Application: gvSIG desktop » gvSIG scripting

"""Get useful information from live Python objects.

This module encapsulates the interface provided by the internal special

attributes (func_*, co_*, im_*, tb_*, etc.) in a friendlier fashion.

It also provides some help for examining source code and class layout.

Here are some of the useful functions provided by this module:

    ismodule(), isclass(), ismethod(), isfunction(), istraceback(),

        isframe(), iscode(), isbuiltin(), isroutine() - check object types

    getmembers() - get members of an object that satisfy a given condition

    getfile(), getsourcefile(), getsource() - find an object's source code

    getdoc(), getcomments() - get documentation on an object

    getmodule() - determine the module that an object came from

    getclasstree() - arrange classes so as to represent their hierarchy

    getargspec(), getargvalues() - get info about function arguments

    formatargspec(), formatargvalues() - format an argument spec

    getouterframes(), getinnerframes() - get info about frames

    currentframe() - get the current stack frame

    stack(), trace() - get info about frames on the stack or in a traceback

"""

# This module is in the public domain.  No warranties.

__author__ = 'Ka-Ping Yee <ping@lfw.org>'

__date__ = '1 Jan 2001'

import sys, os, types, string, re, dis, imp, tokenize

# ----------------------------------------------------------- type-checking

def ismodule(object):

    """Return true if the object is a module.

    Module objects provide these attributes:

        __doc__         documentation string

        __file__        filename (missing for built-in modules)"""

    return isinstance(object, types.ModuleType)

def isclass(object):

    """Return true if the object is a class.

    Class objects provide these attributes:

        __doc__         documentation string

        __module__      name of module in which this class was defined"""

    return isinstance(object, types.ClassType) or hasattr(object, '__bases__')

def ismethod(object):

    """Return true if the object is an instance method.

    Instance method objects provide these attributes:

        __doc__         documentation string

        __name__        name with which this method was defined

        im_class        class object in which this method belongs

        im_func         function object containing implementation of method

        im_self         instance to which this method is bound, or None"""

    return isinstance(object, types.MethodType)

def ismethoddescriptor(object):

    """Return true if the object is a method descriptor.

    But not if ismethod() or isclass() or isfunction() are true.

    This is new in Python 2.2, and, for example, is true of int.__add__.

    An object passing this test has a __get__ attribute but not a __set__

    attribute, but beyond that the set of attributes varies.  __name__ is

    usually sensible, and __doc__ often is.

    Methods implemented via descriptors that also pass one of the other

    tests return false from the ismethoddescriptor() test, simply because

    the other tests promise more -- you can, e.g., count on having the

    im_func attribute (etc) when an object passes ismethod()."""

    return (hasattr(object, "__get__")

            and not hasattr(object, "__set__") # else it's a data descriptor

            and not ismethod(object)           # mutual exclusion

            and not isfunction(object)

            and not isclass(object))

def isfunction(object):

    """Return true if the object is a user-defined function.

    Function objects provide these attributes:

        __doc__         documentation string

        __name__        name with which this function was defined

        func_code       code object containing compiled function bytecode

        func_defaults   tuple of any default values for arguments

        func_doc        (same as __doc__)

        func_globals    global namespace in which this function was defined

        func_name       (same as __name__)"""

    return isinstance(object, types.FunctionType)

def istraceback(object):

    """Return true if the object is a traceback.

    Traceback objects provide these attributes:

        tb_frame        frame object at this level

        tb_lasti        index of last attempted instruction in bytecode

        tb_lineno       current line number in Python source code

        tb_next         next inner traceback object (called by this level)"""

    return isinstance(object, types.TracebackType)

def isframe(object):

    """Return true if the object is a frame object.

    Frame objects provide these attributes:

        f_back          next outer frame object (this frame's caller)

        f_builtins      built-in namespace seen by this frame

        f_code          code object being executed in this frame

        f_exc_traceback traceback if raised in this frame, or None

        f_exc_type      exception type if raised in this frame, or None

        f_exc_value     exception value if raised in this frame, or None

        f_globals       global namespace seen by this frame

        f_lasti         index of last attempted instruction in bytecode

        f_lineno        current line number in Python source code

        f_locals        local namespace seen by this frame

        f_restricted    0 or 1 if frame is in restricted execution mode

        f_trace         tracing function for this frame, or None"""

    return isinstance(object, types.FrameType)

def iscode(object):

    """Return true if the object is a code object.

