##// END OF EJS Templates
Make copy of notebook node object to make sure the source doesn't get modified
Make copy of notebook node object to make sure the source doesn't get modified

File last commit:

r11124:9567c77a
r11375:410cedc0
Show More
oinspect.py
882 lines | 29.3 KiB | text/x-python | PythonLexer
# -*- coding: utf-8 -*-
"""Tools for inspecting Python objects.
Uses syntax highlighting for presenting the various information elements.
Similar in spirit to the inspect module, but all calls take a name argument to
reference the name under which an object is being read.
"""
#*****************************************************************************
# Copyright (C) 2001-2004 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.
#*****************************************************************************
from __future__ import print_function
__all__ = ['Inspector','InspectColors']
# stdlib modules
import inspect
import linecache
import os
import types
import io as stdlib_io
try:
from itertools import izip_longest
except ImportError:
from itertools import zip_longest as izip_longest
# IPython's own
from IPython.core import page
from IPython.testing.skipdoctest import skip_doctest_py3
from IPython.utils import PyColorize
from IPython.utils import io
from IPython.utils import openpy
from IPython.utils import py3compat
from IPython.utils.text import indent
from IPython.utils.wildcard import list_namespace
from IPython.utils.coloransi import *
from IPython.utils.py3compat import cast_unicode
#****************************************************************************
# Builtin color schemes
Colors = TermColors # just a shorthand
# Build a few color schemes
NoColor = ColorScheme(
'NoColor',{
'header' : Colors.NoColor,
'normal' : Colors.NoColor # color off (usu. Colors.Normal)
} )
LinuxColors = ColorScheme(
'Linux',{
'header' : Colors.LightRed,
'normal' : Colors.Normal # color off (usu. Colors.Normal)
} )
LightBGColors = ColorScheme(
'LightBG',{
'header' : Colors.Red,
'normal' : Colors.Normal # color off (usu. Colors.Normal)
} )
# Build table of color schemes (needed by the parser)
InspectColors = ColorSchemeTable([NoColor,LinuxColors,LightBGColors],
'Linux')
#****************************************************************************
# Auxiliary functions and objects
# See the messaging spec for the definition of all these fields. This list
# effectively defines the order of display
info_fields = ['type_name', 'base_class', 'string_form', 'namespace',
'length', 'file', 'definition', 'docstring', 'source',
'init_definition', 'class_docstring', 'init_docstring',
'call_def', 'call_docstring',
# These won't be printed but will be used to determine how to
# format the object
'ismagic', 'isalias', 'isclass', 'argspec', 'found', 'name'
]
def object_info(**kw):
"""Make an object info dict with all fields present."""
infodict = dict(izip_longest(info_fields, [None]))
infodict.update(kw)
return infodict
def get_encoding(obj):
"""Get encoding for python source file defining obj
Returns None if obj is not defined in a sourcefile.
"""
ofile = find_file(obj)
# run contents of file through pager starting at line where the object
# is defined, as long as the file isn't binary and is actually on the
# filesystem.
if ofile is None:
return None
elif ofile.endswith(('.so', '.dll', '.pyd')):
return None
elif not os.path.isfile(ofile):
return None
else:
# Print only text files, not extension binaries. Note that
# getsourcelines returns lineno with 1-offset and page() uses
# 0-offset, so we must adjust.
buffer = stdlib_io.open(ofile, 'rb') # Tweaked to use io.open for Python 2
encoding, lines = openpy.detect_encoding(buffer.readline)
return encoding
def getdoc(obj):
"""Stable wrapper around inspect.getdoc.
This can't crash because of attribute problems.
It also attempts to call a getdoc() method on the given object. This
allows objects which provide their docstrings via non-standard mechanisms
(like Pyro proxies) to still be inspected by ipython's ? system."""
