##// END OF EJS Templates
Massive amount of work to improve the test suite, restores doctests....
Massive amount of work to improve the test suite, restores doctests. After Brian's comments, I realized that our test machinery was NOT in reality running all the ipython-syntax doctests we have. This is now fixed. The test suite isn't completely passing, but this commit is for the underlying machinery. I will now work on fixing as many broken tests as I can. Fixes https://bugs.launchpad.net/ipython/+bug/505071

File last commit:

Show More
3612 lines | 135.5 KiB | text/x-python | PythonLexer
# -*- coding: utf-8 -*-
"""Magic functions for InteractiveShell.
# Copyright (C) 2001 Janko Hauser <jhauser@zscout.de> and
# Copyright (C) 2001-2006 Fernando Perez <fperez@colorado.edu>
# Distributed under the terms of the BSD License. The full license is in
# the file COPYING, distributed as part of this software.
# Modules and globals
# Python standard modules
import __builtin__
import bdb
import inspect
import os
import pdb
import pydoc
import sys
import shutil
import re
import tempfile
import time
import cPickle as pickle
import textwrap
from cStringIO import StringIO
from getopt import getopt,GetoptError
from pprint import pprint, pformat
# cProfile was added in Python2.5
import cProfile as profile
import pstats
except ImportError:
# profile isn't bundled by default in Debian for license reasons
import profile,pstats
except ImportError:
profile = pstats = None
# Homebrewed
import IPython
import IPython.utils.generics
from IPython.core import debugger, oinspect
from IPython.core.error import TryNext
from IPython.core.error import UsageError
from IPython.core.fakemodule import FakeModule
from IPython.core.macro import Macro
from IPython.core.page import page
from IPython.core.prefilter import ESC_MAGIC
from IPython.core.pylabtools import mpl_runner
from IPython.lib.inputhook import enable_gui
from IPython.external.Itpl import Itpl, itpl, printpl,itplns
from IPython.testing import decorators as testdec
from IPython.utils import platutils
from IPython.utils import wildcard
from IPython.utils.PyColorize import Parser
from IPython.utils.ipstruct import Struct
# XXX - We need to switch to explicit imports here with genutils
from IPython.utils.genutils import *
# Utility functions
def on_off(tag):
"""Return an ON/OFF string for a 1/0 input. Simple utility function."""
return ['OFF','ON'][tag]
class Bunch: pass
def compress_dhist(dh):
head, tail = dh[:-10], dh[-10:]
newhead = []
done = set()
for h in head:
if h in done:
return newhead + tail
# Main class implementing Magic functionality
# XXX - for some odd reason, if Magic is made a new-style class, we get errors
# on construction of the main InteractiveShell object. Something odd is going
# on with super() calls, Component and the MRO... For now leave it as-is, but
# eventually this needs to be clarified.
class Magic:
"""Magic functions for InteractiveShell.
Shell functions which can be reached as %function_name. All magic
functions should accept a string, which they can parse for their own
needs. This can make some functions easier to type, eg `%cd ../`
vs. `%cd("../")`
ALL definitions MUST begin with the prefix magic_. The user won't need it
at the command line, but it is is needed in the definition. """
# class globals
auto_status = ['Automagic is OFF, % prefix IS needed for magic functions.',
'Automagic is ON, % prefix NOT needed for magic functions.']
# some utility functions
def __init__(self,shell):
self.options_table = {}
if profile is None:
self.magic_prun = self.profile_missing_notice
self.shell = shell
# namespace for holding state we may need
self._magic_state = Bunch()
def profile_missing_notice(self, *args, **kwargs):
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.""")
def default_option(self,fn,optstr):
"""Make an entry in the options_table for fn, with value optstr"""
if fn not in self.lsmagic():
error("%s is not a magic function" % fn)
self.options_table[fn] = optstr
def lsmagic(self):
"""Return a list of currently available magic functions.
Gives a list of the bare names after mangling (['ls','cd', ...], not
# FIXME. This needs a cleanup, in the way the magics list is built.
# magics in class definition
class_magic = lambda fn: fn.startswith('magic_') and \
# in instance namespace (run-time user additions)
inst_magic = lambda fn: fn.startswith('magic_') and \
# and bound magics by user (so they can access self):
inst_bound_magic = lambda fn: fn.startswith('magic_') and \
magics = filter(class_magic,Magic.__dict__.keys()) + \
filter(inst_magic,self.__dict__.keys()) + \
out = []
for fn in set(magics):
return out
def extract_input_slices(self,slices,raw=False):
"""Return as a string a set of input history slices.