    Code objects provide these attributes:

        co_argcount     number of arguments (not including * or ** args)

        co_code         string of raw compiled bytecode

        co_consts       tuple of constants used in the bytecode

        co_filename     name of file in which this code object was created

        co_firstlineno  number of first line in Python source code

        co_flags        bitmap: 1=optimized | 2=newlocals | 4=*arg | 8=**arg

        co_lnotab       encoded mapping of line numbers to bytecode indices

        co_name         name with which this code object was defined

        co_names        tuple of names of local variables

        co_nlocals      number of local variables

        co_stacksize    virtual machine stack space required

        co_varnames     tuple of names of arguments and local variables"""

    return isinstance(object, types.CodeType)

def isbuiltin(object):

    """Return true if the object is a built-in function or method.

    Built-in functions and methods provide these attributes:

        __doc__         documentation string

        __name__        original name of this function or method

        __self__        instance to which a method is bound, or None"""

    return isinstance(object, types.BuiltinFunctionType)

def isroutine(object):

    """Return true if the object is any kind of function or method."""

    return (isbuiltin(object)

            or isfunction(object)

            or ismethod(object)

            or ismethoddescriptor(object))

def getmembers(object, predicate=None):

    """Return all members of an object as (name, value) pairs sorted by name.

    Optionally, only return members that satisfy a given predicate."""

    results = []

    for key in dir(object):

        value = getattr(object, key)

        if not predicate or predicate(value):

            results.append((key, value))

    results.sort()

    return results

def classify_class_attrs(cls):

    """Return list of attribute-descriptor tuples.

    For each name in dir(cls), the return list contains a 4-tuple

    with these elements:

        0. The name (a string).

        1. The kind of attribute this is, one of these strings:

               'class method'    created via classmethod()

               'static method'   created via staticmethod()

               'property'        created via property()

               'method'          any other flavor of method

               'data'            not a method

        2. The class which defined this attribute (a class).

        3. The object as obtained directly from the defining class's

           __dict__, not via getattr.  This is especially important for

           data attributes:  C.data is just a data object, but

           C.__dict__['data'] may be a data descriptor with additional

           info, like a __doc__ string.

    """

    mro = getmro(cls)

    names = dir(cls)

    result = []

    for name in names:

        # Get the object associated with the name.

        # Getting an obj from the __dict__ sometimes reveals more than

        # using getattr.  Static and class methods are dramatic examples.

        if name in cls.__dict__:

            obj = cls.__dict__[name]

        else:

            obj = getattr(cls, name)

        # Figure out where it was defined.

        homecls = getattr(obj, "__objclass__", None)

        if homecls is None:

            # search the dicts.

            for base in mro:

                if name in base.__dict__:

                    homecls = base

                    break

        # Get the object again, in order to get it from the defining

        # __dict__ instead of via getattr (if possible).

        if homecls is not None and name in homecls.__dict__:

            obj = homecls.__dict__[name]

        # Also get the object via getattr.

        obj_via_getattr = getattr(cls, name)

        # Classify the object.

        if isinstance(obj, staticmethod):

            kind = "static method"

        elif isinstance(obj, classmethod):

            kind = "class method"

        elif isinstance(obj, property):

            kind = "property"

        elif (ismethod(obj_via_getattr) or

              ismethoddescriptor(obj_via_getattr)):

            kind = "method"

        else:

            kind = "data"

        result.append((name, kind, homecls, obj))

    return result

# ----------------------------------------------------------- class helpers

def _searchbases(cls, accum):

    # Simulate the "classic class" search order.

    if cls in accum:

        return

    accum.append(cls)

    for base in cls.__bases__:

        _searchbases(base, accum)

def getmro(cls):

    "Return tuple of base classes (including cls) in method resolution order."

    if hasattr(cls, "__mro__"):

        return cls.__mro__

    else:

        result = []

        _searchbases(cls, result)

        return tuple(result)

# -------------------------------------------------- source code extraction

def indentsize(line):

    """Return the indent size, in spaces, at the start of a line of text."""

    expline = string.expandtabs(line)

    return len(expline) - len(string.lstrip(expline))

def getdoc(object):

    """Get the documentation string for an object.