# Allow objects to offer customized documentation via a getdoc method:
try:
ds = obj.getdoc()
except Exception:
pass
else:
# if we get extra info, we add it to the normal docstring.
if isinstance(ds, basestring):
return inspect.cleandoc(ds)
try:
docstr = inspect.getdoc(obj)
encoding = get_encoding(obj)
return py3compat.cast_unicode(docstr, encoding=encoding)
except Exception:
# Harden against an inspect failure, which can occur with
# SWIG-wrapped extensions.
raise
return None
def getsource(obj,is_binary=False):
"""Wrapper around inspect.getsource.
This can be modified by other projects to provide customized source
extraction.
Inputs:
- obj: an object whose source code we will attempt to extract.
Optional inputs:
- is_binary: whether the object is known to come from a binary source.
This implementation will skip returning any output for binary objects, but
custom extractors may know how to meaningfully process them."""
if is_binary:
return None
else:
# get source if obj was decorated with @decorator
if hasattr(obj,"__wrapped__"):
obj = obj.__wrapped__
try:
src = inspect.getsource(obj)
except TypeError:
if hasattr(obj,'__class__'):
src = inspect.getsource(obj.__class__)
encoding = get_encoding(obj)
return cast_unicode(src, encoding=encoding)
def getargspec(obj):
"""Get the names and default values of a function's arguments.
A tuple of four things is returned: (args, varargs, varkw, defaults).
'args' is a list of the argument names (it may contain nested lists).
'varargs' and 'varkw' are the names of the * and ** arguments or None.
'defaults' is an n-tuple of the default values of the last n arguments.
Modified version of inspect.getargspec from the Python Standard
Library."""
if inspect.isfunction(obj):
func_obj = obj
elif inspect.ismethod(obj):
func_obj = obj.im_func
elif hasattr(obj, '__call__'):
func_obj = obj.__call__
else:
raise TypeError('arg is not a Python function')
args, varargs, varkw = inspect.getargs(func_obj.func_code)
return args, varargs, varkw, func_obj.func_defaults
def format_argspec(argspec):
"""Format argspect, convenience wrapper around inspect's.
This takes a dict instead of ordered arguments and calls
inspect.format_argspec with the arguments in the necessary order.
"""
return inspect.formatargspec(argspec['args'], argspec['varargs'],
argspec['varkw'], argspec['defaults'])
def call_tip(oinfo, format_call=True):
"""Extract call tip data from an oinfo dict.
Parameters
----------
oinfo : dict
format_call : bool, optional
If True, the call line is formatted and returned as a string. If not, a
tuple of (name, argspec) is returned.
Returns
-------
call_info : None, str or (str, dict) tuple.
When format_call is True, the whole call information is formattted as a
single string. Otherwise, the object's name and its argspec dict are
returned. If no call information is available, None is returned.
docstring : str or None
The most relevant docstring for calling purposes is returned, if
available. The priority is: call docstring for callable instances, then
constructor docstring for classes, then main object's docstring otherwise
(regular functions).
"""
# Get call definition
argspec = oinfo.get('argspec')
if argspec is None:
call_line = None
else:
# Callable objects will have 'self' as their first argument, prune
# it out if it's there for clarity (since users do *not* pass an
# extra first argument explicitly).
try:
has_self = argspec['args'][0] == 'self'
except (KeyError, IndexError):
pass
else:
if has_self:
argspec['args'] = argspec['args'][1:]
call_line = oinfo['name']+format_argspec(argspec)
# Now get docstring.
# The priority is: call docstring, constructor docstring, main one.
doc = oinfo.get('call_docstring')
if doc is None:
doc = oinfo.get('init_docstring')
if doc is None:
doc = oinfo.get('docstring','')
return call_line, doc
def safe_hasattr(obj, attr):
"""In recent versions of Python, hasattr() only catches AttributeError.
This catches all errors.
"""
try:
getattr(obj, attr)
return True
except:
return False
def find_file(obj):
"""Find the absolute path to the file where an object was defined.
This is essentially a robust wrapper around `inspect.getabsfile`.
Returns None if no file can be found.