- slices: the set of slices is given as a list of strings (like
['1','4:8','9'], since this function is for use by magic functions
which get their arguments as strings.
Optional inputs:
- raw(False): by default, the processed input is used. If this is
true, the raw input history is used instead.
Note that slices can be called with two notations:
N:M -> standard python form, means including items N...(M-1).
N-M -> include items N..M (closed endpoint)."""
if raw:
hist = self.shell.input_hist_raw
hist = self.shell.input_hist
cmds = []
for chunk in slices:
if ':' in chunk:
ini,fin = map(int,chunk.split(':'))
elif '-' in chunk:
ini,fin = map(int,chunk.split('-'))
fin += 1
ini = int(chunk)
fin = ini+1
return cmds
def _ofind(self, oname, namespaces=None):
"""Find an object in the available namespaces.
self._ofind(oname) -> dict with keys: found,obj,ospace,ismagic
Has special code to detect magic functions.
oname = oname.strip()
alias_ns = None
if namespaces is None:
# Namespaces to search in:
# Put them in a list. The order is important so that we
# find things in the same order that Python finds them.
namespaces = [ ('Interactive', self.shell.user_ns),
('IPython internal', self.shell.internal_ns),
('Python builtin', __builtin__.__dict__),
('Alias', self.shell.alias_manager.alias_table),
alias_ns = self.shell.alias_manager.alias_table
# initialize results to 'null'
found = 0; obj = None; ospace = None; ds = None;
ismagic = 0; isalias = 0; parent = None
# Look for the given name by splitting it in parts. If the head is
# found, then we look for all the remaining parts as members, and only
# declare success if we can find them all.
oname_parts = oname.split('.')
oname_head, oname_rest = oname_parts[0],oname_parts[1:]
for nsname,ns in namespaces:
obj = ns[oname_head]
except KeyError:
#print 'oname_rest:', oname_rest # dbg
for part in oname_rest:
parent = obj
obj = getattr(obj,part)
# Blanket except b/c some badly implemented objects
# allow __getattr__ to raise exceptions other than
# AttributeError, which then crashes IPython.
# If we finish the for loop (no break), we got all members
found = 1
ospace = nsname
if ns == alias_ns:
isalias = 1
break # namespace loop
# Try to see if it's magic
if not found:
if oname.startswith(ESC_MAGIC):
oname = oname[1:]
obj = getattr(self,'magic_'+oname,None)
if obj is not None:
found = 1
ospace = 'IPython internal'
ismagic = 1
# Last try: special-case some literals like '', [], {}, etc:
if not found and oname_head in ["''",'""','[]','{}','()']:
obj = eval(oname_head)
found = 1
ospace = 'Interactive'
return {'found':found, 'obj':obj, 'namespace':ospace,
'ismagic':ismagic, 'isalias':isalias, 'parent':parent}
def arg_err(self,func):
"""Print docstring if incorrect arguments were passed"""
print 'Error in arguments:'
print OInspect.getdoc(func)
def format_latex(self,strng):
"""Format a string for latex inclusion."""
# Characters that need to be escaped for latex:
escape_re = re.compile(r'(%|_|\$|#|&)',re.MULTILINE)
# Magic command names as headers:
cmd_name_re = re.compile(r'^(%s.*?):' % ESC_MAGIC,
# Magic commands
cmd_re = re.compile(r'(?P<cmd>%s.+?\b)(?!\}\}:)' % ESC_MAGIC,
# Paragraph continue
par_re = re.compile(r'\\$',re.MULTILINE)
# The "\n" symbol
newline_re = re.compile(r'\\n')
# Now build the string for output:
#strng = cmd_name_re.sub(r'\n\\texttt{\\textsl{\\large \1}}:',strng)
strng = cmd_name_re.sub(r'\n\\bigskip\n\\texttt{\\textbf{ \1}}:',
strng = cmd_re.sub(r'\\texttt{\g<cmd>}',strng)
strng = par_re.sub(r'\\\\',strng)
strng = escape_re.sub(r'\\\1',strng)
strng = newline_re.sub(r'\\textbackslash{}n',strng)
return strng
def format_screen(self,strng):
"""Format a string for screen printing.
