's contents by explicitly printing it with::

          print macro_name

        """
        opts,args = self.parse_options(parameter_s,'r',mode='list')
        if not args:   # List existing macros
            return sorted(k for k,v in self.shell.user_ns.iteritems() if\
                                                        isinstance(v, Macro))
        if len(args) == 1:
            raise UsageError(
                "%macro insufficient args; usage '%macro name n1-n2 n3-4...")
        name, codefrom = args[0], " ".join(args[1:])

        #print 'rng',ranges  # dbg
        try:
            lines = self.shell.find_user_code(codefrom, 'r' in opts)
        except (ValueError, TypeError) as e:
            print e.args[0]
            return
        macro = Macro(lines)
        self.shell.define_macro(name, macro)
        print 'Macro `%s` created. To execute, type its name (without quotes).' % name
        print '=== Macro contents: ==='
        print macro,


@register_magics
class AutoMagics(Magics):
    """Magics that control various autoX behaviors."""

    def __init__(self, shell):
        super(AutoMagics, self).__init__(shell)
        # namespace for holding state we may need
        self._magic_state = Bunch()

    @line_magic
    def automagic(self, parameter_s=''):
        """Make magic functions callable without having to type the initial %.

        Without argumentsl toggles on/off (when off, you must call it as
        %automagic, of course).  With arguments it sets the value, and you can
        use any of (case insensitive):

         - on, 1, True: to activate

         - off, 0, False: to deactivate.

        Note that magic functions have lowest priority, so if there's a
        variable whose name collides with that of a magic fn, automagic won't
        work for that function (you get the variable instead). However, if you
        delete the variable (del var), the previously shadowed magic function
        becomes visible to automagic again."""

        arg = parameter_s.lower()
        mman = self.shell.magics_manager
        if arg in ('on', '1', 'true'):
            val = True
        elif arg in ('off', '0', 'false'):
            val = False
        else:
            val = not mman.auto_magic
        mman.auto_magic = val
        print '\n' + self.shell.magics_manager.auto_status()

    @skip_doctest
    @line_magic
    def autocall(self, parameter_s=''):
        """Make functions callable without having to type parentheses.

        Usage:

           %autocall [mode]

        The mode can be one of: 0->Off, 1->Smart, 2->Full.  If not given, the
        value is toggled on and off (remembering the previous state).

        In more detail, these values mean:

        0 -> fully disabled

        1 -> active, but do not apply if there are no arguments on the line.

        In this mode, you get::

          In [1]: callable
          Out[1]: <built-in function callable>

          In [2]: callable 'hello'
          ------> callable('hello')
          Out[2]: False

        2 -> Active always.  Even if no arguments are present, the callable
        object is called::

          In [2]: float
          ------> float()
          Out[2]: 0.0

        Note that even with autocall off, you can still use '/' at the start of
        a line to treat the first argument on the command line as a function
        and add parentheses to it::

          In [8]: /str 43
          ------> str(43)
          Out[8]: '43'

        # all-random (note for auto-testing)
        """

        if parameter_s:
            arg = int(parameter_s)
        else:
            arg = 'toggle'

        if not arg in (0, 1, 2,'toggle'):
            error('Valid modes: (0->Off, 1->Smart, 2->Full')
            return

        if arg in (0, 1, 2):
            self.shell.autocall = arg
        else: # toggle
            if self.shell.autocall:
                self._magic_state.autocall_save = self.shell.autocall
                self.shell.autocall = 0
            else:
                try:
                    self.shell.autocall = self._magic_state.autocall_save
                except AttributeError:
                    self.shell.autocall = self._magic_state.autocall_save = 1

        print "Automatic calling is:",['OFF','Smart','Full'][self.shell.autocall]


@register_magics
class OSMagics(Magics):
    """Magics to interact with the underlying OS (shell-type functionality).
    """

    @skip_doctest
    @line_magic
    def alias(self, parameter_s=''):
        """Define an alias for a system command.

