environment/lib/python2.7/site-packages/IPython/core/ultratb.py
def structured_traceback(self, etype, evalue, etb, tb_offset=None,
                             context=5):
        """Return a nice text document describing the traceback."""

        tb_offset = self.tb_offset if tb_offset is None else tb_offset

        # some locals
        try:
            etype = etype.__name__
        except AttributeError:
            pass
        Colors        = self.Colors   # just a shorthand + quicker name lookup
        ColorsNormal  = Colors.Normal  # used a lot
        col_scheme    = self.color_scheme_table.active_scheme_name
        indent        = ' '*INDENT_SIZE
        em_normal     = '%s\n%s%s' % (Colors.valEm, indent,ColorsNormal)
        undefined     = '%sundefined%s' % (Colors.em, ColorsNormal)
        exc = '%s%s%s' % (Colors.excName,etype,ColorsNormal)

        # some internal-use functions
        def text_repr(value):
            """Hopefully pretty robust repr equivalent."""
            # this is pretty horrible but should always return *something*
            try:
                return pydoc.text.repr(value)
            except KeyboardInterrupt:
                raise
            except:
                try:
                    return repr(value)
                except KeyboardInterrupt:
                    raise
                except:
                    try:
                        # all still in an except block so we catch
                        # getattr raising
                        name = getattr(value, '__name__', None)
                        if name:
                            # ick, recursion
                            return text_repr(name)
                        klass = getattr(value, '__class__', None)
                        if klass:
                            return '%s instance' % text_repr(klass)
                    except KeyboardInterrupt:
                        raise
                    except:
                        return 'UNRECOVERABLE REPR FAILURE'
        def eqrepr(value, repr=text_repr): return '=%s' % repr(value)
        def nullrepr(value, repr=text_repr): return ''

        # meat of the code begins
        try:
            etype = etype.__name__
        except AttributeError:
            pass

        if self.long_header:
            # Header with the exception type, python version, and date
            pyver = 'Python ' + sys.version.split()[0] + ': ' + sys.executable
            date = time.ctime(time.time())

            head = '%s%s%s\n%s%s%s\n%s' % (Colors.topline, '-'*75, ColorsNormal,
                                           exc, ' '*(75-len(str(etype))-len(pyver)),
                                           pyver, date.rjust(75) )
            head += "\nA problem occured executing Python code.  Here is the sequence of function"\
                    "\ncalls leading up to the error, with the most recent (innermost) call last."
        else:
            # Simplified header
            head = '%s%s%s\n%s%s' % (Colors.topline, '-'*75, ColorsNormal,exc,
                                     'Traceback (most recent call last)'.\
                                                  rjust(75 - len(str(etype)) ) )
        frames = []
        # Flush cache before calling inspect.  This helps alleviate some of the
        # problems with python 2.3's inspect.py.
        ##self.check_cache()
        # Drop topmost frames if requested
        try:
            # Try the default getinnerframes and Alex's: Alex's fixes some
            # problems, but it generates empty tracebacks for console errors
            # (5 blanks lines) where none should be returned.
            #records = inspect.getinnerframes(etb, context)[tb_offset:]
            #print 'python records:', records # dbg
            records = _fixed_getinnerframes(etb, context, tb_offset)
            #print 'alex   records:', records # dbg
        except:

            # FIXME: I've been getting many crash reports from python 2.3
            # users, traceable to inspect.py.  If I can find a small test-case
            # to reproduce this, I should either write a better workaround or
            # file a bug report against inspect (if that's the real problem).
            # So far, I haven't been able to find an isolated example to
            # reproduce the problem.
            inspect_error()
            traceback.print_exc(file=self.ostream)
            info('\nUnfortunately, your original traceback can not be constructed.\n')
            return ''

        # build some color string templates outside these nested loops
        tpl_link       = '%s%%s%s' % (Colors.filenameEm,ColorsNormal)
        tpl_call       = 'in %s%%s%s%%s%s' % (Colors.vName, Colors.valEm,
                                              ColorsNormal)
        tpl_call_fail  = 'in %s%%s%s(***failed resolving arguments***)%s' % \
                         (Colors.vName, Colors.valEm, ColorsNormal)
        tpl_local_var  = '%s%%s%s' % (Colors.vName, ColorsNormal)
        tpl_global_var = '%sglobal%s %s%%s%s' % (Colors.em, ColorsNormal,
                                                 Colors.vName, ColorsNormal)
        tpl_name_val   = '%%s %s= %%s%s' % (Colors.valEm, ColorsNormal)
        tpl_line       = '%s%%s%s %%s' % (Colors.lineno, ColorsNormal)
        tpl_line_em    = '%s%%s%s %%s%s' % (Colors.linenoEm,Colors.line,
                                            ColorsNormal)

