python-2.5.2/win32/Lib/inspect.py
changeset 0 ae805ac0140d
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-1:000000000000 0:ae805ac0140d
       
     1 # -*- coding: iso-8859-1 -*-
       
     2 """Get useful information from live Python objects.
       
     3 
       
     4 This module encapsulates the interface provided by the internal special
       
     5 attributes (func_*, co_*, im_*, tb_*, etc.) in a friendlier fashion.
       
     6 It also provides some help for examining source code and class layout.
       
     7 
       
     8 Here are some of the useful functions provided by this module:
       
     9 
       
    10     ismodule(), isclass(), ismethod(), isfunction(), istraceback(),
       
    11         isframe(), iscode(), isbuiltin(), isroutine() - check object types
       
    12     getmembers() - get members of an object that satisfy a given condition
       
    13 
       
    14     getfile(), getsourcefile(), getsource() - find an object's source code
       
    15     getdoc(), getcomments() - get documentation on an object
       
    16     getmodule() - determine the module that an object came from
       
    17     getclasstree() - arrange classes so as to represent their hierarchy
       
    18 
       
    19     getargspec(), getargvalues() - get info about function arguments
       
    20     formatargspec(), formatargvalues() - format an argument spec
       
    21     getouterframes(), getinnerframes() - get info about frames
       
    22     currentframe() - get the current stack frame
       
    23     stack(), trace() - get info about frames on the stack or in a traceback
       
    24 """
       
    25 
       
    26 # This module is in the public domain.  No warranties.
       
    27 
       
    28 __author__ = 'Ka-Ping Yee <ping@lfw.org>'
       
    29 __date__ = '1 Jan 2001'
       
    30 
       
    31 import sys, os, types, string, re, dis, imp, tokenize, linecache
       
    32 from operator import attrgetter
       
    33 
       
    34 # ----------------------------------------------------------- type-checking
       
    35 def ismodule(object):
       
    36     """Return true if the object is a module.
       
    37 
       
    38     Module objects provide these attributes:
       
    39         __doc__         documentation string
       
    40         __file__        filename (missing for built-in modules)"""
       
    41     return isinstance(object, types.ModuleType)
       
    42 
       
    43 def isclass(object):
       
    44     """Return true if the object is a class.
       
    45 
       
    46     Class objects provide these attributes:
       
    47         __doc__         documentation string
       
    48         __module__      name of module in which this class was defined"""
       
    49     return isinstance(object, types.ClassType) or hasattr(object, '__bases__')
       
    50 
       
    51 def ismethod(object):
       
    52     """Return true if the object is an instance method.
       
    53 
       
    54     Instance method objects provide these attributes:
       
    55         __doc__         documentation string
       
    56         __name__        name with which this method was defined
       
    57         im_class        class object in which this method belongs
       
    58         im_func         function object containing implementation of method
       
    59         im_self         instance to which this method is bound, or None"""
       
    60     return isinstance(object, types.MethodType)
       
    61 
       
    62 def ismethoddescriptor(object):
       
    63     """Return true if the object is a method descriptor.
       
    64 
       
    65     But not if ismethod() or isclass() or isfunction() are true.
       
    66 
       
    67     This is new in Python 2.2, and, for example, is true of int.__add__.
       
    68     An object passing this test has a __get__ attribute but not a __set__
       
    69     attribute, but beyond that the set of attributes varies.  __name__ is
       
    70     usually sensible, and __doc__ often is.
       
    71 
       
    72     Methods implemented via descriptors that also pass one of the other
       
    73     tests return false from the ismethoddescriptor() test, simply because
       
    74     the other tests promise more -- you can, e.g., count on having the
       
    75     im_func attribute (etc) when an object passes ismethod()."""
       
    76     return (hasattr(object, "__get__")
       
    77             and not hasattr(object, "__set__") # else it's a data descriptor
       
    78             and not ismethod(object)           # mutual exclusion
       
    79             and not isfunction(object)
       
    80             and not isclass(object))
       
    81 
       
    82 def isdatadescriptor(object):
       
    83     """Return true if the object is a data descriptor.
       
    84 
       
    85     Data descriptors have both a __get__ and a __set__ attribute.  Examples are
       
    86     properties (defined in Python) and getsets and members (defined in C).
       
    87     Typically, data descriptors will also have __name__ and __doc__ attributes
       
    88     (properties, getsets, and members have both of these attributes), but this
       
    89     is not guaranteed."""
       
    90     return (hasattr(object, "__set__") and hasattr(object, "__get__"))
       
    91 
       
    92 if hasattr(types, 'MemberDescriptorType'):
       
    93     # CPython and equivalent
       
    94     def ismemberdescriptor(object):
       
    95         """Return true if the object is a member descriptor.
       
    96 
       
    97         Member descriptors are specialized descriptors defined in extension
       
    98         modules."""
       
    99         return isinstance(object, types.MemberDescriptorType)
       
   100 else:
       
   101     # Other implementations
       
   102     def ismemberdescriptor(object):
       
   103         """Return true if the object is a member descriptor.
       