        '%alias alias_name cmd' defines 'alias_name' as an alias for 'cmd'

        Then, typing 'alias_name params' will execute the system command 'cmd
        params' (from your underlying operating system).

        Aliases have lower precedence than magic functions and Python normal
        variables, so if 'foo' is both a Python variable and an alias, the
        alias can not be executed until 'del foo' removes the Python variable.

        You can use the %l specifier in an alias definition to represent the
        whole line when the alias is called.  For example::

          In [2]: alias bracket echo "Input in brackets: <%l>"
          In [3]: bracket hello world
          Input in brackets: <hello world>

        You can also define aliases with parameters using %s specifiers (one
        per parameter)::

          In [1]: alias parts echo first %s second %s
          In [2]: %parts A B
          first A second B
          In [3]: %parts A
          Incorrect number of arguments: 2 expected.
          parts is an alias to: 'echo first %s second %s'

        Note that %l and %s are mutually exclusive.  You can only use one or
        the other in your aliases.

        Aliases expand Python variables just like system calls using ! or !!
        do: all expressions prefixed with '$' get expanded.  For details of
        the semantic rules, see PEP-215:
        http://www.python.org/peps/pep-0215.html.  This is the library used by
        IPython for variable expansion.  If you want to access a true shell
        variable, an extra $ is necessary to prevent its expansion by
        IPython::

          In [6]: alias show echo
          In [7]: PATH='A Python string'
          In [8]: show $PATH
          A Python string
          In [9]: show $$PATH
          /usr/local/lf9560/bin:/usr/local/intel/compiler70/ia32/bin:...

        You can use the alias facility to acess all of $PATH.  See the %rehash
        and %rehashx functions, which automatically create aliases for the
        contents of your $PATH.

        If called with no parameters, %alias prints the current alias table."""

        par = parameter_s.strip()
        if not par:
            aliases = sorted(self.shell.alias_manager.aliases)
            # stored = self.shell.db.get('stored_aliases', {} )
            # for k, v in stored:
            #     atab.append(k, v[0])

            print "Total number of aliases:", len(aliases)
            sys.stdout.flush()
            return aliases

        # Now try to define a new one
        try:
            alias,cmd = par.split(None, 1)
        except:
            print oinspect.getdoc(self.magic_alias)
        else:
            self.shell.alias_manager.soft_define_alias(alias, cmd)
    # end magic_alias

    @line_magic
    def unalias(self, parameter_s=''):
        """Remove an alias"""

        aname = parameter_s.strip()
        self.shell.alias_manager.undefine_alias(aname)
        stored = self.shell.db.get('stored_aliases', {} )
        if aname in stored:
            print "Removing %stored alias",aname
            del stored[aname]
            self.shell.db['stored_aliases'] = stored

    @line_magic
    def rehashx(self, parameter_s=''):
        """Update the alias table with all executable files in $PATH.

        This version explicitly checks that every entry in $PATH is a file
        with execute access (os.X_OK), so it is much slower than %rehash.

        Under Windows, it checks executability as a match against a
        '|'-separated string of extensions, stored in the IPython config
        variable win_exec_ext.  This defaults to 'exe|com|bat'.

        This function also resets the root module cache of module completer,
        used on slow filesystems.
        """
        from IPython.core.alias import InvalidAliasError

        # for the benefit of module completer in ipy_completers.py
        del self.shell.db['rootmodules']

        path = [os.path.abspath(os.path.expanduser(p)) for p in
            os.environ.get('PATH','').split(os.pathsep)]
        path = filter(os.path.isdir,path)

        syscmdlist = []
        # Now define isexec in a cross platform manner.
        if os.name == 'posix':
            isexec = lambda fname:os.path.isfile(fname) and \
                     os.access(fname,os.X_OK)
        else:
            try:
                winext = os.environ['pathext'].replace(';','|').replace('.','')
            except KeyError:
                winext = 'exe|com|bat|py'
            if 'py' not in winext:
                winext += '|py'
            execre = re.compile(r'(.*)\.(%s)$' % winext,re.IGNORECASE)
            isexec = lambda fname:os.path.isfile(fname) and execre.match(fname)
        savedir = os.getcwdu()

