##// END OF EJS Templates
Renamed @register_magics to @magics_class to avoid confusion....
Renamed @register_magics to @magics_class to avoid confusion. The main ipython object also has a .register_magics method that must often be used in close proximity to the class decorator, yet does something completely different. Having these two objects with the same name yet different purposes was proving to be quite confusing in my testing usage so far.

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magic.py
437 lines | 16.0 KiB | text/x-python | PythonLexer
# encoding: utf-8
"""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
#-----------------------------------------------------------------------------
# Stdlib
import os
import re
import sys
import types
from getopt import getopt, GetoptError
# Our own
from IPython.config.configurable import Configurable
from IPython.core import oinspect
from IPython.core.error import UsageError
from IPython.core.prefilter import ESC_MAGIC
from IPython.external.decorator import decorator
from IPython.utils.ipstruct import Struct
from IPython.utils.process import arg_split
from IPython.utils.traitlets import Bool, Dict, Instance
from IPython.utils.warn import error, warn
#-----------------------------------------------------------------------------
# Globals
#-----------------------------------------------------------------------------
# A dict we'll use for each class that has magics, used as temporary storage to
# pass information between the @line/cell_magic method decorators and the
# @magics_class class decorator, because the method decorators have no
# access to the class when they run. See for more details:
# http://stackoverflow.com/questions/2366713/can-a-python-decorator-of-an-instance-method-access-the-class
magics = dict(line={}, cell={})
magic_types = ('line', 'cell')
magic_spec = ('line', 'cell', 'line_cell')
#-----------------------------------------------------------------------------
# Utility classes and functions
#-----------------------------------------------------------------------------
class Bunch: pass
def on_off(tag):
"""Return an ON/OFF string for a 1/0 input. Simple utility function."""
return ['OFF','ON'][tag]
def compress_dhist(dh):
head, tail = dh[:-10], dh[-10:]
newhead = []
done = set()
for h in head:
if h in done:
continue
newhead.append(h)
done.add(h)
return newhead + tail
def needs_local_scope(func):
"""Decorator to mark magic functions which need to local scope to run."""
func.needs_local_scope = True
return func
#-----------------------------------------------------------------------------
# Class and method decorators for registering magics
#-----------------------------------------------------------------------------
def magics_class(cls):
cls.registered = True
cls.magics = dict(line = magics['line'],
cell = magics['cell'])
magics['line'] = {}
magics['cell'] = {}
return cls
def record_magic(dct, mtype, mname, func):
if mtype == 'line_cell':
dct['line'][mname] = dct['cell'][mname] = func
else:
dct[mtype][mname] = func
def validate_type(magic_type):
if magic_type not in magic_spec:
raise ValueError('magic_type must be one of %s, %s given' %
magic_types, magic_type)
def _magic_marker(magic_type):
validate_type(magic_type)
# This is a closure to capture the magic_type. We could also use a class,
# but it's overkill for just that one bit of state.
def magic_deco(arg):
call = lambda f, *a, **k: f(*a, **k)
if callable(arg):
# "Naked" decorator call (just @foo, no args)
func = arg
name = func.func_name
func.magic_name = name
retval = decorator(call, func)
record_magic(magics, magic_type, name, name)
elif isinstance(arg, basestring):
# Decorator called with arguments (@foo('bar'))
name = arg
def mark(func, *a, **kw):
func.magic_name = name
record_magic(magics, magic_type, name, func.func_name)
return decorator(call, func)
retval = mark
else:
raise ValueError("Decorator can only be called with "
"string or function")
return retval
return magic_deco
def _function_magic_marker(magic_type):
validate_type(magic_type)
# This is a closure to capture the magic_type. We could also use a class,
# but it's overkill for just that one bit of state.
def magic_deco(arg):
call = lambda f, *a, **k: f(*a, **k)
# Find get_ipython() in the caller's namespace
caller = sys._getframe(1)
for ns in ['f_locals', 'f_globals', 'f_builtins']:
get_ipython = getattr(caller, ns).get('get_ipython')
if get_ipython is not None:
break
else:
raise('Decorator can only run in context where `get_ipython` exists')
ip = get_ipython()
if callable(arg):
# "Naked" decorator call (just @foo, no args)
func = arg
#name = func.func_name
#func.magic_name = name
ip.register_magic_function(func)
retval = decorator(call, func)
elif isinstance(arg, basestring):
# Decorator called with arguments (@foo('bar'))
name = arg
def mark(func, *a, **kw):
#func.magic_name = name
ip.register_magic_function(func)
return decorator(call, func)
retval = mark
else:
raise ValueError("Decorator can only be called with "
"string or function")
return retval
return magic_deco
# Create the actual decorators for public use
# These three are used to decorate methods in class definitions
line_magic = _magic_marker('line')
cell_magic = _magic_marker('cell')
line_cell_magic = _magic_marker('line_cell')
# These three decorate standalone functions and perform the decoration
# immediately. They can only run where get_ipython() works
register_line_magic = _function_magic_marker('line')
register_cell_magic = _function_magic_marker('cell')
register_line_cell_magic = _function_magic_marker('line_cell')
#-----------------------------------------------------------------------------
# Core Magic classes
#-----------------------------------------------------------------------------
class MagicsManager(Configurable):
"""Object that handles all magic-related functionality for IPython.