   104 
       
   105         Member descriptors are specialized descriptors defined in extension
       
   106         modules."""
       
   107         return False
       
   108 
       
   109 if hasattr(types, 'GetSetDescriptorType'):
       
   110     # CPython and equivalent
       
   111     def isgetsetdescriptor(object):
       
   112         """Return true if the object is a getset descriptor.
       
   113 
       
   114         getset descriptors are specialized descriptors defined in extension
       
   115         modules."""
       
   116         return isinstance(object, types.GetSetDescriptorType)
       
   117 else:
       
   118     # Other implementations
       
   119     def isgetsetdescriptor(object):
       
   120         """Return true if the object is a getset descriptor.
       
   121 
       
   122         getset descriptors are specialized descriptors defined in extension
       
   123         modules."""
       
   124         return False
       
   125 
       
   126 def isfunction(object):
       
   127     """Return true if the object is a user-defined function.
       
   128 
       
   129     Function objects provide these attributes:
       
   130         __doc__         documentation string
       
   131         __name__        name with which this function was defined
       
   132         func_code       code object containing compiled function bytecode
       
   133         func_defaults   tuple of any default values for arguments
       
   134         func_doc        (same as __doc__)
       
   135         func_globals    global namespace in which this function was defined
       
   136         func_name       (same as __name__)"""
       
   137     return isinstance(object, types.FunctionType)
       
   138 
       
   139 def istraceback(object):
       
   140     """Return true if the object is a traceback.
       
   141 
       
   142     Traceback objects provide these attributes:
       
   143         tb_frame        frame object at this level
       
   144         tb_lasti        index of last attempted instruction in bytecode
       
   145         tb_lineno       current line number in Python source code
       
   146         tb_next         next inner traceback object (called by this level)"""
       
   147     return isinstance(object, types.TracebackType)
       
   148 
       
   149 def isframe(object):
       
   150     """Return true if the object is a frame object.
       
   151 
       
   152     Frame objects provide these attributes:
       
   153         f_back          next outer frame object (this frame's caller)
       
   154         f_builtins      built-in namespace seen by this frame
       
   155         f_code          code object being executed in this frame
       
   156         f_exc_traceback traceback if raised in this frame, or None
       
   157         f_exc_type      exception type if raised in this frame, or None
       
   158         f_exc_value     exception value if raised in this frame, or None
       
   159         f_globals       global namespace seen by this frame
       
   160         f_lasti         index of last attempted instruction in bytecode
       
   161         f_lineno        current line number in Python source code
       
   162         f_locals        local namespace seen by this frame
       
   163         f_restricted    0 or 1 if frame is in restricted execution mode
       
   164         f_trace         tracing function for this frame, or None"""
       
   165     return isinstance(object, types.FrameType)
       
   166 
       
   167 def iscode(object):
       
   168     """Return true if the object is a code object.
       
   169 
       
   170     Code objects provide these attributes:
       
   171         co_argcount     number of arguments (not including * or ** args)
       
   172         co_code         string of raw compiled bytecode
       
   173         co_consts       tuple of constants used in the bytecode
       
   174         co_filename     name of file in which this code object was created
       
   175         co_firstlineno  number of first line in Python source code
       
   176         co_flags        bitmap: 1=optimized | 2=newlocals | 4=*arg | 8=**arg
       
   177         co_lnotab       encoded mapping of line numbers to bytecode indices
       
   178         co_name         name with which this code object was defined
       
   179         co_names        tuple of names of local variables
       
   180         co_nlocals      number of local variables
       
   181         co_stacksize    virtual machine stack space required
       
   182         co_varnames     tuple of names of arguments and local variables"""
       
   183     return isinstance(object, types.CodeType)
       
   184 
       
   185 def isbuiltin(object):
       
   186     """Return true if the object is a built-in function or method.
       
   187 
       
   188     Built-in functions and methods provide these attributes:
       
   189         __doc__         documentation string
       
   190         __name__        original name of this function or method
       
   191         __self__        instance to which a method is bound, or None"""
       
   192     return isinstance(object, types.BuiltinFunctionType)
       
   193 
       
   194 def isroutine(object):
       
   195     """Return true if the object is any kind of function or method."""
       
   196     return (isbuiltin(object)
       
   197             or isfunction(object)
       
   198             or ismethod(object)
       
   199             or ismethoddescriptor(object))
       
   200 
       
   201 def getmembers(object, predicate=None):
       
   202     """Return all members of an object as (name, value) pairs sorted by name.
       
   203     Optionally, only return members that satisfy a given predicate."""
       
   204     results = []
       
   205     for key in dir(object):
       
   206         value = getattr(object, key)
       
   207         if not predicate or predicate(value):
       
   208             results.append((key, value))
       
   209     results.sort()
       
   210     return results
       
   211 
       
   212 def classify_class_attrs(cls):
       
   213     """Return list of attribute-descriptor tuples.
       