        # Now walk the paths looking for executables to alias.
        try:
            # write the whole loop for posix/Windows so we don't have an if in
            # the innermost part
            if os.name == 'posix':
                for pdir in path:
                    os.chdir(pdir)
                    for ff in os.listdir(pdir):
                        if isexec(ff):
                            try:
                                # Removes dots from the name since ipython
                                # will assume names with dots to be python.
                                self.shell.alias_manager.define_alias(
                                    ff.replace('.',''), ff)
                            except InvalidAliasError:
                                pass
                            else:
                                syscmdlist.append(ff)
            else:
                no_alias = self.shell.alias_manager.no_alias
                for pdir in path:
                    os.chdir(pdir)
                    for ff in os.listdir(pdir):
                        base, ext = os.path.splitext(ff)
                        if isexec(ff) and base.lower() not in no_alias:
                            if ext.lower() == '.exe':
                                ff = base
                                try:
                                    # Removes dots from the name since ipython
                                    # will assume names with dots to be python.
                                    self.shell.alias_manager.define_alias(
                                        base.lower().replace('.',''), ff)
                                except InvalidAliasError:
                                    pass
                                syscmdlist.append(ff)
            self.shell.db['syscmdlist'] = syscmdlist
        finally:
            os.chdir(savedir)

    @skip_doctest
    @line_magic
    def pwd(self, parameter_s=''):
        """Return the current working directory path.

        Examples
        --------
        ::

          In [9]: pwd
          Out[9]: '/home/tsuser/sprint/ipython'
        """
        return os.getcwdu()

    @skip_doctest
    @line_magic
    def cd(self, parameter_s=''):
        """Change the current working directory.

        This command automatically maintains an internal list of directories
        you visit during your IPython session, in the variable _dh. The
        command %dhist shows this history nicely formatted. You can also
        do 'cd -<tab>' to see directory history conveniently.

        Usage:

          cd 'dir': changes to directory 'dir'.

          cd -: changes to the last visited directory.

          cd -<n>: changes to the n-th directory in the directory history.

          cd --foo: change to directory that matches 'foo' in history

          cd -b <bookmark_name>: jump to a bookmark set by %bookmark
             (note: cd <bookmark_name> is enough if there is no
              directory <bookmark_name>, but a bookmark with the name exists.)
              'cd -b <tab>' allows you to tab-complete bookmark names.

        Options:

        -q: quiet.  Do not print the working directory after the cd command is
        executed.  By default IPython's cd command does print this directory,
        since the default prompts do not display path information.

        Note that !cd doesn't work for this purpose because the shell where
        !command runs is immediately discarded after executing 'command'.

        Examples
        --------
        ::

          In [10]: cd parent/child
          /home/tsuser/parent/child
        """

        #bkms = self.shell.persist.get("bookmarks",{})

        oldcwd = os.getcwdu()
        numcd = re.match(r'(-)(\d+)$',parameter_s)
        # jump in directory history by number
        if numcd:
            nn = int(numcd.group(2))
            try:
                ps = self.shell.user_ns['_dh'][nn]
            except IndexError:
                print 'The requested directory does not exist in history.'
                return
            else:
                opts = {}
        elif parameter_s.startswith('--'):
            ps = None
            fallback = None
            pat = parameter_s[2:]
            dh = self.shell.user_ns['_dh']
            # first search only by basename (last component)
            for ent in reversed(dh):
                if pat in os.path.basename(ent) and os.path.isdir(ent):
                    ps = ent
                    break

                if fallback is None and pat in ent and os.path.isdir(ent):
                    fallback = ent