    All tabs are expanded to spaces.  To clean up docstrings that are

    indented to line up with blocks of code, any whitespace than can be

    uniformly removed from the second line onwards is removed."""

    try:

        doc = object.__doc__

    except AttributeError:

        return None

    # Jython doesn't like this syntax

    # if not isinstance(doc, (str, unicode)):

    # in Jython UnicodeType == StringType

    if not isinstance(doc, types.StringType):

        return None

    try:

        lines = string.split(string.expandtabs(doc), '\n')

    except UnicodeError:

        return None

    else:

        margin = None

        for line in lines[1:]:

            content = len(string.lstrip(line))

            if not content: continue

            indent = len(line) - content

            if margin is None: margin = indent

            else: margin = min(margin, indent)

        if margin is not None:

            for i in range(1, len(lines)): lines[i] = lines[i][margin:]

        return string.join(lines, '\n')

def getfile(object):

    """Work out which source or compiled file an object was defined in."""

    if ismodule(object):

        if hasattr(object, '__file__'):

            return object.__file__

        raise TypeError, 'arg is a built-in module'

    if isclass(object):

        object = sys.modules.get(object.__module__)

        if hasattr(object, '__file__'):

            return object.__file__

        raise TypeError, 'arg is a built-in class'

    if ismethod(object):

        object = object.im_func

    if isfunction(object):

        object = object.func_code

    if istraceback(object):

        object = object.tb_frame

    if isframe(object):

        object = object.f_code

    if iscode(object):

        return object.co_filename

    raise TypeError, 'arg is not a module, class, method, ' \

                     'function, traceback, frame, or code object'

def getmoduleinfo(path):

    """Get the module name, suffix, mode, and module type for a given file."""

    filename = os.path.basename(path)

    suffixes = map(lambda (suffix, mode, mtype):

                   (-len(suffix), suffix, mode, mtype), imp.get_suffixes())

    suffixes.sort() # try longest suffixes first, in case they overlap

    for neglen, suffix, mode, mtype in suffixes:

        if filename[neglen:] == suffix:

            return filename[:neglen], suffix, mode, mtype

def getmodulename(path):

    """Return the module name for a given file, or None."""

    info = getmoduleinfo(path)

    if info: return info[0]

def getsourcefile(object):

    """Return the Python source file an object was defined in, if it exists."""

    filename = getfile(object)

    if string.lower(filename[-4:]) in ['.pyc', '.pyo']:

        filename = filename[:-4] + '.py'

    for suffix, mode, kind in imp.get_suffixes():

        if 'b' in mode and string.lower(filename[-len(suffix):]) == suffix:

            # Looks like a binary file.  We want to only return a text file.

            return None

    if os.path.exists(filename):

        return filename

def getabsfile(object):

    """Return an absolute path to the source or compiled file for an object.

    The idea is for each object to have a unique origin, so this routine

    normalizes the result as much as possible."""

    return os.path.normcase(

        os.path.abspath(getsourcefile(object) or getfile(object)))

modulesbyfile = {}

def getmodule(object):

    """Return the module an object was defined in, or None if not found."""

    if ismodule(object):

        return object

    if isclass(object):

        return sys.modules.get(object.__module__)

    try:

        file = getabsfile(object)

    except TypeError:

        return None

    if modulesbyfile.has_key(file):

        return sys.modules[modulesbyfile[file]]

    for module in sys.modules.values():

        if hasattr(module, '__file__'):

            modulesbyfile[getabsfile(module)] = module.__name__

    if modulesbyfile.has_key(file):

        return sys.modules[modulesbyfile[file]]

    main = sys.modules['__main__']

    if hasattr(main, object.__name__):

        mainobject = getattr(main, object.__name__)

        if mainobject is object:

            return main

    builtin = sys.modules['__builtin__']

    if hasattr(builtin, object.__name__):

        builtinobject = getattr(builtin, object.__name__)

        if builtinobject is object:

            return builtin

def findsource(object):

    """Return the entire source file and starting line number for an object.