   214 
       
   215     For each name in dir(cls), the return list contains a 4-tuple
       
   216     with these elements:
       
   217 
       
   218         0. The name (a string).
       
   219 
       
   220         1. The kind of attribute this is, one of these strings:
       
   221                'class method'    created via classmethod()
       
   222                'static method'   created via staticmethod()
       
   223                'property'        created via property()
       
   224                'method'          any other flavor of method
       
   225                'data'            not a method
       
   226 
       
   227         2. The class which defined this attribute (a class).
       
   228 
       
   229         3. The object as obtained directly from the defining class's
       
   230            __dict__, not via getattr.  This is especially important for
       
   231            data attributes:  C.data is just a data object, but
       
   232            C.__dict__['data'] may be a data descriptor with additional
       
   233            info, like a __doc__ string.
       
   234     """
       
   235 
       
   236     mro = getmro(cls)
       
   237     names = dir(cls)
       
   238     result = []
       
   239     for name in names:
       
   240         # Get the object associated with the name.
       
   241         # Getting an obj from the __dict__ sometimes reveals more than
       
   242         # using getattr.  Static and class methods are dramatic examples.
       
   243         if name in cls.__dict__:
       
   244             obj = cls.__dict__[name]
       
   245         else:
       
   246             obj = getattr(cls, name)
       
   247 
       
   248         # Figure out where it was defined.
       
   249         homecls = getattr(obj, "__objclass__", None)
       
   250         if homecls is None:
       
   251             # search the dicts.
       
   252             for base in mro:
       
   253                 if name in base.__dict__:
       
   254                     homecls = base
       
   255                     break
       
   256 
       
   257         # Get the object again, in order to get it from the defining
       
   258         # __dict__ instead of via getattr (if possible).
       
   259         if homecls is not None and name in homecls.__dict__:
       
   260             obj = homecls.__dict__[name]
       
   261 
       
   262         # Also get the object via getattr.
       
   263         obj_via_getattr = getattr(cls, name)
       
   264 
       
   265         # Classify the object.
       
   266         if isinstance(obj, staticmethod):
       
   267             kind = "static method"
       
   268         elif isinstance(obj, classmethod):
       
   269             kind = "class method"
       
   270         elif isinstance(obj, property):
       
   271             kind = "property"
       
   272         elif (ismethod(obj_via_getattr) or
       
   273               ismethoddescriptor(obj_via_getattr)):
       
   274             kind = "method"
       
   275         else:
       
   276             kind = "data"
       
   277 
       
   278         result.append((name, kind, homecls, obj))
       
   279 
       
   280     return result
       
   281 
       
   282 # ----------------------------------------------------------- class helpers
       
   283 def _searchbases(cls, accum):
       
   284     # Simulate the "classic class" search order.
       
   285     if cls in accum:
       
   286         return
       
   287     accum.append(cls)
       
   288     for base in cls.__bases__:
       
   289         _searchbases(base, accum)
       
   290 
       
   291 def getmro(cls):
       
   292     "Return tuple of base classes (including cls) in method resolution order."
       
   293     if hasattr(cls, "__mro__"):
       
   294         return cls.__mro__
       
   295     else:
       
   296         result = []
       
   297         _searchbases(cls, result)
       
   298         return tuple(result)
       
   299 
       
   300 # -------------------------------------------------- source code extraction
       
   301 def indentsize(line):
       
   302     """Return the indent size, in spaces, at the start of a line of text."""
       
   303     expline = string.expandtabs(line)
       
   304     return len(expline) - len(string.lstrip(expline))
       
   305 
       
   306 def getdoc(object):
       
   307     """Get the documentation string for an object.
       
   308 
       
   309     All tabs are expanded to spaces.  To clean up docstrings that are
       
   310     indented to line up with blocks of code, any whitespace than can be
       
   311     uniformly removed from the second line onwards is removed."""
       
   312     try:
       
   313         doc = object.__doc__
       
   314     except AttributeError:
       
   315         return None
       
   316     if not isinstance(doc, types.StringTypes):
       
   317         return None
       
   318     try:
       
   319         lines = string.split(string.expandtabs(doc), '\n')
       
   320     except UnicodeError:
       
   321         return None
       
   322     else:
       
   323         # Find minimum indentation of any non-blank lines after first line.
       
   324         margin = sys.maxint
       
   325         for line in lines[1:]:
       
   326             content = len(string.lstrip(line))
       
   327             if content:
       
   328                 indent = len(line) - content
       
   329                 margin = min(margin, indent)
       
   330         # Remove indentation.
       
   331         if lines:
       
   332             lines[0] = lines[0].lstrip()
       
   333         if margin < sys.maxint:
       
   334             for i in range(1, len(lines)): lines[i] = lines[i][margin:]
       
   335         # Remove any trailing or leading blank lines.
       
   336         while lines and not lines[-1]:
       
   337             lines.pop()
       
   338         while lines and not lines[0]:
       
   339             lines.pop(0)
       
   340         return string.join(lines, '\n')
       
   341 
       
   342 def getfile(object):
       
   343     """Work out which source or compiled file an object was defined in."""
       