            # if we have no last part match, pick the first full path match
            if ps is None:
                ps = fallback

            if ps is None:
                print "No matching entry in directory history"
                return
            else:
                opts = {}


        else:
            #turn all non-space-escaping backslashes to slashes,
            # for c:\windows\directory\names\
            parameter_s = re.sub(r'\\(?! )','/', parameter_s)
            opts,ps = self.parse_options(parameter_s,'qb',mode='string')
        # jump to previous
        if ps == '-':
            try:
                ps = self.shell.user_ns['_dh'][-2]
            except IndexError:
                raise UsageError('%cd -: No previous directory to change to.')
        # jump to bookmark if needed
        else:
            if not os.path.isdir(ps) or opts.has_key('b'):
                bkms = self.shell.db.get('bookmarks', {})

                if bkms.has_key(ps):
                    target = bkms[ps]
                    print '(bookmark:%s) -> %s' % (ps,target)
                    ps = target
                else:
                    if opts.has_key('b'):
                        raise UsageError("Bookmark '%s' not found.  "
                              "Use '%%bookmark -l' to see your bookmarks." % ps)

        # strip extra quotes on Windows, because os.chdir doesn't like them
        ps = unquote_filename(ps)
        # at this point ps should point to the target dir
        if ps:
            try:
                os.chdir(os.path.expanduser(ps))
                if hasattr(self.shell, 'term_title') and self.shell.term_title:
                    set_term_title('IPython: ' + abbrev_cwd())
            except OSError:
                print sys.exc_info()[1]
            else:
                cwd = os.getcwdu()
                dhist = self.shell.user_ns['_dh']
                if oldcwd != cwd:
                    dhist.append(cwd)
                    self.shell.db['dhist'] = compress_dhist(dhist)[-100:]

        else:
            os.chdir(self.shell.home_dir)
            if hasattr(self.shell, 'term_title') and self.shell.term_title:
                set_term_title('IPython: ' + '~')
            cwd = os.getcwdu()
            dhist = self.shell.user_ns['_dh']

            if oldcwd != cwd:
                dhist.append(cwd)
                self.shell.db['dhist'] = compress_dhist(dhist)[-100:]
        if not 'q' in opts and self.shell.user_ns['_dh']:
            print self.shell.user_ns['_dh'][-1]


    @line_magic
    def env(self, parameter_s=''):
        """List environment variables."""

        return dict(os.environ)

    @line_magic
    def pushd(self, parameter_s=''):
        """Place the current dir on stack and change directory.

        Usage:\\
          %pushd ['dirname']
        """

        dir_s = self.shell.dir_stack
        tgt = os.path.expanduser(unquote_filename(parameter_s))
        cwd = os.getcwdu().replace(self.shell.home_dir,'~')
        if tgt:
            self.cd(parameter_s)
        dir_s.insert(0,cwd)
        return self.shell.magic('dirs')

    @line_magic
    def popd(self, parameter_s=''):
        """Change to directory popped off the top of the stack.
        """
        if not self.shell.dir_stack:
            raise UsageError("%popd on empty stack")
        top = self.shell.dir_stack.pop(0)
        self.cd(top)
        print "popd ->",top

    @line_magic
    def dirs(self, parameter_s=''):
        """Return the current directory stack."""

        return self.shell.dir_stack

    @line_magic
    def dhist(self, parameter_s=''):
        """Print your history of visited directories.

        %dhist       -> print full history\\
        %dhist n     -> print last n entries only\\
        %dhist n1 n2 -> print entries between n1 and n2 (n1 not included)\\

        This history is automatically maintained by the %cd command, and
        always available as the global list variable _dh. You can use %cd -<n>
        to go to directory number <n>.

        Note that most of time, you should view directory history by entering
        cd -<TAB>.

