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# -*- 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) IPython Development Team.
# Distributed under the terms of the Modified BSD License.
from __future__ import print_function
__all__ = ['Inspector','InspectColors']
# stdlib modules
import inspect
import linecache
import os
from textwrap import dedent
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.lib.pretty import pretty
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.dir2 import safe_hasattr
from IPython.utils.path import compress_user
from IPython.utils.text import indent
from IPython.utils.wildcard import list_namespace
from IPython.utils.coloransi import TermColors, ColorScheme, ColorSchemeTable
from IPython.utils.py3compat import cast_unicode, string_types, PY3
from IPython.utils.signatures import signature
# builtin docstrings to ignore
_func_call_docstring = types.FunctionType.__call__.__doc__
_object_init_docstring = object.__init__.__doc__
_builtin_type_docstrings = {
inspect.getdoc(t) for t in (types.ModuleType, types.MethodType,
types.FunctionType, property)
}
_builtin_func_type = type(all)
_builtin_meth_type = type(str.upper) # Bound methods have the same type as builtin functions
#****************************************************************************
# 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.
with stdlib_io.open(ofile, 'rb') as buffer: # 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, string_types):
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, oname=''):
"""Wrapper around inspect.getsource.
This can be modified by other projects to provide customized source
extraction.
Parameters
----------
obj : object
an object whose source code we will attempt to extract
oname : str
(optional) a name under which the object is known
Returns
-------
src : unicode or None
"""
if isinstance(obj, property):
sources = []
for attrname in ['fget', 'fset', 'fdel']:
fn = getattr(obj, attrname)
if fn is not None:
encoding = get_encoding(fn)
oname_prefix = ('%s.' % oname) if oname else ''
sources.append(cast_unicode(
''.join(('# ', oname_prefix, attrname)),
encoding=encoding))
if inspect.isfunction(fn):
sources.append(dedent(getsource(fn)))
else:
# Default str/repr only prints function name,
# pretty.pretty prints module name too.
sources.append(cast_unicode(
'%s%s = %s\n' % (
oname_prefix, attrname, pretty(fn)),
encoding=encoding))
if sources:
return '\n'.join(sources)
else:
return None
else:
# Get source for non-property objects.
obj = _get_wrapped(obj)
try:
src = inspect.getsource(obj)
except TypeError:
# The object itself provided no meaningful source, try looking for
# its class definition instead.
if hasattr(obj, '__class__'):
try:
src = inspect.getsource(obj.__class__)
except TypeError:
return None
encoding = get_encoding(obj)
return cast_unicode(src, encoding=encoding)
def is_simple_callable(obj):
"""True if obj is a function ()"""
return (inspect.isfunction(obj) or inspect.ismethod(obj) or \
isinstance(obj, _builtin_func_type) or isinstance(obj, _builtin_meth_type))
def getargspec(obj):
"""Wrapper around :func:`inspect.getfullargspec` on Python 3, and
:func:inspect.getargspec` on Python 2.
In addition to functions and methods, this can also handle objects with a
``__call__`` attribute.
"""
if safe_hasattr(obj, '__call__') and not is_simple_callable(obj):
obj = obj.__call__
return inspect.getfullargspec(obj) if PY3 else inspect.getargspec(obj)
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 _get_wrapped(obj):
"""Get the original object if wrapped in one or more @decorators"""
while safe_hasattr(obj, '__wrapped__'):
obj = obj.__wrapped__
return obj
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.
"""
obj = _get_wrapped(obj)
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.
"""
obj = _get_wrapped(obj)
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 + str(signature(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("Init docstring:"))
lines.append(indent(init_ds))
elif hasattr(obj,'__call__'):
call_ds = getdoc(obj.__call__)
if call_ds:
lines.append(head("Call 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, oname=oname)
except Exception:
src = None
if src is None:
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=0):
"""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 to longest title.
"""
out = []
header = self.__head
if title_width == 0:
title_width = max(len(title) + 2 for title, _ in fields)
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)
def _format_info(self, obj, oname='', formatter=None, info=None, detail_level=0):
"""Format an info dict as text"""
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()))
if info['isalias']:
add_fields([('Repr', "string_form")])
elif info['ismagic']:
if detail_level > 0 and info['source'] is not None:
add_fields([("Source", "source")])
else:
add_fields([("Docstring", "docstring")])
add_fields([("File", "file"),
])
elif info['isclass'] or is_simple_callable(obj):
# Functions, methods, classes
add_fields([("Signature", "definition"),
("Init signature", "init_definition"),
])
if detail_level > 0 and info['source'] is not None:
add_fields([("Source", "source")])
else:
add_fields([("Docstring", "docstring"),
("Init docstring", "init_docstring"),
])
add_fields([('File', 'file'),
('Type', 'type_name'),
])
else:
# General Python objects
add_fields([("Type", "type_name")])
# 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([("String form", "string_form")])
# Namespace
if info['namespace'] != 'Interactive':
displayfields.append(("Namespace", info['namespace'].rstrip()))
add_fields([("Length", "length"),
("File", "file"),
("Signature", "definition"),
])
# 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"]))
add_fields([("Class docstring", "class_docstring"),
("Init docstring", "init_docstring"),
("Call signature", "call_def"),
("Call docstring", "call_docstring")])
if displayfields:
return self._format_fields(displayfields)
else:
return u''
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.
"""
text = self._format_info(obj, oname, formatter, info, detail_level)
if text:
page.page(text)
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)
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'] = compress_user(fname)
# Original source code for a callable, class or property.
if detail_level:
# Flush the source cache because inspect can return out-of-date
# source
linecache.checkcache()
try:
if isinstance(obj, property) or not binary_file:
src = getsource(obj, oname)
if src is not None:
src = src.rstrip()
out['source'] = src
except Exception:
pass
# Add docstring only if no source is to be shown (avoid repetitions).
if ds and out.get('source', None) 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 == _object_init_docstring:
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:
# reconstruct the function definition and print it:
defln = self._getdef(obj, oname)
if defln:
out['definition'] = self.format(defln)
# 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 in _builtin_type_docstrings:
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 == _object_init_docstring:
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__') and not is_simple_callable(obj):
call_def = self._getdef(obj.__call__, oname)
if call_def:
call_def = self.format(call_def)
# it may never be the case that call def and definition differ,
# but don't include the same signature twice
if call_def != out.get('definition'):
out['call_def'] = call_def
call_ds = getdoc(obj.__call__)
# Skip Python's auto-generated docstrings
if call_ds == _func_call_docstring:
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:
argspec = getargspec(callable_obj)
except (TypeError, AttributeError):
# For extensions/builtins we can't retrieve the argspec
pass
else:
# named tuples' _asdict() method returns an OrderedDict, but we
# we want a normal
out['argspec'] = argspec_dict = dict(argspec._asdict())
# We called this varkw before argspec became a named tuple.
# With getfullargspec it's also called varkw.
if 'varkw' not in argspec_dict:
argspec_dict['varkw'] = argspec_dict.pop('keywords')
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)))
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