   344     if ismodule(object):
       
   345         if hasattr(object, '__file__'):
       
   346             return object.__file__
       
   347         raise TypeError('arg is a built-in module')
       
   348     if isclass(object):
       
   349         object = sys.modules.get(object.__module__)
       
   350         if hasattr(object, '__file__'):
       
   351             return object.__file__
       
   352         raise TypeError('arg is a built-in class')
       
   353     if ismethod(object):
       
   354         object = object.im_func
       
   355     if isfunction(object):
       
   356         object = object.func_code
       
   357     if istraceback(object):
       
   358         object = object.tb_frame
       
   359     if isframe(object):
       
   360         object = object.f_code
       
   361     if iscode(object):
       
   362         return object.co_filename
       
   363     raise TypeError('arg is not a module, class, method, '
       
   364                     'function, traceback, frame, or code object')
       
   365 
       
   366 def getmoduleinfo(path):
       
   367     """Get the module name, suffix, mode, and module type for a given file."""
       
   368     filename = os.path.basename(path)
       
   369     suffixes = map(lambda (suffix, mode, mtype):
       
   370                    (-len(suffix), suffix, mode, mtype), imp.get_suffixes())
       
   371     suffixes.sort() # try longest suffixes first, in case they overlap
       
   372     for neglen, suffix, mode, mtype in suffixes:
       
   373         if filename[neglen:] == suffix:
       
   374             return filename[:neglen], suffix, mode, mtype
       
   375 
       
   376 def getmodulename(path):
       
   377     """Return the module name for a given file, or None."""
       
   378     info = getmoduleinfo(path)
       
   379     if info: return info[0]
       
   380 
       
   381 def getsourcefile(object):
       
   382     """Return the Python source file an object was defined in, if it exists."""
       
   383     filename = getfile(object)
       
   384     if string.lower(filename[-4:]) in ('.pyc', '.pyo'):
       
   385         filename = filename[:-4] + '.py'
       
   386     for suffix, mode, kind in imp.get_suffixes():
       
   387         if 'b' in mode and string.lower(filename[-len(suffix):]) == suffix:
       
   388             # Looks like a binary file.  We want to only return a text file.
       
   389             return None
       
   390     if os.path.exists(filename):
       
   391         return filename
       
   392     # only return a non-existent filename if the module has a PEP 302 loader
       
   393     if hasattr(getmodule(object, filename), '__loader__'):
       
   394         return filename
       
   395 
       
   396 def getabsfile(object, _filename=None):
       
   397     """Return an absolute path to the source or compiled file for an object.
       
   398 
       
   399     The idea is for each object to have a unique origin, so this routine
       
   400     normalizes the result as much as possible."""
       
   401     if _filename is None:
       
   402         _filename = getsourcefile(object) or getfile(object)
       
   403     return os.path.normcase(os.path.abspath(_filename))
       
   404 
       
   405 modulesbyfile = {}
       
   406 _filesbymodname = {}
       
   407 
       
   408 def getmodule(object, _filename=None):
       
   409     """Return the module an object was defined in, or None if not found."""
       
   410     if ismodule(object):
       
   411         return object
       
   412     if hasattr(object, '__module__'):
       
   413         return sys.modules.get(object.__module__)
       
   414     # Try the filename to modulename cache
       
   415     if _filename is not None and _filename in modulesbyfile:
       
   416         return sys.modules.get(modulesbyfile[_filename])
       
   417     # Try the cache again with the absolute file name
       
   418     try:
       
   419         file = getabsfile(object, _filename)
       
   420     except TypeError:
       
   421         return None
       
   422     if file in modulesbyfile:
       
   423         return sys.modules.get(modulesbyfile[file])
       
   424     # Update the filename to module name cache and check yet again
       
   425     # Copy sys.modules in order to cope with changes while iterating
       
   426     for modname, module in sys.modules.items():
       
   427         if ismodule(module) and hasattr(module, '__file__'):
       
   428             f = module.__file__
       
   429             if f == _filesbymodname.get(modname, None):
       
   430                 # Have already mapped this module, so skip it
       
   431                 continue
       
   432             _filesbymodname[modname] = f
       
   433             f = getabsfile(module)
       
   434             # Always map to the name the module knows itself by
       
   435             modulesbyfile[f] = modulesbyfile[
       
   436                 os.path.realpath(f)] = module.__name__
       
   437     if file in modulesbyfile:
       
   438         return sys.modules.get(modulesbyfile[file])
       
   439     # Check the main module
       
   440     main = sys.modules['__main__']
       
   441     if not hasattr(object, '__name__'):
       
   442         return None
       
   443     if hasattr(main, object.__name__):
       
   444         mainobject = getattr(main, object.__name__)
       
   445         if mainobject is object:
       
   446             return main
       
   447     # Check builtins
       
   448     builtin = sys.modules['__builtin__']
       
   449     if hasattr(builtin, object.__name__):
       
   450         builtinobject = getattr(builtin, object.__name__)
       
   451         if builtinobject is object:
       
   452             return builtin
       
   453 
       
   454 def findsource(object):
       
   455     """Return the entire source file and starting line number for an object.
       