This removes some latex-type format codes."""
# Paragraph continue
par_re = re.compile(r'\\$',re.MULTILINE)
strng = par_re.sub('',strng)
return strng
def parse_options(self,arg_str,opt_str,*long_opts,**kw):
"""Parse options passed to an argument string.
The interface is similar to that of getopt(), but it returns back a
Struct with the options as keys and the stripped argument string still
as a string.
arg_str is quoted as a true sys.argv vector by using shlex.split.
This allows us to easily expand variables, glob files, quote
arguments, etc.
-mode: default 'string'. If given as 'list', the argument string is
returned as a list (split on whitespace) instead of a string.
-list_all: put all option values in lists. Normally only options
appearing more than once are put in a list.
-posix (True): whether to split the input line in POSIX mode or not,
as per the conventions outlined in the shlex module from the
standard library."""
# inject default options at the beginning of the input line
caller = sys._getframe(1).f_code.co_name.replace('magic_','')
arg_str = '%s %s' % (self.options_table.get(caller,''),arg_str)
mode = kw.get('mode','string')
if mode not in ['string','list']:
raise ValueError,'incorrect mode given: %s' % mode
# Get options
list_all = kw.get('list_all',0)
posix = kw.get('posix',True)
# Check if we have more than one argument to warrant extra processing:
odict = {} # Dictionary with options
args = arg_str.split()
if len(args) >= 1:
# If the list of inputs only has 0 or 1 thing in it, there's no
# need to look for options
argv = arg_split(arg_str,posix)
# Do regular option processing
opts,args = getopt(argv,opt_str,*long_opts)
except GetoptError,e:
raise UsageError('%s ( allowed: "%s" %s)' % (e.msg,opt_str,
" ".join(long_opts)))
for o,a in opts:
if o.startswith('--'):
o = o[2:]
o = o[1:]
except AttributeError:
odict[o] = [odict[o],a]
except KeyError:
if list_all:
odict[o] = [a]
odict[o] = a
# Prepare opts,args for return
opts = Struct(odict)
if mode == 'string':
args = ' '.join(args)
return opts,args
# And now the actual magic functions
# Functions for IPython shell work (vars,funcs, config, etc)
def magic_lsmagic(self, parameter_s = ''):
"""List currently available magic functions."""
mesc = ESC_MAGIC
print 'Available magic functions:\n'+mesc+\
(' '+mesc).join(self.lsmagic())
print '\n' + Magic.auto_status[self.shell.automagic]
return None
def magic_magic(self, parameter_s = ''):
"""Print information about the magic function system.
Supported formats: -latex, -brief, -rest
mode = ''
if parameter_s.split()[0] == '-latex':
mode = 'latex'
if parameter_s.split()[0] == '-brief':
mode = 'brief'
if parameter_s.split()[0] == '-rest':
mode = 'rest'
rest_docs = []
magic_docs = []
for fname in self.lsmagic():
mname = 'magic_' + fname
for space in (Magic,self,self.__class__):
fn = space.__dict__[mname]
except KeyError:
if mode == 'brief':
# only first line
if fn.__doc__:
fndoc = fn.__doc__.split('\n',1)[0]
fndoc = 'No documentation'
if fn.__doc__:
fndoc = fn.__doc__.rstrip()
fndoc = 'No documentation'
if mode == 'rest':
rest_docs.append('**%s%s**::\n\n\t%s\n\n' %(ESC_MAGIC,
magic_docs.append('%s%s:\n\t%s\n' %(ESC_MAGIC,
magic_docs = ''.join(magic_docs)
if mode == 'rest':
return "".join(rest_docs)
if mode == 'latex':
print self.format_latex(magic_docs)
magic_docs = self.format_screen(magic_docs)
if mode == 'brief':
return magic_docs
outmsg = """
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.
You can define your own magic functions to extend the system. See the supplied
ipythonrc and example-magic.py files for details (in your ipython
configuration directory, typically $HOME/.ipython/).
You can also define your own aliased names for magic functions. In your
ipythonrc file, placing a line like:
execute __IPYTHON__.magic_pf = __IPYTHON__.magic_profile
will define %pf as a new name for %profile.