Parameters
----------
obj : any Python object
Returns
-------
fname : str
The absolute path to the file where the object was defined.
"""
# get source if obj was decorated with @decorator
if safe_hasattr(obj, '__wrapped__'):
obj = obj.__wrapped__
fname = None
try:
fname = inspect.getabsfile(obj)
except TypeError:
# For an instance, the file that matters is where its class was
# declared.
if hasattr(obj, '__class__'):
try:
fname = inspect.getabsfile(obj.__class__)
except TypeError:
# Can happen for builtins
pass
except:
pass
return cast_unicode(fname)
def find_source_lines(obj):
"""Find the line number in a file where an object was defined.
This is essentially a robust wrapper around `inspect.getsourcelines`.
Returns None if no file can be found.
Parameters
----------
obj : any Python object
Returns
-------
lineno : int
The line number where the object definition starts.
"""
# get source if obj was decorated with @decorator
if safe_hasattr(obj, '__wrapped__'):
obj = obj.__wrapped__
try:
try:
lineno = inspect.getsourcelines(obj)[1]
except TypeError:
# For instances, try the class object like getsource() does
if hasattr(obj, '__class__'):
lineno = inspect.getsourcelines(obj.__class__)[1]
else:
lineno = None
except:
return None
return lineno
class Inspector:
def __init__(self, color_table=InspectColors,
code_color_table=PyColorize.ANSICodeColors,
scheme='NoColor',
str_detail_level=0):
self.color_table = color_table
self.parser = PyColorize.Parser(code_color_table,out='str')
self.format = self.parser.format
self.str_detail_level = str_detail_level
self.set_active_scheme(scheme)
def _getdef(self,obj,oname=''):
"""Return the call signature for any callable object.
If any exception is generated, None is returned instead and the
exception is suppressed."""
try:
hdef = oname + inspect.formatargspec(*getargspec(obj))
return cast_unicode(hdef)
except:
return None
def __head(self,h):
"""Return a header string with proper colors."""
return '%s%s%s' % (self.color_table.active_colors.header,h,
self.color_table.active_colors.normal)
def set_active_scheme(self, scheme):
self.color_table.set_active_scheme(scheme)
self.parser.color_table.set_active_scheme(scheme)
def noinfo(self, msg, oname):
"""Generic message when no information is found."""
print('No %s found' % msg, end=' ')
if oname:
print('for %s' % oname)
else:
print()
def pdef(self, obj, oname=''):
"""Print the call signature for any callable object.
If the object is a class, print the constructor information."""
if not callable(obj):
print('Object is not callable.')
return
header = ''
if inspect.isclass(obj):
header = self.__head('Class constructor information:\n')
obj = obj.__init__
elif (not py3compat.PY3) and type(obj) is types.InstanceType:
obj = obj.__call__
output = self._getdef(obj,oname)
if output is None:
self.noinfo('definition header',oname)
else:
print(header,self.format(output), end=' ', file=io.stdout)
# In Python 3, all classes are new-style, so they all have __init__.
@skip_doctest_py3
def pdoc(self,obj,oname='',formatter = None):
"""Print the docstring for any object.
Optional:
-formatter: a function to run the docstring through for specially
formatted docstrings.
Examples
--------
In [1]: class NoInit:
...: pass
In [2]: class NoDoc:
...: def __init__(self):
...: pass
In [3]: %pdoc NoDoc
No documentation found for NoDoc
In [4]: %pdoc NoInit
No documentation found for NoInit
In [5]: obj = NoInit()
In [6]: %pdoc obj
No documentation found for obj
In [5]: obj2 = NoDoc()
In [6]: %pdoc obj2
No documentation found for obj2
"""
head = self.__head # For convenience
lines = []
ds = getdoc(obj)
if formatter:
ds = formatter(ds)
if ds:
lines.append(head("Class Docstring:"))
lines.append(indent(ds))
if inspect.isclass(obj) and hasattr(obj, '__init__'):
init_ds = getdoc(obj.__init__)
if init_ds is not None:
lines.append(head("Constructor Docstring:"))
lines.append(indent(init_ds))
elif hasattr(obj,'__call__'):
call_ds = getdoc(obj.__call__)
if call_ds:
lines.append(head("Calling Docstring:"))
lines.append(indent(call_ds))
if not lines:
self.noinfo('documentation',oname)
else:
page.page('\n'.join(lines))
def psource(self,obj,oname=''):
"""Print the source code for an object."""