   456 
       
   457     The argument may be a module, class, method, function, traceback, frame,
       
   458     or code object.  The source code is returned as a list of all the lines
       
   459     in the file and the line number indexes a line in that list.  An IOError
       
   460     is raised if the source code cannot be retrieved."""
       
   461     file = getsourcefile(object) or getfile(object)
       
   462     module = getmodule(object, file)
       
   463     if module:
       
   464         lines = linecache.getlines(file, module.__dict__)
       
   465     else:
       
   466         lines = linecache.getlines(file)
       
   467     if not lines:
       
   468         raise IOError('could not get source code')
       
   469 
       
   470     if ismodule(object):
       
   471         return lines, 0
       
   472 
       
   473     if isclass(object):
       
   474         name = object.__name__
       
   475         pat = re.compile(r'^(\s*)class\s*' + name + r'\b')
       
   476         # make some effort to find the best matching class definition:
       
   477         # use the one with the least indentation, which is the one
       
   478         # that's most probably not inside a function definition.
       
   479         candidates = []
       
   480         for i in range(len(lines)):
       
   481             match = pat.match(lines[i])
       
   482             if match:
       
   483                 # if it's at toplevel, it's already the best one
       
   484                 if lines[i][0] == 'c':
       
   485                     return lines, i
       
   486                 # else add whitespace to candidate list
       
   487                 candidates.append((match.group(1), i))
       
   488         if candidates:
       
   489             # this will sort by whitespace, and by line number,
       
   490             # less whitespace first
       
   491             candidates.sort()
       
   492             return lines, candidates[0][1]
       
   493         else:
       
   494             raise IOError('could not find class definition')
       
   495 
       
   496     if ismethod(object):
       
   497         object = object.im_func
       
   498     if isfunction(object):
       
   499         object = object.func_code
       
   500     if istraceback(object):
       
   501         object = object.tb_frame
       
   502     if isframe(object):
       
   503         object = object.f_code
       
   504     if iscode(object):
       
   505         if not hasattr(object, 'co_firstlineno'):
       
   506             raise IOError('could not find function definition')
       
   507         lnum = object.co_firstlineno - 1
       
   508         pat = re.compile(r'^(\s*def\s)|(.*(?<!\w)lambda(:|\s))|^(\s*@)')
       
   509         while lnum > 0:
       
   510             if pat.match(lines[lnum]): break
       
   511             lnum = lnum - 1
       
   512         return lines, lnum
       
   513     raise IOError('could not find code object')
       
   514 
       
   515 def getcomments(object):
       
   516     """Get lines of comments immediately preceding an object's source code.
       
   517 
       
   518     Returns None when source can't be found.
       
   519     """
       
   520     try:
       
   521         lines, lnum = findsource(object)
       
   522     except (IOError, TypeError):
       
   523         return None
       
   524 
       
   525     if ismodule(object):
       
   526         # Look for a comment block at the top of the file.
       
   527         start = 0
       
   528         if lines and lines[0][:2] == '#!': start = 1
       
   529         while start < len(lines) and string.strip(lines[start]) in ('', '#'):
       
   530             start = start + 1
       
   531         if start < len(lines) and lines[start][:1] == '#':
       
   532             comments = []
       
   533             end = start
       
   534             while end < len(lines) and lines[end][:1] == '#':
       
   535                 comments.append(string.expandtabs(lines[end]))
       
   536                 end = end + 1
       
   537             return string.join(comments, '')
       
   538 
       
   539     # Look for a preceding block of comments at the same indentation.
       
   540     elif lnum > 0:
       
   541         indent = indentsize(lines[lnum])
       
   542         end = lnum - 1
       
   543         if end >= 0 and string.lstrip(lines[end])[:1] == '#' and \
       
   544             indentsize(lines[end]) == indent:
       
   545             comments = [string.lstrip(string.expandtabs(lines[end]))]
       
   546             if end > 0:
       
   547                 end = end - 1
       
   548                 comment = string.lstrip(string.expandtabs(lines[end]))
       
   549                 while comment[:1] == '#' and indentsize(lines[end]) == indent:
       
   550                     comments[:0] = [comment]
       
   551                     end = end - 1
       
   552                     if end < 0: break
       
   553                     comment = string.lstrip(string.expandtabs(lines[end]))
       
   554             while comments and string.strip(comments[0]) == '#':
       
   555                 comments[:1] = []
       
   556             while comments and string.strip(comments[-1]) == '#':
       
   557                 comments[-1:] = []
       
   558             return string.join(comments, '')
       
   559 
       
   560 class EndOfBlock(Exception): pass
       
   561 
       
   562 class BlockFinder:
       
   563     """Provide a tokeneater() method to detect the end of a code block."""
       