        """

        dh = self.shell.user_ns['_dh']
        if parameter_s:
            try:
                args = map(int,parameter_s.split())
            except:
                self.arg_err(self.dhist)
                return
            if len(args) == 1:
                ini,fin = max(len(dh)-(args[0]),0),len(dh)
            elif len(args) == 2:
                ini,fin = args
            else:
                self.arg_err(self.dhist)
                return
        else:
            ini,fin = 0,len(dh)
        nlprint(dh,
                header = 'Directory history (kept in _dh)',
                start=ini,stop=fin)

    @skip_doctest
    @line_magic
    def sc(self, parameter_s=''):
        """Shell capture - execute a shell command and capture its output.

        DEPRECATED. Suboptimal, retained for backwards compatibility.

        You should use the form 'var = !command' instead. Example:

         "%sc -l myfiles = ls ~" should now be written as

         "myfiles = !ls ~"

        myfiles.s, myfiles.l and myfiles.n still apply as documented
        below.

        --
        %sc [options] varname=command

        IPython will run the given command using commands.getoutput(), and
        will then update the user's interactive namespace with a variable
        called varname, containing the value of the call.  Your command can
        contain shell wildcards, pipes, etc.

        The '=' sign in the syntax is mandatory, and the variable name you
        supply must follow Python's standard conventions for valid names.

        (A special format without variable name exists for internal use)

        Options:

          -l: list output.  Split the output on newlines into a list before
          assigning it to the given variable.  By default the output is stored
          as a single string.

          -v: verbose.  Print the contents of the variable.

        In most cases you should not need to split as a list, because the
        returned value is a special type of string which can automatically
        provide its contents either as a list (split on newlines) or as a
        space-separated string.  These are convenient, respectively, either
        for sequential processing or to be passed to a shell command.

        For example::

            # Capture into variable a
            In [1]: sc a=ls *py

            # a is a string with embedded newlines
            In [2]: a
            Out[2]: 'setup.py\\nwin32_manual_post_install.py'

            # which can be seen as a list:
            In [3]: a.l
            Out[3]: ['setup.py', 'win32_manual_post_install.py']

            # or as a whitespace-separated string:
            In [4]: a.s
            Out[4]: 'setup.py win32_manual_post_install.py'

            # a.s is useful to pass as a single command line:
            In [5]: !wc -l $a.s
              146 setup.py
              130 win32_manual_post_install.py
              276 total

            # while the list form is useful to loop over:
            In [6]: for f in a.l:
              ...:      !wc -l $f
              ...:
            146 setup.py
            130 win32_manual_post_install.py

        Similarly, the lists returned by the -l option are also special, in
        the sense that you can equally invoke the .s attribute on them to
        automatically get a whitespace-separated string from their contents::

            In [7]: sc -l b=ls *py

            In [8]: b
            Out[8]: ['setup.py', 'win32_manual_post_install.py']

            In [9]: b.s
            Out[9]: 'setup.py win32_manual_post_install.py'

        In summary, both the lists and strings used for output capture have
        the following special attributes::

            .l (or .list) : value as list.
            .n (or .nlstr): value as newline-separated string.
            .s (or .spstr): value as space-separated string.
        """

        opts,args = self.parse_options(parameter_s,'lv')
        # Try to get a variable name and command to run
        try:
            # the variable name must be obtained from the parse_options
            # output, which uses shlex.split to strip options out.
            var,_ = args.split('=',1)
            var = var.strip()
            # But the command has to be extracted from the original input
            # parameter_s, not on what parse_options returns, to avoid the
            # quote stripping which shlex.split performs on it.
            _,cmd = parameter_s.split('=',1)
        except ValueError:
            var,cmd = '',''
        # If all looks ok, proceed
        split = 'l' in opts
        out = self.shell.getoutput(cmd, split=split)
        if opts.has_key('v'):
            print '%s ==\n%s' % (var,pformat(out))
        if var:
            self.shell.user_ns.update({var:out})
        else:
            return out

    @line_magic
    def sx(self, parameter_s=''):
        """Shell execute - run a shell command and capture its output.

        %sx command

        IPython will run the given command using commands.getoutput(), and
        return the result formatted as a list (split on '\\n').  Since the
        output is _returned_, it will be stored in ipython's regular output
        cache Out[N] and in the '_N' automatic variables.

