Merge pull request #4382 from jtratner/safer-hasattr-in-dir2

Use safe_hasattr in dir2

IPython/core/oinspect.py

@@ -1,882 +1,873 b''
 # -*- 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 <[e-mail]>
 #
 #  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.dir2 import safe_hasattr
 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)))

IPython/utils/dir2.py

@@ -1,73 +1,83 b''
 # encoding: utf-8
 """A fancy version of Python's builtin :func:`dir` function.
 """
 
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2008-2011  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
 #-----------------------------------------------------------------------------
-
 #-----------------------------------------------------------------------------
 # Code
 #-----------------------------------------------------------------------------
 
+
+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 get_class_members(cls):
     ret = dir(cls)
-    if hasattr(cls, '__bases__'):
+    if safe_hasattr(cls, '__bases__'):
         try:
             bases = cls.__bases__
         except AttributeError:
             # `obj` lied to hasattr (e.g. Pyro), ignore
             pass
         else:
             for base in bases:
                 ret.extend(get_class_members(base))
     return ret
 
 
 def dir2(obj):
     """dir2(obj) -> list of strings
 
     Extended version of the Python builtin dir(), which does a few extra
     checks, and supports common objects with unusual internals that confuse
     dir(), such as Traits and PyCrust.
 
     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.
 
     words = set(dir(obj))
 
-    if hasattr(obj, '__class__'):
+    if safe_hasattr(obj, '__class__'):
         #words.add('__class__')
         words |= set(get_class_members(obj.__class__))
 
 
     # for objects with Enthought's traits, add trait_names() list
     # for PyCrust-style, add _getAttributeNames() magic method list
     for attr in ('trait_names', '_getAttributeNames'):
-        if hasattr(obj, attr):
-            try:
-                func = getattr(obj, attr)
-                if callable(func):
-                    words |= set(func())
-            except:
-                # TypeError: obj is class not instance
-                pass
+        try:
+            func = getattr(obj, attr)
+            if callable(func):
+                words |= set(func())
+        except:
+            # TypeError: obj is class not instance
+            pass
 
     # 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, basestring)]
     return sorted(words)

IPython/utils/tests/test_dir2.py

@@ -1,52 +1,80 b''
 import nose.tools as nt
 from IPython.utils.dir2 import dir2
 
 
 class Base(object):
     x = 1
     z = 23
 
 
 def test_base():
     res = dir2(Base())
     assert ('x' in res)
     assert ('z' in res)
     assert ('y' not in res)
     assert ('__class__' in res)
     nt.assert_equal(res.count('x'), 1)
     nt.assert_equal(res.count('__class__'), 1)
 
 def test_SubClass():
 
     class SubClass(Base):
         y = 2
 
     res = dir2(SubClass())
     assert ('y' in res)
     nt.assert_equal(res.count('y'), 1)
     nt.assert_equal(res.count('x'), 1)
 
 
 def test_SubClass_with_trait_names_method():
 
     class SubClass(Base):
         y = 2
         def trait_names(self):
             return ['t', 'umbrella']
 
     res = dir2(SubClass())
     assert('trait_names' in res)
     assert('umbrella' in res)
     nt.assert_equal(res[-6:], ['t', 'trait_names','umbrella', 'x','y','z'])
     nt.assert_equal(res.count('t'), 1)
 
 
 def test_SubClass_with_trait_names_attr():
     # usecase: trait_names is used in a class describing psychological classification
 
     class SubClass(Base):
         y = 2
         trait_names = 44
 
     res = dir2(SubClass())
     assert('trait_names' in res)
+
+
+def test_misbehaving_object_without_trait_names():
+    # dir2 shouldn't raise even when objects are dumb and raise
+    # something other than AttribteErrors on bad getattr.
+
+    class BadTraitNames(object):
+        @property
+        def trait_names(self):
+            raise KeyboardInterrupt("This should be caught")
+
+        def some_method(self):
+            pass
+
+    class MisbehavingGetattr(object):
+        def __getattr__(self):
+            raise KeyError("I should be caught")
+
+        def some_method(self):
+            pass
+
+    class SillierWithDir(MisbehavingGetattr):
+        def __dir__(self):
+            return ['some_method']
+
+    for bad_klass in (BadTraitNames, MisbehavingGetattr, SillierWithDir):
+        res = dir2(bad_klass())
+        assert('some_method' in res)