   564     def __init__(self):
       
   565         self.indent = 0
       
   566         self.islambda = False
       
   567         self.started = False
       
   568         self.passline = False
       
   569         self.last = 1
       
   570 
       
   571     def tokeneater(self, type, token, (srow, scol), (erow, ecol), line):
       
   572         if not self.started:
       
   573             # look for the first "def", "class" or "lambda"
       
   574             if token in ("def", "class", "lambda"):
       
   575                 if token == "lambda":
       
   576                     self.islambda = True
       
   577                 self.started = True
       
   578             self.passline = True    # skip to the end of the line
       
   579         elif type == tokenize.NEWLINE:
       
   580             self.passline = False   # stop skipping when a NEWLINE is seen
       
   581             self.last = srow
       
   582             if self.islambda:       # lambdas always end at the first NEWLINE
       
   583                 raise EndOfBlock
       
   584         elif self.passline:
       
   585             pass
       
   586         elif type == tokenize.INDENT:
       
   587             self.indent = self.indent + 1
       
   588             self.passline = True
       
   589         elif type == tokenize.DEDENT:
       
   590             self.indent = self.indent - 1
       
   591             # the end of matching indent/dedent pairs end a block
       
   592             # (note that this only works for "def"/"class" blocks,
       
   593             #  not e.g. for "if: else:" or "try: finally:" blocks)
       
   594             if self.indent <= 0:
       
   595                 raise EndOfBlock
       
   596         elif self.indent == 0 and type not in (tokenize.COMMENT, tokenize.NL):
       
   597             # any other token on the same indentation level end the previous
       
   598             # block as well, except the pseudo-tokens COMMENT and NL.
       
   599             raise EndOfBlock
       
   600 
       
   601 def getblock(lines):
       
   602     """Extract the block of code at the top of the given list of lines."""
       
   603     blockfinder = BlockFinder()
       
   604     try:
       
   605         tokenize.tokenize(iter(lines).next, blockfinder.tokeneater)
       
   606     except (EndOfBlock, IndentationError):
       
   607         pass
       
   608     return lines[:blockfinder.last]
       
   609 
       
   610 def getsourcelines(object):
       
   611     """Return a list of source lines and starting line number for an object.
       
   612 
       
   613     The argument may be a module, class, method, function, traceback, frame,
       
   614     or code object.  The source code is returned as a list of the lines
       
   615     corresponding to the object and the line number indicates where in the
       
   616     original source file the first line of code was found.  An IOError is
       
   617     raised if the source code cannot be retrieved."""
       
   618     lines, lnum = findsource(object)
       
   619 
       
   620     if ismodule(object): return lines, 0
       
   621     else: return getblock(lines[lnum:]), lnum + 1
       
   622 
       
   623 def getsource(object):
       
   624     """Return the text of the source code for an object.
       
   625 
       
   626     The argument may be a module, class, method, function, traceback, frame,
       
   627     or code object.  The source code is returned as a single string.  An
       
   628     IOError is raised if the source code cannot be retrieved."""
       
   629     lines, lnum = getsourcelines(object)
       
   630     return string.join(lines, '')
       
   631 
       
   632 # --------------------------------------------------- class tree extraction
       
   633 def walktree(classes, children, parent):
       
   634     """Recursive helper function for getclasstree()."""
       
   635     results = []
       
   636     classes.sort(key=attrgetter('__module__', '__name__'))
       
   637     for c in classes:
       
   638         results.append((c, c.__bases__))
       
   639         if c in children:
       
   640             results.append(walktree(children[c], children, c))
       
   641     return results
       
   642 
       
   643 def getclasstree(classes, unique=0):
       
   644     """Arrange the given list of classes into a hierarchy of nested lists.
       
   645 
       
   646     Where a nested list appears, it contains classes derived from the class
       
   647     whose entry immediately precedes the list.  Each entry is a 2-tuple
       
   648     containing a class and a tuple of its base classes.  If the 'unique'
       
   649     argument is true, exactly one entry appears in the returned structure
       
   650     for each class in the given list.  Otherwise, classes using multiple
       
   651     inheritance and their descendants will appear multiple times."""
       
   652     children = {}
       
   653     roots = []
       
   654     for c in classes:
       
   655         if c.__bases__:
       
   656             for parent in c.__bases__:
       
   657                 if not parent in children:
       
   658                     children[parent] = []
       
   659                 children[parent].append(c)
       
   660                 if unique and parent in classes: break
       
   661         elif c not in roots:
       
   662             roots.append(c)
       
   663     for parent in children:
       
   664         if parent not in classes:
       
   665             roots.append(parent)
       
   666     return walktree(roots, children, None)
       
   667 
       
   668 # ------------------------------------------------ argument list extraction
       
   669 # These constants are from Python's compile.h.
       
   670 CO_OPTIMIZED, CO_NEWLOCALS, CO_VARARGS, CO_VARKEYWORDS = 1, 2, 4, 8
       
   671 
       
   672 def getargs(co):
       
   673     """Get information about the arguments accepted by a code object.
       