        Notes:

        1) If an input line begins with '!!', then %sx is automatically
        invoked.  That is, while::

          !ls

        causes ipython to simply issue system('ls'), typing::

          !!ls

        is a shorthand equivalent to::

          %sx ls

        2) %sx differs from %sc in that %sx automatically splits into a list,
        like '%sc -l'.  The reason for this is to make it as easy as possible
        to process line-oriented shell output via further python commands.
        %sc is meant to provide much finer control, but requires more
        typing.

        3) Just like %sc -l, this is a list with special attributes:
        ::

          .l (or .list) : value as list.
          .n (or .nlstr): value as newline-separated string.
          .s (or .spstr): value as whitespace-separated string.

        This is very useful when trying to use such lists as arguments to
        system commands."""

        if parameter_s:
            return self.shell.getoutput(parameter_s)


    @line_magic
    def bookmark(self, parameter_s=''):
        """Manage IPython's bookmark system.

        %bookmark <name>       - set bookmark to current dir
        %bookmark <name> <dir> - set bookmark to <dir>
        %bookmark -l           - list all bookmarks
        %bookmark -d <name>    - remove bookmark
        %bookmark -r           - remove all bookmarks

        You can later on access a bookmarked folder with::

          %cd -b <name>

        or simply '%cd <name>' if there is no directory called <name> AND
        there is such a bookmark defined.

        Your bookmarks persist through IPython sessions, but they are
        associated with each profile."""

        opts,args = self.parse_options(parameter_s,'drl',mode='list')
        if len(args) > 2:
            raise UsageError("%bookmark: too many arguments")

        bkms = self.shell.db.get('bookmarks',{})

        if opts.has_key('d'):
            try:
                todel = args[0]
            except IndexError:
                raise UsageError(
                    "%bookmark -d: must provide a bookmark to delete")
            else:
                try:
                    del bkms[todel]
                except KeyError:
                    raise UsageError(
                        "%%bookmark -d: Can't delete bookmark '%s'" % todel)

        elif opts.has_key('r'):
            bkms = {}
        elif opts.has_key('l'):
            bks = bkms.keys()
            bks.sort()
            if bks:
                size = max(map(len,bks))
            else:
                size = 0
            fmt = '%-'+str(size)+'s -> %s'
            print 'Current bookmarks:'
            for bk in bks:
                print fmt % (bk,bkms[bk])
        else:
            if not args:
                raise UsageError("%bookmark: You must specify the bookmark name")
            elif len(args)==1:
                bkms[args[0]] = os.getcwdu()
            elif len(args)==2:
                bkms[args[0]] = args[1]
        self.shell.db['bookmarks'] = bkms

    @line_magic
    def pycat(self, parameter_s=''):
        """Show a syntax-highlighted file through a pager.

        This magic is similar to the cat utility, but it will assume the file
        to be Python source and will show it with syntax highlighting. """

        try:
            filename = get_py_filename(parameter_s)
            cont = file_read(filename)
        except IOError:
            try:
                cont = eval(parameter_s, self.shell.user_ns)
            except NameError:
                cont = None
        if cont is None:
            print "Error: no such file or variable"
            return

        page.page(self.shell.pycolorize(cont))


@register_magics
class LoggingMagics(Magics):
    """Magics related to all logging machinery."""

    @line_magic
    def logstart(self, parameter_s=''):
        """Start logging anywhere in a session.

        %logstart [-o|-r|-t] [log_name [log_mode]]

        If no name is given, it defaults to a file named 'ipython_log.py' in your
        current directory, in 'rotate' mode (see below).

        '%logstart name' saves to file 'name' in 'backup' mode.  It saves your
        history up to that point and then continues logging.