    The argument may be a module, class, method, function, traceback, frame,

    or code object.  The source code is returned as a list of all the lines

    in the file and the line number indexes a line in that list.  An IOError

    is raised if the source code cannot be retrieved."""

    try:

        file = open(getsourcefile(object))

    except (TypeError, IOError):

        raise IOError, 'could not get source code'

    lines = file.readlines()

    file.close()

    if ismodule(object):

        return lines, 0

    if isclass(object):

        name = object.__name__

        pat = re.compile(r'^\s*class\s*' + name + r'\b')

        for i in range(len(lines)):

            if pat.match(lines[i]): return lines, i

        else: raise IOError, 'could not find class definition'

    if ismethod(object):

        object = object.im_func

    if isfunction(object):

        object = object.func_code

    if istraceback(object):

        object = object.tb_frame

    if isframe(object):

        object = object.f_code

    if iscode(object):

        if not hasattr(object, 'co_firstlineno'):

            raise IOError, 'could not find function definition'

        lnum = object.co_firstlineno - 1

        pat = re.compile(r'^\s*def\s')

        while lnum > 0:

            if pat.match(lines[lnum]): break

            lnum = lnum - 1

        return lines, lnum

    raise IOError, 'could not find code object'

def getcomments(object):

    """Get lines of comments immediately preceding an object's source code."""

    try: lines, lnum = findsource(object)

    except IOError: return None

    if ismodule(object):

        # Look for a comment block at the top of the file.

        start = 0

        if lines and lines[0][:2] == '#!': start = 1

        while start < len(lines) and string.strip(lines[start]) in ['', '#']:

            start = start + 1

        if start < len(lines) and lines[start][:1] == '#':

            comments = []

            end = start

            while end < len(lines) and lines[end][:1] == '#':

                comments.append(string.expandtabs(lines[end]))

                end = end + 1

            return string.join(comments, '')

    # Look for a preceding block of comments at the same indentation.

    elif lnum > 0:

        indent = indentsize(lines[lnum])

        end = lnum - 1

        if end >= 0 and string.lstrip(lines[end])[:1] == '#' and \

            indentsize(lines[end]) == indent:

            comments = [string.lstrip(string.expandtabs(lines[end]))]

            if end > 0:

                end = end - 1

                comment = string.lstrip(string.expandtabs(lines[end]))

                while comment[:1] == '#' and indentsize(lines[end]) == indent:

                    comments[:0] = [comment]

                    end = end - 1

                    if end < 0: break

                    comment = string.lstrip(string.expandtabs(lines[end]))

            while comments and string.strip(comments[0]) == '#':

                comments[:1] = []

            while comments and string.strip(comments[-1]) == '#':

                comments[-1:] = []

            return string.join(comments, '')

class ListReader:

    """Provide a readline() method to return lines from a list of strings."""

    def __init__(self, lines):

        self.lines = lines

        self.index = 0

    def readline(self):

        i = self.index

        if i < len(self.lines):

            self.index = i + 1

            return self.lines[i]

        else: return ''

class EndOfBlock(Exception): pass

class BlockFinder:

    """Provide a tokeneater() method to detect the end of a code block."""

    def __init__(self):

        self.indent = 0

        self.started = 0

        self.last = 0

    def tokeneater(self, type, token, (srow, scol), (erow, ecol), line):

        if not self.started:

            if type == tokenize.NAME: self.started = 1

        elif type == tokenize.NEWLINE:

            self.last = srow

        elif type == tokenize.INDENT:

            self.indent = self.indent + 1

        elif type == tokenize.DEDENT:

            self.indent = self.indent - 1

            if self.indent == 0: raise EndOfBlock, self.last

def getblock(lines):

    """Extract the block of code at the top of the given list of lines."""

    try:

        tokenize.tokenize(ListReader(lines).readline, BlockFinder().tokeneater)

    except EndOfBlock, eob:

        return lines[:eob.args[0]]

def getsourcelines(object):

    """Return a list of source lines and starting line number for an object.

    The argument may be a module, class, method, function, traceback, frame,

    or code object.  The source code is returned as a list of the lines

    corresponding to the object and the line number indicates where in the

    original source file the first line of code was found.  An IOError is

    raised if the source code cannot be retrieved."""

    lines, lnum = findsource(object)

    if ismodule(object): return lines, 0

    else: return getblock(lines[lnum:]), lnum + 1

def getsource(object):

    """Return the text of the source code for an object.

    The argument may be a module, class, method, function, traceback, frame,

    or code object.  The source code is returned as a single string.  An

    IOError is raised if the source code cannot be retrieved."""

    lines, lnum = getsourcelines(object)

    return string.join(lines, '')

# --------------------------------------------------- class tree extraction

def walktree(classes, children, parent):

    """Recursive helper function for getclasstree()."""

    results = []

    classes.sort(lambda a, b: cmp(a.__name__, b.__name__))

    for c in classes:

        results.append((c, c.__bases__))

        if children.has_key(c):

            results.append(walktree(children[c], children, c))

    return results

def getclasstree(classes, unique=0):

    """Arrange the given list of classes into a hierarchy of nested lists.