You can also call magics in code using the magic() function, which IPython
automatically adds to the builtin namespace. Type 'magic?' for details.
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:\n"""
mesc = ESC_MAGIC
outmsg = ("%s\n%s\n\nSummary of magic functions (from %slsmagic):"
"\n\n%s%s\n\n%s" % (outmsg,
(' '+mesc).join(self.lsmagic()),
Magic.auto_status[self.shell.automagic] ) )
def magic_autoindent(self, parameter_s = ''):
"""Toggle autoindent on/off (if available)."""
print "Automatic indentation is:",['OFF','ON'][self.shell.autoindent]
def magic_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()
if parameter_s in ('on','1','true'):
self.shell.automagic = True
elif parameter_s in ('off','0','false'):
self.shell.automagic = False
self.shell.automagic = not self.shell.automagic
print '\n' + Magic.auto_status[self.shell.automagic]
def magic_autocall(self, parameter_s = ''):
"""Make functions callable without having to type parentheses.
%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)
arg = 'toggle'
if not arg in (0,1,2,'toggle'):
error('Valid modes: (0->Off, 1->Smart, 2->Full')
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
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]
def magic_system_verbose(self, parameter_s = ''):
"""Set verbose printing of system calls.
If called without an argument, act as a toggle"""
if parameter_s:
val = bool(eval(parameter_s))
val = None
if self.shell.system_verbose:
self.shell.system_verbose = False
self.shell.system_verbose = True
print "System verbose printing is:",\
def magic_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).
-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'] )
print 'Object `%s` not found' % oname
def magic_profile(self, parameter_s=''):
"""Print your currently active IPyhton profile."""
if self.shell.profile:
printpl('Current IPython profile: $self.shell.profile.')
print 'No profile active.'
def magic_pinfo(self, parameter_s='', namespaces=None):
"""Provide detailed information about an object.
'%pinfo object' is just a synonym for object? or ?object."""
#print 'pinfo par: <%s>' % parameter_s # dbg
# detail_level: 0 -> obj? , 1 -> obj??
detail_level = 0
# We need to detect if we got called as 'pinfo pinfo foo', which can
# happen if the user types 'pinfo foo?' at the cmd line.
pinfo,qmark1,oname,qmark2 = \
re.match('(pinfo )?(\?*)(.*?)(\??$)',parameter_s).groups()
if pinfo or qmark1 or qmark2:
detail_level = 1
if "*" in oname:
self._inspect('pinfo', oname, detail_level=detail_level,
def magic_pdef(self, parameter_s='', namespaces=None):
"""Print the definition header for any callable object.
If the object is a class, print the constructor information."""
self._inspect('pdef',parameter_s, namespaces)
def magic_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)
def magic_psource(self, parameter_s='', namespaces=None):
"""Print (or run through pager) the source code for an object."""
self._inspect('psource',parameter_s, namespaces)
def magic_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
# 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':
filename = get_py_filename(parameter_s)
except IOError,msg:
print msg
def _inspect(self,meth,oname,namespaces=None,**kw):
"""Generic interface to the inspector system.
This function is meant to be called by pdef, pdoc & friends."""
#oname = oname.strip()
#print '1- oname: <%r>' % oname # dbg
oname = oname.strip().encode('ascii')
#print '2- oname: <%r>' % oname # dbg
except UnicodeEncodeError:
print 'Python identifiers can only contain ascii characters.'
return 'not found'
info = Struct(self._ofind(oname, namespaces))
if info.found:
except TryNext:
# Get the docstring of the class property if it exists.
path = oname.split('.')
root = '.'.join(path[:-1])
if info.parent is not None:
target = getattr(info.parent, '__class__')
# The object belongs to a class instance.
target = getattr(target, path[-1])
# The class defines the object.
if isinstance(target, property):
oname = root + '.__class__.' + path[-1]
info = Struct(self._ofind(oname))
except AttributeError: pass
except AttributeError: pass
pmethod = getattr(self.shell.inspector,meth)
formatter = info.ismagic and self.format_screen or None
if meth == 'pdoc':
elif meth == 'pinfo':
print 'Object `%s` not found.' % oname
return 'not found' # so callers can take other action
def magic_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
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.
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).