        %logstart takes a second optional parameter: logging mode. This can be one
        of (note that the modes are given unquoted):\\
          append: well, that says it.\\
          backup: rename (if exists) to name~ and start name.\\
          global: single logfile in your home dir, appended to.\\
          over  : overwrite existing log.\\
          rotate: create rotating logs name.1~, name.2~, etc.

        Options:

          -o: log also IPython's output.  In this mode, all commands which
          generate an Out[NN] prompt are recorded to the logfile, right after
          their corresponding input line.  The output lines are always
          prepended with a '#[Out]# ' marker, so that the log remains valid
          Python code.

          Since this marker is always the same, filtering only the output from
          a log is very easy, using for example a simple awk call::

            awk -F'#\\[Out\\]# ' '{if($2) {print $2}}' ipython_log.py

          -r: log 'raw' input.  Normally, IPython's logs contain the processed
          input, so that user lines are logged in their final form, converted
          into valid Python.  For example, %Exit is logged as
          _ip.magic("Exit").  If the -r flag is given, all input is logged
          exactly as typed, with no transformations applied.

          -t: put timestamps before each input line logged (these are put in
          comments)."""

        opts,par = self.parse_options(parameter_s,'ort')
        log_output = 'o' in opts
        log_raw_input = 'r' in opts
        timestamp = 't' in opts

        logger = self.shell.logger

        # if no args are given, the defaults set in the logger constructor by
        # ipython remain valid
        if par:
            try:
                logfname,logmode = par.split()
            except:
                logfname = par
                logmode = 'backup'
        else:
            logfname = logger.logfname
            logmode = logger.logmode
        # put logfname into rc struct as if it had been called on the command
        # line, so it ends up saved in the log header Save it in case we need
        # to restore it...
        old_logfile = self.shell.logfile
        if logfname:
            logfname = os.path.expanduser(logfname)
        self.shell.logfile = logfname

        loghead = '# IPython log file\n\n'
        try:
            logger.logstart(logfname, loghead, logmode, log_output, timestamp,
                            log_raw_input)
        except:
            self.shell.logfile = old_logfile
            warn("Couldn't start log: %s" % sys.exc_info()[1])
        else:
            # log input history up to this point, optionally interleaving
            # output if requested

            if timestamp:
                # disable timestamping for the previous history, since we've
                # lost those already (no time machine here).
                logger.timestamp = False

            if log_raw_input:
                input_hist = self.shell.history_manager.input_hist_raw
            else:
                input_hist = self.shell.history_manager.input_hist_parsed

            if log_output:
                log_write = logger.log_write
                output_hist = self.shell.history_manager.output_hist
                for n in range(1,len(input_hist)-1):
                    log_write(input_hist[n].rstrip() + '\n')
                    if n in output_hist:
                        log_write(repr(output_hist[n]),'output')
            else:
                logger.log_write('\n'.join(input_hist[1:]))
                logger.log_write('\n')
            if timestamp:
                # re-enable timestamping
                logger.timestamp = True

            print ('Activating auto-logging. '
                   'Current session state plus future input saved.')
            logger.logstate()

    @line_magic
    def logstop(self, parameter_s=''):
        """Fully stop logging and close log file.

        In order to start logging again, a new %logstart call needs to be made,
        possibly (though not necessarily) with a new filename, mode and other
        options."""
        self.logger.logstop()

    @line_magic
    def logoff(self, parameter_s=''):
        """Temporarily stop logging.

        You must have previously started logging."""
        self.shell.logger.switch_log(0)

    @line_magic
    def logon(self, parameter_s=''):
        """Restart logging.

        This function is for restarting logging which you've temporarily
        stopped with %logoff. For starting logging for the first time, you
        must use the %logstart function, which allows you to specify an
        optional log filename."""

        self.shell.logger.switch_log(1)

    @line_magic
    def logstate(self, parameter_s=''):
        """Print the status of the logging system."""

        self.shell.logger.logstate()


@register_magics
class ExtensionsMagics(Magics):
    """Magics to manage the IPython extensions system."""