"""
# Non-configurable class attributes
# A two-level dict, first keyed by magic type, then by magic function, and
# holding the actual callable object as value. This is the dict used for
# magic function dispatch
magics = Dict
# A registry of the original objects that we've been given holding magics.
registry = Dict
shell = Instance('IPython.core.interactiveshell.InteractiveShellABC')
auto_magic = Bool
_auto_status = [
'Automagic is OFF, % prefix IS needed for magic functions.',
'Automagic is ON, % prefix IS NOT needed for magic functions.']
user_magics = Instance('IPython.core.magics.UserMagics')
def __init__(self, shell=None, config=None, user_magics=None, **traits):
super(MagicsManager, self).__init__(shell=shell, config=config,
user_magics=user_magics, **traits)
self.magics = dict(line={}, cell={})
# Let's add the user_magics to the registry for uniformity, so *all*
# registered magic containers can be found there.
self.registry[user_magics.__class__.__name__] = user_magics
def auto_status(self):
"""Return descriptive string with automagic status."""
return self._auto_status[self.auto_magic]
def lsmagic(self):
"""Return a dict of currently available magic functions.
The return dict has the keys 'line' and 'cell', corresponding to the
two types of magics we support. Each value is a list of names.
"""
return self.magics
def register(self, *magic_objects):
"""Register one or more instances of Magics.
"""
# Start by validating them to ensure they have all had their magic
# methods registered at the instance level
for m in magic_objects:
if not m.registered:
raise ValueError("Class of magics %r was constructed without "
"the @register_macics class decorator")
if type(m) is type:
# If we're given an uninstantiated class
m = m(self.shell)
# Now that we have an instance, we can register it and update the
# table of callables
self.registry[m.__class__.__name__] = m
for mtype in magic_types:
self.magics[mtype].update(m.magics[mtype])
def register_function(self, func, magic_type='line', magic_name=None):
"""Expose a standalone function as magic function for ipython.
"""
# Create the new method in the user_magics and register it in the
# global table
validate_type(magic_type)
magic_name = func.func_name if magic_name is None else magic_name
setattr(self.user_magics, magic_name, func)
record_magic(self.magics, magic_type, magic_name, func)
def define_magic(self, name, func):
"""Support for deprecated API.
This method exists only to support the old-style definition of magics.
It will eventually be removed. Deliberately not documented further.
"""
meth = types.MethodType(func, self.user_magics)
setattr(self.user_magics, name, meth)
record_magic(self.magics, 'line', name, meth)
# Key base class that provides the central functionality for magics.
class Magics(object):
"""Base class for implementing magic functions.
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("../")`
Classes providing magic functions need to subclass this class, and they
MUST:
- Use the method decorators `@line_magic` and `@cell_magic` to decorate
individual methods as magic functions, AND
- Use the class decorator `@magics_class` to ensure that the magic
methods are properly registered at the instance level upon instance
initialization.
See :mod:`magic_functions` for examples of actual implementation classes.
"""
# Dict holding all command-line options for each magic.
options_table = None
# Dict for the mapping of magic names to methods, set by class decorator
magics = None
# Flag to check that the class decorator was properly applied
registered = False
# Instance of IPython shell
shell = None
def __init__(self, shell):
if not(self.__class__.registered):
raise ValueError('Magics subclass without registration - '
'did you forget to apply @magics_class?')
self.shell = shell
self.options_table = {}
# The method decorators are run when the instance doesn't exist yet, so
# they can only record the names of the methods they are supposed to
# grab. Only now, that the instance exists, can we create the proper
# mapping to bound methods. So we read the info off the original names
# table and replace each method name by the actual bound method.
for mtype in magic_types:
tab = self.magics[mtype]
# must explicitly use keys, as we're mutating this puppy
for magic_name in tab.keys():
meth_name = tab[magic_name]
if isinstance(meth_name, basestring):
tab[magic_name] = getattr(self, meth_name)
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,
re.MULTILINE)
# Magic commands
cmd_re = re.compile(r'(?P<cmd>%s.+?\b)(?!\}\}:)' % ESC_MAGIC,
re.MULTILINE)
# 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)
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 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.
Options:
-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
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', os.name == 'posix')
strict = kw.get('strict', 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, strict)
# Do regular option processing
try:
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:]
else:
o = o[1:]
try:
odict[o].append(a)
except AttributeError:
odict[o] = [odict[o],a]
except KeyError:
if list_all:
odict[o] = [a]
else:
odict[o] = a
# Prepare opts,args for return
opts = Struct(odict)
if mode == 'string':
args = ' '.join(args)
return opts,args
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