-a: makes the pattern match even objects whose names start with a
single underscore. These names are normally ommitted from the
-i/-c: make the pattern case insensitive/sensitive. If neither of
these options is given, the default is read from your ipythonrc
file. The option name which sets this value is
'wildcards_case_sensitive'. If this option is not specified in your
ipythonrc file, IPython's internal default is to do a case sensitive
-e/-s NAMESPACE: exclude/search a given namespace. The pattern you
specifiy 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).
%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 sensitve 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"""
parameter_s = parameter_s.encode('ascii')
except UnicodeEncodeError:
print 'Python identifiers can only contain ascii characters.'
# default namespaces to be searched
def_search = ['user','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
ignore_case = not shell.wildcards_case_sensitive
# Build list of namespaces to search from user options
ns_exclude = ns_exclude=opt('e',[])
ns_search = [nm for nm in def_search if nm not in ns_exclude]
# Call the actual search
def magic_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."""
user_ns = self.shell.user_ns
internal_ns = self.shell.internal_ns
user_config_ns = self.shell.user_config_ns
out = [ i for i in user_ns
if not i.startswith('_') \
and not (i in internal_ns or i in user_config_ns) ]
typelist = parameter_s.split()
if typelist:
typeset = set(typelist)
out = [i for i in out if type(i).__name__ in typeset]
return out
def magic_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."""
varlist = self.magic_who_ls(parameter_s)
if not varlist:
if parameter_s:
print 'No variables match your requested type.'
print 'Interactive namespace is empty.'
# if we have variables, move on...
count = 0
for i in varlist:
print i+'\t',
count += 1
if count > 8:
count = 0
def magic_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 and Numeric arrays, a summary with shape, number of
elements, typecode and size in memory.
- Everything else: a string representation, snipping their middle if
too long."""
varnames = self.magic_who_ls(parameter_s)
if not varnames:
if parameter_s:
print 'No variables match your requested type.'
print 'Interactive namespace is empty.'
# if we have variables, move on...
# for these types, show len() instead of data:
seq_types = [types.DictType,types.ListType,types.TupleType]
# for numpy/Numeric arrays, display summary info
import numpy
except ImportError:
ndarray_type = None
ndarray_type = numpy.ndarray.__name__
import Numeric
except ImportError:
array_type = None
array_type = Numeric.ArrayType.__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__),
# column labels and # of spaces as separator
varlabel = 'Variable'
typelabel = 'Type'
datalabel = 'Data/Info'
colsep = 3
# variable format strings
vformat = "$vname.ljust(varwidth)$vtype.ljust(typewidth)"
vfmt_short = '$vstr[:25]<...>$vstr[-25:]'
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 itpl(vformat),
if vtype in seq_types:
print len(var)
elif vtype in [array_type,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
# Numeric
vsize = Numeric.size(var)
vbytes = vsize*var.itemsize()
vdtype = var.typecode()
if vbytes < 100000:
print aformat % (vshape,vsize,vdtype,vbytes)
print aformat % (vshape,vsize,vdtype,vbytes),
if vbytes < Mb:
print '(%s kb)' % (vbytes/kb,)
print '(%s Mb)' % (vbytes/Mb,)
vstr = str(var)
except UnicodeEncodeError:
vstr = unicode(var).encode(sys.getdefaultencoding(),
vstr = vstr.replace('\n','\\n')
if len(vstr) < 50:
print vstr
def magic_reset(self, parameter_s=''):
"""Resets the namespace by removing all names defined by the user.
Input/Output history are left around in case you need them.
-y : force reset without asking for confirmation.
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 [10]: 'a' in _ip.user_ns
Out[10]: False
if parameter_s == '-f':
ans = True
ans = self.shell.ask_yes_no(
"Once deleted, variables cannot be recovered. Proceed (y/[n])? ")
if not ans:
print 'Nothing done.'
user_ns = self.shell.user_ns
for i in self.magic_who_ls():
# Also flush the private list of module references kept for script
# execution protection
def magic_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.
-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
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
# ipytohn remain valid
if par:
logfname,logmode = par.split()
logfname = par
logmode = 'backup'
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'
started = logger.logstart(logfname,loghead,logmode,
rc.opts.logfile = old_logfile
warn("Couldn't start log: %s" % sys.exc_info()[1])
# 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.input_hist_raw
input_hist = self.shell.input_hist
if log_output:
log_write = logger.log_write
output_hist = self.shell.output_hist
for n in range(1,len(input_hist)-1):
if n in output_hist:
if timestamp:
# re-enable timestamping
logger.timestamp = True
print ('Activating auto-logging. '
'Current session state plus future input saved.')
def magic_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
def magic_logoff(self,parameter_s=''):
"""Temporarily stop logging.