    @line_magic
    def install_ext(self, parameter_s=''):
        """Download and install an extension from a URL, e.g.::

            %install_ext https://bitbucket.org/birkenfeld/ipython-physics/raw/d1310a2ab15d/physics.py

        The URL should point to an importable Python module - either a .py file
        or a .zip file.

        Parameters:

          -n filename : Specify a name for the file, rather than taking it from
                        the URL.
        """
        opts, args = self.parse_options(parameter_s, 'n:')
        try:
            filename = self.shell.extension_manager.install_extension(args,
                                                                 opts.get('n'))
        except ValueError as e:
            print e
            return

        filename = os.path.basename(filename)
        print "Installed %s. To use it, type:" % filename
        print "  %%load_ext %s" % os.path.splitext(filename)[0]


    @line_magic
    def load_ext(self, module_str):
        """Load an IPython extension by its module name."""
        return self.shell.extension_manager.load_extension(module_str)

    @line_magic
    def unload_ext(self, module_str):
        """Unload an IPython extension by its module name."""
        self.shell.extension_manager.unload_extension(module_str)

    @line_magic
    def reload_ext(self, module_str):
        """Reload an IPython extension by its module name."""
        self.shell.extension_manager.reload_extension(module_str)


@register_magics
class PylabMagics(Magics):
    """Magics related to matplotlib's pylab support"""

    @skip_doctest
    @line_magic
    def pylab(self, parameter_s=''):
        """Load numpy and matplotlib to work interactively.

        %pylab [GUINAME]

        This function lets you activate pylab (matplotlib, numpy and
        interactive support) at any point during an IPython session.

        It will import at the top level numpy as np, pyplot as plt, matplotlib,
        pylab and mlab, as well as all names from numpy and pylab.

        If you are using the inline matplotlib backend for embedded figures,
        you can adjust its behavior via the %config magic::

            # enable SVG figures, necessary for SVG+XHTML export in the qtconsole
            In [1]: %config InlineBackend.figure_format = 'svg'

            # change the behavior of closing all figures at the end of each
            # execution (cell), or allowing reuse of active figures across
            # cells:
            In [2]: %config InlineBackend.close_figures = False

        Parameters
        ----------
        guiname : optional
          One of the valid arguments to the %gui magic ('qt', 'wx', 'gtk',
          'osx' or 'tk').  If given, the corresponding Matplotlib backend is
          used, otherwise matplotlib's default (which you can override in your
          matplotlib config file) is used.

        Examples
        --------
        In this case, where the MPL default is TkAgg::

            In [2]: %pylab

            Welcome to pylab, a matplotlib-based Python environment.
            Backend in use: TkAgg
            For more information, type 'help(pylab)'.

        But you can explicitly request a different backend::

            In [3]: %pylab qt

            Welcome to pylab, a matplotlib-based Python environment.
            Backend in use: Qt4Agg
            For more information, type 'help(pylab)'.
        """

        if Application.initialized():
            app = Application.instance()
            try:
                import_all_status = app.pylab_import_all
            except AttributeError:
                import_all_status = True
        else:
            import_all_status = True

        self.shell.enable_pylab(parameter_s, import_all=import_all_status)


@register_magics
class DeprecatedMagics(Magics):
    """Magics slated for later removal."""

    @line_magic
    def install_profiles(self, parameter_s=''):
        """%install_profiles has been deprecated."""
        print '\n'.join([
            "%install_profiles has been deprecated.",
            "Use `ipython profile list` to view available profiles.",
            "Requesting a profile with `ipython profile create <name>`",
            "or `ipython --profile=<name>` will start with the bundled",
            "profile of that name if it exists."
        ])

    @line_magic
    def install_default_config(self, parameter_s=''):
        """%install_default_config has been deprecated."""
        print '\n'.join([
            "%install_default_config has been deprecated.",
            "Use `ipython profile create <name>` to initialize a profile",
            "with the default config files.",
            "Add `--reset` to overwrite already existing config files with defaults."
        ])