# Flush the source cache because inspect can return out-of-date source
linecache.checkcache()
try:
src = getsource(obj)
except:
self.noinfo('source',oname)
else:
page.page(self.format(src))
def pfile(self, obj, oname=''):
"""Show the whole file where an object was defined."""
lineno = find_source_lines(obj)
if lineno is None:
self.noinfo('file', oname)
return
ofile = find_file(obj)
# run contents of file through pager starting at line where the object
# is defined, as long as the file isn't binary and is actually on the
# filesystem.
if ofile.endswith(('.so', '.dll', '.pyd')):
print('File %r is binary, not printing.' % ofile)
elif not os.path.isfile(ofile):
print('File %r does not exist, not printing.' % ofile)
else:
# Print only text files, not extension binaries. Note that
# getsourcelines returns lineno with 1-offset and page() uses
# 0-offset, so we must adjust.
page.page(self.format(openpy.read_py_file(ofile, skip_encoding_cookie=False)), lineno - 1)
def _format_fields(self, fields, title_width=12):
"""Formats a list of fields for display.
Parameters
----------
fields : list
A list of 2-tuples: (field_title, field_content)
title_width : int
How many characters to pad titles to. Default 12.
"""
out = []
header = self.__head
for title, content in fields:
if len(content.splitlines()) > 1:
title = header(title + ":") + "\n"
else:
title = header((title+":").ljust(title_width))
out.append(cast_unicode(title) + cast_unicode(content))
return "\n".join(out)
# The fields to be displayed by pinfo: (fancy_name, key_in_info_dict)
pinfo_fields1 = [("Type", "type_name"),
]
pinfo_fields2 = [("String Form", "string_form"),
]
pinfo_fields3 = [("Length", "length"),
("File", "file"),
("Definition", "definition"),
]
pinfo_fields_obj = [("Class Docstring", "class_docstring"),
("Constructor Docstring","init_docstring"),
("Call def", "call_def"),
("Call docstring", "call_docstring")]
def pinfo(self,obj,oname='',formatter=None,info=None,detail_level=0):
"""Show detailed information about an object.
Optional arguments:
- oname: name of the variable pointing to the object.
- formatter: special formatter for docstrings (see pdoc)
- info: a structure with some information fields which may have been
precomputed already.
- detail_level: if set to 1, more information is given.
"""
info = self.info(obj, oname=oname, formatter=formatter,
info=info, detail_level=detail_level)
displayfields = []
def add_fields(fields):
for title, key in fields:
field = info[key]
if field is not None:
displayfields.append((title, field.rstrip()))
add_fields(self.pinfo_fields1)
# Base class for old-style instances
if (not py3compat.PY3) and isinstance(obj, types.InstanceType) and info['base_class']:
displayfields.append(("Base Class", info['base_class'].rstrip()))
add_fields(self.pinfo_fields2)
# Namespace
if info['namespace'] != 'Interactive':
displayfields.append(("Namespace", info['namespace'].rstrip()))
add_fields(self.pinfo_fields3)
# Source or docstring, depending on detail level and whether
# source found.
if detail_level > 0 and info['source'] is not None:
displayfields.append(("Source",
self.format(cast_unicode(info['source']))))
elif info['docstring'] is not None:
displayfields.append(("Docstring", info["docstring"]))
# Constructor info for classes
if info['isclass']:
if info['init_definition'] or info['init_docstring']:
displayfields.append(("Constructor information", ""))
if info['init_definition'] is not None:
displayfields.append((" Definition",
info['init_definition'].rstrip()))
if info['init_docstring'] is not None:
displayfields.append((" Docstring",
indent(info['init_docstring'])))
# Info for objects:
else:
add_fields(self.pinfo_fields_obj)
# Finally send to printer/pager:
if displayfields:
page.page(self._format_fields(displayfields))
def info(self, obj, oname='', formatter=None, info=None, detail_level=0):
"""Compute a dict with detailed information about an object.