   674 
       
   675     Three things are returned: (args, varargs, varkw), where 'args' is
       
   676     a list of argument names (possibly containing nested lists), and
       
   677     'varargs' and 'varkw' are the names of the * and ** arguments or None."""
       
   678 
       
   679     if not iscode(co):
       
   680         raise TypeError('arg is not a code object')
       
   681 
       
   682     nargs = co.co_argcount
       
   683     names = co.co_varnames
       
   684     args = list(names[:nargs])
       
   685     step = 0
       
   686 
       
   687     # The following acrobatics are for anonymous (tuple) arguments.
       
   688     for i in range(nargs):
       
   689         if args[i][:1] in ('', '.'):
       
   690             stack, remain, count = [], [], []
       
   691             while step < len(co.co_code):
       
   692                 op = ord(co.co_code[step])
       
   693                 step = step + 1
       
   694                 if op >= dis.HAVE_ARGUMENT:
       
   695                     opname = dis.opname[op]
       
   696                     value = ord(co.co_code[step]) + ord(co.co_code[step+1])*256
       
   697                     step = step + 2
       
   698                     if opname in ('UNPACK_TUPLE', 'UNPACK_SEQUENCE'):
       
   699                         remain.append(value)
       
   700                         count.append(value)
       
   701                     elif opname == 'STORE_FAST':
       
   702                         stack.append(names[value])
       
   703 
       
   704                         # Special case for sublists of length 1: def foo((bar))
       
   705                         # doesn't generate the UNPACK_TUPLE bytecode, so if
       
   706                         # `remain` is empty here, we have such a sublist.
       
   707                         if not remain:
       
   708                             stack[0] = [stack[0]]
       
   709                             break
       
   710                         else:
       
   711                             remain[-1] = remain[-1] - 1
       
   712                             while remain[-1] == 0:
       
   713                                 remain.pop()
       
   714                                 size = count.pop()
       
   715                                 stack[-size:] = [stack[-size:]]
       
   716                                 if not remain: break
       
   717                                 remain[-1] = remain[-1] - 1
       
   718                             if not remain: break
       
   719             args[i] = stack[0]
       
   720 
       
   721     varargs = None
       
   722     if co.co_flags & CO_VARARGS:
       
   723         varargs = co.co_varnames[nargs]
       
   724         nargs = nargs + 1
       
   725     varkw = None
       
   726     if co.co_flags & CO_VARKEYWORDS:
       
   727         varkw = co.co_varnames[nargs]
       
   728     return args, varargs, varkw
       
   729 
       
   730 def getargspec(func):
       
   731     """Get the names and default values of a function's arguments.
       
   732 
       
   733     A tuple of four things is returned: (args, varargs, varkw, defaults).
       
   734     'args' is a list of the argument names (it may contain nested lists).
       
   735     'varargs' and 'varkw' are the names of the * and ** arguments or None.
       
   736     'defaults' is an n-tuple of the default values of the last n arguments.
       
   737     """
       
   738 
       
   739     if ismethod(func):
       
   740         func = func.im_func
       
   741     if not isfunction(func):
       
   742         raise TypeError('arg is not a Python function')
       
   743     args, varargs, varkw = getargs(func.func_code)
       
   744     return args, varargs, varkw, func.func_defaults
       
   745 
       
   746 def getargvalues(frame):
       
   747     """Get information about arguments passed into a particular frame.
       
   748 
       
   749     A tuple of four things is returned: (args, varargs, varkw, locals).
       
   750     'args' is a list of the argument names (it may contain nested lists).
       
   751     'varargs' and 'varkw' are the names of the * and ** arguments or None.
       
   752     'locals' is the locals dictionary of the given frame."""
       
   753     args, varargs, varkw = getargs(frame.f_code)
       
   754     return args, varargs, varkw, frame.f_locals
       
   755 
       
   756 def joinseq(seq):
       
   757     if len(seq) == 1:
       
   758         return '(' + seq[0] + ',)'
       
   759     else:
       
   760         return '(' + string.join(seq, ', ') + ')'
       
   761 
       
   762 def strseq(object, convert, join=joinseq):
       
   763     """Recursively walk a sequence, stringifying each element."""
       
   764     if type(object) in (list, tuple):
       
   765         return join(map(lambda o, c=convert, j=join: strseq(o, c, j), object))
       
   766     else:
       
   767         return convert(object)
       
   768 
       
   769 def formatargspec(args, varargs=None, varkw=None, defaults=None,
       
   770                   formatarg=str,
       
   771                   formatvarargs=lambda name: '*' + name,
       
   772                   formatvarkw=lambda name: '**' + name,
       
   773                   formatvalue=lambda value: '=' + repr(value),
       
   774                   join=joinseq):
       
   775     """Format an argument spec from the 4 values returned by getargspec.
       
   776 
       
   777     The first four arguments are (args, varargs, varkw, defaults).  The
       
   778     other four arguments are the corresponding optional formatting functions
       
   779     that are called to turn names and values into strings.  The ninth
       
   780     argument is an optional function to format the sequence of arguments."""
       