    Where a nested list appears, it contains classes derived from the class

    whose entry immediately precedes the list.  Each entry is a 2-tuple

    containing a class and a tuple of its base classes.  If the 'unique'

    argument is true, exactly one entry appears in the returned structure

    for each class in the given list.  Otherwise, classes using multiple

    inheritance and their descendants will appear multiple times."""

    children = {}

    roots = []

    for c in classes:

        if c.__bases__:

            for parent in c.__bases__:

                if not children.has_key(parent):

                    children[parent] = []

                children[parent].append(c)

                if unique and parent in classes: break

        elif c not in roots:

            roots.append(c)

    for parent in children.keys():

        if parent not in classes:

            roots.append(parent)

    return walktree(roots, children, None)

# ------------------------------------------------ argument list extraction

# These constants are from Python's compile.h.

CO_OPTIMIZED, CO_NEWLOCALS, CO_VARARGS, CO_VARKEYWORDS = 1, 2, 4, 8

def getargs(co):

    """Get information about the arguments accepted by a code object.

    Three things are returned: (args, varargs, varkw), where 'args' is

    a list of argument names (possibly containing nested lists), and

    'varargs' and 'varkw' are the names of the * and ** arguments or None."""

    if not iscode(co): raise TypeError, 'arg is not a code object'

##     #jython doesn't have co_code

##     code = co.co_code

    nargs = co.co_argcount

    names = co.co_varnames

    args = list(names[:nargs])

    step = 0

## We don't have co_code, so skip this for now

##    

##     # The following acrobatics are for anonymous (tuple) arguments.

##     for i in range(nargs):

##         if args[i][:1] in ['', '.']:

##             stack, remain, count = [], [], []

##             while step < len(code):

##                 op = ord(code[step])

##                 step = step + 1

##                 if op >= dis.HAVE_ARGUMENT:

##                     opname = dis.opname[op]

##                     value = ord(code[step]) + ord(code[step+1])*256

##                     step = step + 2

##                     if opname in ['UNPACK_TUPLE', 'UNPACK_SEQUENCE']:

##                         remain.append(value)

##                         count.append(value)

##                     elif opname == 'STORE_FAST':

##                         stack.append(names[value])

##                         remain[-1] = remain[-1] - 1

##                         while remain[-1] == 0:

##                             remain.pop()

##                             size = count.pop()

##                             stack[-size:] = [stack[-size:]]

##                             if not remain: break

##                             remain[-1] = remain[-1] - 1

##                         if not remain: break

##             args[i] = stack[0]

    varargs = None

    if co.co_flags & CO_VARARGS:

        varargs = co.co_varnames[nargs]

        nargs = nargs + 1

    varkw = None

    if co.co_flags & CO_VARKEYWORDS:

        varkw = co.co_varnames[nargs]

    return args, varargs, varkw

def getargspec(func):

    """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."""

    if not isfunction(func): raise TypeError, 'arg is not a Python function'

    args, varargs, varkw = getargs(func.func_code)

    return args, varargs, varkw, func.func_defaults

def getargvalues(frame):

    """Get information about arguments passed into a particular frame.

    A tuple of four things is returned: (args, varargs, varkw, locals).

    '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.

    'locals' is the locals dictionary of the given frame."""

    args, varargs, varkw = getargs(frame.f_code)

    return args, varargs, varkw, frame.f_locals

def joinseq(seq):

    if len(seq) == 1:

        return '(' + seq[0] + ',)'

    else:

        return '(' + string.join(seq, ', ') + ')'

def strseq(object, convert, join=joinseq):

    """Recursively walk a sequence, stringifying each element."""

    if type(object) in [types.ListType, types.TupleType]:

        return join(map(lambda o, c=convert, j=join: strseq(o, c, j), object))

    else:

        return convert(object)

def formatargspec(args, varargs=None, varkw=None, defaults=None,

                  formatarg=str,

                  formatvarargs=lambda name: '*' + name,

                  formatvarkw=lambda name: '**' + name,

                  formatvalue=lambda value: '=' + repr(value),

                  join=joinseq):

    """Format an argument spec from the 4 values returned by getargspec.