You must have previously started logging."""
def magic_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."""
def magic_logstate(self,parameter_s=''):
"""Print the status of the logging system."""
def magic_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 ipythonrc
configuration file (the variable is called '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:
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.')
# 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)
def magic_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.
def magic_prun(self, parameter_s ='',user_mode=1,
"""Run a statement through the python code profiler.
%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.
-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
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 understod 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.
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=[''])
# protect user quote marks
parameter_s = parameter_s.replace('"',r'\"').replace("'",r"\'")
if user_mode: # regular user call
opts,arg_str = self.parse_options(parameter_s,'D:l:rs:T:',
namespace = self.shell.user_ns
else: # called to run a program by %run -p
filename = get_py_filename(arg_lst[0])
except IOError,msg:
arg_str = 'execfile(filename,prog_ns)'
namespace = locals()
prof = profile.Profile()
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:
except ValueError:
except ValueError:
# 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
# For older versions, we manually redirect stdout during printing
sys_stdout = sys.stdout
sys.stdout = stdout_trap
sys.stdout = sys_stdout
output = stdout_trap.getvalue()
output = output.rstrip()
print sys_exit,
dump_file = opts.D[0]
text_file = opts.T[0]
if dump_file:
print '\n*** Profile stats marshalled to file',\
if text_file:
pfile = file(text_file,'w')
print '\n*** Profile printout saved to text file',\
if opts.has_key('r'):
return stats
return None
def magic_run(self, parameter_s ='',runner=None,
"""Run the named file inside IPython as a program.
%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
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.
-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:
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 qoutes) to start execution up to the first
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.
# 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:e',
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)
except IOError,msg:
if filename.lower().endswith('.ipy'):
# Control the response to exit() calls made by the script being run
exit_ignore = opts.has_key('e')
# 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
sys.argv = [filename]+ arg_lst[1:] # put in the proper filename
if opts.has_key('i'):
# 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)
# Run in a fresh, empty namespace
if opts.has_key('n'):
name = os.path.splitext(os.path.basename(filename))[0]
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 iplib 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__']
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
stats = None
if opts.has_key('p'):
stats = self.magic_prun('',0,opts,arg_lst,prog_ns)
if opts.has_key('d'):
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):
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)
# 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
deb.run('execfile("%s")' % filename,prog_ns)
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).
if runner is None:
runner = self.shell.safe_execfile
if opts.has_key('t'):
# timed execution
nruns = int(opts['N'][0])
if nruns < 1:
error('Number of runs must be >=1')
except (KeyError):
nruns = 1
if nruns == 1:
t0 = clock2()
t1 = clock2()
t_usr = t1[0]-t0[0]
t_sys = t1[1]-t0[1]
print "\nIPython CPU timings (estimated):"
print " User : %10s s." % t_usr
print " System: %10s s." % t_sys
runs = range(nruns)
t0 = clock2()
for nr in runs:
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 : %10s %10s" % ('Total','Per run')
print " User : %10s s, %10s s." % (t_usr,t_usr/nruns)
print " System: %10s s, %10s s." % (t_sys,t_sys/nruns)
# regular execution
if opts.has_key('i'):
self.shell.user_ns['__name__'] = __name__save
# 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).
# 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)
# 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__
# Ensure key global structures are restored
sys.argv = save_argv
if restore_main:
sys.modules['__main__'] = restore_main
# 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
def magic_timeit(self, parameter_s =''):
"""Time execution of a Python statement or expression
%timeit [-n<N> -r<R> [-t|-c]] statement
Time execution of a Python statement or expression using the timeit
-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
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:',
if stmt == "":
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:
number *= 10
best = min(timer.repeat(repeat, number)) / number
if best > 0.0:
order = min(-int(math.floor(math.log10(best)) // 3), 3)
order = 3
print u"%d loops, best of %d: %.*g %s per loop" % (number, repeat,
best * scaling[order],
if tc > tc_min:
print "Compiler time: %.2f s" % tc
def magic_time(self,parameter_s = ''):
"""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).
Some 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