   781     specs = []
       
   782     if defaults:
       
   783         firstdefault = len(args) - len(defaults)
       
   784     for i in range(len(args)):
       
   785         spec = strseq(args[i], formatarg, join)
       
   786         if defaults and i >= firstdefault:
       
   787             spec = spec + formatvalue(defaults[i - firstdefault])
       
   788         specs.append(spec)
       
   789     if varargs is not None:
       
   790         specs.append(formatvarargs(varargs))
       
   791     if varkw is not None:
       
   792         specs.append(formatvarkw(varkw))
       
   793     return '(' + string.join(specs, ', ') + ')'
       
   794 
       
   795 def formatargvalues(args, varargs, varkw, locals,
       
   796                     formatarg=str,
       
   797                     formatvarargs=lambda name: '*' + name,
       
   798                     formatvarkw=lambda name: '**' + name,
       
   799                     formatvalue=lambda value: '=' + repr(value),
       
   800                     join=joinseq):
       
   801     """Format an argument spec from the 4 values returned by getargvalues.
       
   802 
       
   803     The first four arguments are (args, varargs, varkw, locals).  The
       
   804     next four arguments are the corresponding optional formatting functions
       
   805     that are called to turn names and values into strings.  The ninth
       
   806     argument is an optional function to format the sequence of arguments."""
       
   807     def convert(name, locals=locals,
       
   808                 formatarg=formatarg, formatvalue=formatvalue):
       
   809         return formatarg(name) + formatvalue(locals[name])
       
   810     specs = []
       
   811     for i in range(len(args)):
       
   812         specs.append(strseq(args[i], convert, join))
       
   813     if varargs:
       
   814         specs.append(formatvarargs(varargs) + formatvalue(locals[varargs]))
       
   815     if varkw:
       
   816         specs.append(formatvarkw(varkw) + formatvalue(locals[varkw]))
       
   817     return '(' + string.join(specs, ', ') + ')'
       
   818 
       
   819 # -------------------------------------------------- stack frame extraction
       
   820 def getframeinfo(frame, context=1):
       
   821     """Get information about a frame or traceback object.
       
   822 
       
   823     A tuple of five things is returned: the filename, the line number of
       
   824     the current line, the function name, a list of lines of context from
       
   825     the source code, and the index of the current line within that list.
       
   826     The optional second argument specifies the number of lines of context
       
   827     to return, which are centered around the current line."""
       
   828     if istraceback(frame):
       
   829         lineno = frame.tb_lineno
       
   830         frame = frame.tb_frame
       
   831     else:
       
   832         lineno = frame.f_lineno
       
   833     if not isframe(frame):
       
   834         raise TypeError('arg is not a frame or traceback object')
       
   835 
       
   836     filename = getsourcefile(frame) or getfile(frame)
       
   837     if context > 0:
       
   838         start = lineno - 1 - context//2
       
   839         try:
       
   840             lines, lnum = findsource(frame)
       
   841         except IOError:
       
   842             lines = index = None
       
   843         else:
       
   844             start = max(start, 1)
       
   845             start = max(0, min(start, len(lines) - context))
       
   846             lines = lines[start:start+context]
       
   847             index = lineno - 1 - start
       
   848     else:
       
   849         lines = index = None
       
   850 
       
   851     return (filename, lineno, frame.f_code.co_name, lines, index)
       
   852 
       
   853 def getlineno(frame):
       
   854     """Get the line number from a frame object, allowing for optimization."""
       
   855     # FrameType.f_lineno is now a descriptor that grovels co_lnotab
       
   856     return frame.f_lineno
       
   857 
       
   858 def getouterframes(frame, context=1):
       
   859     """Get a list of records for a frame and all higher (calling) frames.
       
   860 
       
   861     Each record contains a frame object, filename, line number, function
       
   862     name, a list of lines of context, and index within the context."""
       
   863     framelist = []
       
   864     while frame:
       
   865         framelist.append((frame,) + getframeinfo(frame, context))
       
   866         frame = frame.f_back
       
   867     return framelist
       
   868 
       
   869 def getinnerframes(tb, context=1):
       
   870     """Get a list of records for a traceback's frame and all lower frames.
       
   871 
       
   872     Each record contains a frame object, filename, line number, function
       
   873     name, a list of lines of context, and index within the context."""
       
   874     framelist = []
       
   875     while tb:
       
   876         framelist.append((tb.tb_frame,) + getframeinfo(tb, context))
       
   877         tb = tb.tb_next
       
   878     return framelist
       
   879 
       
   880 currentframe = sys._getframe
       
   881 
       
   882 def stack(context=1):
       
   883     """Return a list of records for the stack above the caller's frame."""
       
   884     return getouterframes(sys._getframe(1), context)
       
   885 
       
   886 def trace(context=1):
       
   887     """Return a list of records for the stack below the current exception."""
       
   888     return getinnerframes(sys.exc_info()[2], context)