Optional arguments:
- oname: name of the variable pointing to the object.
- formatter: special formatter for docstrings (see pdoc)
- info: a structure with some information fields which may have been
precomputed already.
- detail_level: if set to 1, more information is given.
"""
obj_type = type(obj)
header = self.__head
if info is None:
ismagic = 0
isalias = 0
ospace = ''
else:
ismagic = info.ismagic
isalias = info.isalias
ospace = info.namespace
# Get docstring, special-casing aliases:
if isalias:
if not callable(obj):
try:
ds = "Alias to the system command:\n %s" % obj[1]
except:
ds = "Alias: " + str(obj)
else:
ds = "Alias to " + str(obj)
if obj.__doc__:
ds += "\nDocstring:\n" + obj.__doc__
else:
ds = getdoc(obj)
if ds is None:
ds = '<no docstring>'
if formatter is not None:
ds = formatter(ds)
# store output in a dict, we initialize it here and fill it as we go
out = dict(name=oname, found=True, isalias=isalias, ismagic=ismagic)
string_max = 200 # max size of strings to show (snipped if longer)
shalf = int((string_max -5)/2)
if ismagic:
obj_type_name = 'Magic function'
elif isalias:
obj_type_name = 'System alias'
else:
obj_type_name = obj_type.__name__
out['type_name'] = obj_type_name
try:
bclass = obj.__class__
out['base_class'] = str(bclass)
except: pass
# String form, but snip if too long in ? form (full in ??)
if detail_level >= self.str_detail_level:
try:
ostr = str(obj)
str_head = 'string_form'
if not detail_level and len(ostr)>string_max:
ostr = ostr[:shalf] + ' <...> ' + ostr[-shalf:]
ostr = ("\n" + " " * len(str_head.expandtabs())).\
join(q.strip() for q in ostr.split("\n"))
out[str_head] = ostr
except:
pass
if ospace:
out['namespace'] = ospace
# Length (for strings and lists)
try:
out['length'] = str(len(obj))
except: pass
# Filename where object was defined
binary_file = False
fname = find_file(obj)
if fname is None:
# if anything goes wrong, we don't want to show source, so it's as
# if the file was binary
binary_file = True
else:
if fname.endswith(('.so', '.dll', '.pyd')):
binary_file = True
elif fname.endswith('<string>'):
fname = 'Dynamically generated function. No source code available.'
out['file'] = fname
# reconstruct the function definition and print it:
defln = self._getdef(obj, oname)
if defln:
out['definition'] = self.format(defln)
# Docstrings only in detail 0 mode, since source contains them (we
# avoid repetitions). If source fails, we add them back, see below.
if ds and detail_level == 0:
out['docstring'] = ds
# Original source code for any callable
if detail_level:
# Flush the source cache because inspect can return out-of-date
# source
linecache.checkcache()
source = None
try:
try:
source = getsource(obj, binary_file)
except TypeError:
if hasattr(obj, '__class__'):
source = getsource(obj.__class__, binary_file)
if source is not None:
out['source'] = source.rstrip()
except Exception:
pass
if ds and source is None:
out['docstring'] = ds
# Constructor docstring for classes
if inspect.isclass(obj):
out['isclass'] = True
# reconstruct the function definition and print it:
try:
obj_init = obj.__init__
except AttributeError:
init_def = init_ds = None
else:
init_def = self._getdef(obj_init,oname)
init_ds = getdoc(obj_init)
# Skip Python's auto-generated docstrings
if init_ds and \
init_ds.startswith('x.__init__(...) initializes'):
init_ds = None
if init_def or init_ds:
if init_def:
out['init_definition'] = self.format(init_def)
if init_ds:
out['init_docstring'] = init_ds
# and class docstring for instances:
else:
