|
|
# encoding: utf-8
|
|
|
"""A fancy version of Python's builtin :func:`dir` function.
|
|
|
"""
|
|
|
|
|
|
# Copyright (c) IPython Development Team.
|
|
|
# Distributed under the terms of the Modified BSD License.
|
|
|
|
|
|
import inspect
|
|
|
import types
|
|
|
|
|
|
|
|
|
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 dir2(obj):
|
|
|
"""dir2(obj) -> list of strings
|
|
|
|
|
|
Extended version of the Python builtin dir(), which does a few extra
|
|
|
checks.
|
|
|
|
|
|
This version is guaranteed to return only a list of true strings, whereas
|
|
|
dir() returns anything that objects inject into themselves, even if they
|
|
|
are later not really valid for attribute access (many extension libraries
|
|
|
have such bugs).
|
|
|
"""
|
|
|
|
|
|
# Start building the attribute list via dir(), and then complete it
|
|
|
# with a few extra special-purpose calls.
|
|
|
|
|
|
try:
|
|
|
words = set(dir(obj))
|
|
|
except Exception:
|
|
|
# TypeError: dir(obj) does not return a list
|
|
|
words = set()
|
|
|
|
|
|
if safe_hasattr(obj, '__class__'):
|
|
|
words |= set(dir(obj.__class__))
|
|
|
|
|
|
# filter out non-string attributes which may be stuffed by dir() calls
|
|
|
# and poor coding in third-party modules
|
|
|
|
|
|
words = [w for w in words if isinstance(w, str)]
|
|
|
return sorted(words)
|
|
|
|
|
|
|
|
|
def get_real_method(obj, name):
|
|
|
"""Like getattr, but with a few extra sanity checks:
|
|
|
|
|
|
- If obj is a class, ignore everything except class methods
|
|
|
- Check if obj is a proxy that claims to have all attributes
|
|
|
- Catch attribute access failing with any exception
|
|
|
- Check that the attribute is a callable object
|
|
|
|
|
|
Returns the method or None.
|
|
|
"""
|
|
|
try:
|
|
|
canary = getattr(obj, '_ipython_canary_method_should_not_exist_', None)
|
|
|
except Exception:
|
|
|
return None
|
|
|
|
|
|
if canary is not None:
|
|
|
# It claimed to have an attribute it should never have
|
|
|
return None
|
|
|
|
|
|
try:
|
|
|
m = getattr(obj, name, None)
|
|
|
except Exception:
|
|
|
return None
|
|
|
|
|
|
if inspect.isclass(obj) and not isinstance(m, types.MethodType):
|
|
|
return None
|
|
|
|
|
|
if callable(m):
|
|
|
return m
|
|
|
|
|
|
return None
|
|
|
|