    The first four arguments are (args, varargs, varkw, defaults).  The

    other four arguments are the corresponding optional formatting functions

    that are called to turn names and values into strings.  The ninth

    argument is an optional function to format the sequence of arguments."""

    specs = []

    if defaults:

        firstdefault = len(args) - len(defaults)

    for i in range(len(args)):

        spec = strseq(args[i], formatarg, join)

        if defaults and i >= firstdefault:

            spec = spec + formatvalue(defaults[i - firstdefault])

        specs.append(spec)

    if varargs:

        specs.append(formatvarargs(varargs))

    if varkw:

        specs.append(formatvarkw(varkw))

    return '(' + string.join(specs, ', ') + ')'

def formatargvalues(args, varargs, varkw, locals,

                    formatarg=str,

                    formatvarargs=lambda name: '*' + name,

                    formatvarkw=lambda name: '**' + name,

                    formatvalue=lambda value: '=' + repr(value),

                    join=joinseq):

    """Format an argument spec from the 4 values returned by getargvalues.

    The first four arguments are (args, varargs, varkw, locals).  The

    next four arguments are the corresponding optional formatting functions

    that are called to turn names and values into strings.  The ninth

    argument is an optional function to format the sequence of arguments."""

    def convert(name, locals=locals,

                formatarg=formatarg, formatvalue=formatvalue):

        return formatarg(name) + formatvalue(locals[name])

    specs = []

    for i in range(len(args)):

        specs.append(strseq(args[i], convert, join))

    if varargs:

        specs.append(formatvarargs(varargs) + formatvalue(locals[varargs]))

    if varkw:

        specs.append(formatvarkw(varkw) + formatvalue(locals[varkw]))

    return '(' + string.join(specs, ', ') + ')'

# -------------------------------------------------- stack frame extraction

def getframeinfo(frame, context=1):

    """Get information about a frame or traceback object.

    A tuple of five things is returned: the filename, the line number of

    the current line, the function name, a list of lines of context from

    the source code, and the index of the current line within that list.

    The optional second argument specifies the number of lines of context

    to return, which are centered around the current line."""

    if istraceback(frame):

        frame = frame.tb_frame

    if not isframe(frame):

        raise TypeError, 'arg is not a frame or traceback object'

    filename = getsourcefile(frame)

    lineno = getlineno(frame)

    if context > 0:

##         # Jython 2.1 can't handle //

##         start = lineno - 1 - context//2

        start = lineno - 1 - context/2

        try:

            lines, lnum = findsource(frame)

        except IOError:

            lines = index = None

        else:

            start = max(start, 1)

            start = min(start, len(lines) - context)

            lines = lines[start:start+context]

            index = lineno - 1 - start

    else:

        lines = index = None

    return (filename, lineno, frame.f_code.co_name, lines, index)

def getlineno(frame):

    """Get the line number from a frame object, allowing for optimization."""

    # Written by Marc-Andr? Lemburg; revised by Jim Hugunin and Fredrik Lundh.

    lineno = frame.f_lineno

    code = frame.f_code

    if hasattr(code, 'co_lnotab'):

        table = code.co_lnotab

        lineno = code.co_firstlineno

        addr = 0

        for i in range(0, len(table), 2):

            addr = addr + ord(table[i])

            if addr > frame.f_lasti: break

            lineno = lineno + ord(table[i+1])

    return lineno

def getouterframes(frame, context=1):

    """Get a list of records for a frame and all higher (calling) frames.

    Each record contains a frame object, filename, line number, function

    name, a list of lines of context, and index within the context."""

    framelist = []

    while frame:

        framelist.append((frame,) + getframeinfo(frame, context))

        frame = frame.f_back

    return framelist

def getinnerframes(tb, context=1):

    """Get a list of records for a traceback's frame and all lower frames.

    Each record contains a frame object, filename, line number, function

    name, a list of lines of context, and index within the context."""

    framelist = []

    while tb:

        framelist.append((tb.tb_frame,) + getframeinfo(tb, context))

        tb = tb.tb_next

    return framelist

def currentframe():

    """Return the frame object for the caller's stack frame."""

    try:

        raise 'catch me'

    except:

        return sys.exc_traceback.tb_frame.f_back

if hasattr(sys, '_getframe'): currentframe = sys._getframe

def stack(context=1):

    """Return a list of records for the stack above the caller's frame."""

    return getouterframes(currentframe().f_back, context)

def trace(context=1):

    """Return a list of records for the stack below the current exception."""

    return getinnerframes(sys.exc_traceback, context)