# First, check whether the instance docstring is identical to the
# class one, and print it separately if they don't coincide. In
# most cases they will, but it's nice to print all the info for
# objects which use instance-customized docstrings.
if ds:
try:
cls = getattr(obj,'__class__')
except:
class_ds = None
else:
class_ds = getdoc(cls)
# Skip Python's auto-generated docstrings
if class_ds and \
(class_ds.startswith('function(code, globals[,') or \
class_ds.startswith('instancemethod(function, instance,') or \
class_ds.startswith('module(name[,') ):
class_ds = None
if class_ds and ds != class_ds:
out['class_docstring'] = class_ds
# Next, try to show constructor docstrings
try:
init_ds = getdoc(obj.__init__)
# Skip Python's auto-generated docstrings
if init_ds and \
init_ds.startswith('x.__init__(...) initializes'):
init_ds = None
except AttributeError:
init_ds = None
if init_ds:
out['init_docstring'] = init_ds
# Call form docstring for callable instances
if safe_hasattr(obj, '__call__'):
call_def = self._getdef(obj.__call__, oname)
if call_def is not None:
out['call_def'] = self.format(call_def)
call_ds = getdoc(obj.__call__)
# Skip Python's auto-generated docstrings
if call_ds and call_ds.startswith('x.__call__(...) <==> x(...)'):
call_ds = None
if call_ds:
out['call_docstring'] = call_ds
# Compute the object's argspec as a callable. The key is to decide
# whether to pull it from the object itself, from its __init__ or
# from its __call__ method.
if inspect.isclass(obj):
# Old-style classes need not have an __init__
callable_obj = getattr(obj, "__init__", None)
elif callable(obj):
callable_obj = obj
else:
callable_obj = None
if callable_obj:
try:
args, varargs, varkw, defaults = getargspec(callable_obj)
except (TypeError, AttributeError):
# For extensions/builtins we can't retrieve the argspec
pass
else:
out['argspec'] = dict(args=args, varargs=varargs,
varkw=varkw, defaults=defaults)
return object_info(**out)
def psearch(self,pattern,ns_table,ns_search=[],
ignore_case=False,show_all=False):
"""Search namespaces with wildcards for objects.
Arguments:
- pattern: string containing shell-like wildcards to use in namespace
searches and optionally a type specification to narrow the search to
objects of that type.
- ns_table: dict of name->namespaces for search.
Optional arguments:
- ns_search: list of namespace names to include in search.
- ignore_case(False): make the search case-insensitive.
- show_all(False): show all names, including those starting with
underscores.
"""
#print 'ps pattern:<%r>' % pattern # dbg
# defaults
type_pattern = 'all'
filter = ''
cmds = pattern.split()
len_cmds = len(cmds)
if len_cmds == 1:
# Only filter pattern given
filter = cmds[0]
elif len_cmds == 2:
# Both filter and type specified
filter,type_pattern = cmds
else:
raise ValueError('invalid argument string for psearch: <%s>' %
pattern)
# filter search namespaces
for name in ns_search:
if name not in ns_table:
raise ValueError('invalid namespace <%s>. Valid names: %s' %
(name,ns_table.keys()))
#print 'type_pattern:',type_pattern # dbg
search_result, namespaces_seen = set(), set()
for ns_name in ns_search:
ns = ns_table[ns_name]
# Normally, locals and globals are the same, so we just check one.
if id(ns) in namespaces_seen:
continue
namespaces_seen.add(id(ns))
tmp_res = list_namespace(ns, type_pattern, filter,
ignore_case=ignore_case, show_all=show_all)
search_result.update(tmp_res)
page.page('\n'.join(sorted(search_result)))