        # now, loop over all records printing context and info
        abspath = os.path.abspath
        for frame, file, lnum, func, lines, index in records:
            #print '*** record:',file,lnum,func,lines,index  # dbg

            if not file:
                file = '?'
            elif not(file.startswith("<") and file.endswith(">")):
                # Guess that filenames like <string> aren't real filenames, so
                # don't call abspath on them.                    
                try:
                    file = abspath(file)
                except OSError:
                    # Not sure if this can still happen: abspath now works with
                    # file names like <string>
                    pass

            link = tpl_link % file
            args, varargs, varkw, locals = inspect.getargvalues(frame)

            if func == '?':
                call = ''
            else:
                # Decide whether to include variable details or not
                var_repr = self.include_vars and eqrepr or nullrepr
                try:
                    call = tpl_call % (func,inspect.formatargvalues(args,
                                                varargs, varkw,
                                                locals,formatvalue=var_repr))
                except KeyError:
                    # This happens in situations like errors inside generator
                    # expressions, where local variables are listed in the
                    # line, but can't be extracted from the frame.  I'm not
                    # 100% sure this isn't actually a bug in inspect itself,
                    # but since there's no info for us to compute with, the
                    # best we can do is report the failure and move on.  Here
                    # we must *not* call any traceback construction again,
                    # because that would mess up use of %debug later on.  So we
                    # simply report the failure and move on.  The only
                    # limitation will be that this frame won't have locals
                    # listed in the call signature.  Quite subtle problem...
                    # I can't think of a good way to validate this in a unit
                    # test, but running a script consisting of:
                    #  dict( (k,v.strip()) for (k,v) in range(10) )
                    # will illustrate the error, if this exception catch is
                    # disabled.
                    call = tpl_call_fail % func
            
            # Don't attempt to tokenize binary files.
            if file.endswith(('.so', '.pyd', '.dll')):
                frames.append('%s %s\n' % (link,call))
                continue
            elif file.endswith(('.pyc','.pyo')):
                # Look up the corresponding source file.
                file = pyfile.source_from_cache(file)

            def linereader(file=file, lnum=[lnum], getline=linecache.getline):
                line = getline(file, lnum[0])
                lnum[0] += 1
                return line

            # Build the list of names on this line of code where the exception
            # occurred.
            try:
                names = []
                name_cont = False
                
                for token_type, token, start, end, line in generate_tokens(linereader):
                    # build composite names
                    if token_type == tokenize.NAME and token not in keyword.kwlist:
                        if name_cont:
                            # Continuation of a dotted name
                            try:
                                names[-1].append(token)
                            except IndexError:
                                names.append([token])
                            name_cont = False
                        else:
                            # Regular new names.  We append everything, the caller
                            # will be responsible for pruning the list later.  It's
                            # very tricky to try to prune as we go, b/c composite
                            # names can fool us.  The pruning at the end is easy
                            # to do (or the caller can print a list with repeated
                            # names if so desired.
                            names.append([token])
                    elif token == '.':
                        name_cont = True
                    elif token_type == tokenize.NEWLINE:
                        break
                        
            except (IndexError, UnicodeDecodeError):
                # signals exit of tokenizer
                pass
            except tokenize.TokenError,msg:
                _m = ("An unexpected error occurred while tokenizing input\n"
                      "The following traceback may be corrupted or invalid\n"
                      "The error message is: %s\n" % msg)
                error(_m)

            # Join composite names (e.g. "dict.fromkeys")
            names = ['.'.join(n) for n in names]
            # prune names list of duplicates, but keep the right order
            unique_names = uniq_stable(names)

            # Start loop over vars
            lvals = []
            if self.include_vars:
                for name_full in unique_names:
                    name_base = name_full.split('.',1)[0]
                    if name_base in frame.f_code.co_varnames:
                        if locals.has_key(name_base):
                            try:
                                value = repr(eval(name_full,locals))
                            except:
                                value = undefined
                        else:
                            value = undefined
                        name = tpl_local_var % name_full
                    else:
                        if frame.f_globals.has_key(name_base):
                            try:
                                value = repr(eval(name_full,frame.f_globals))
                            except:
                                value = undefined
                        else:
                            value = undefined
                        name = tpl_global_var % name_full
                    lvals.append(tpl_name_val % (name,value))
            if lvals:
                lvals = '%s%s' % (indent,em_normal.join(lvals))
            else:
                lvals = ''

            level = '%s %s\n' % (link,call)

            if index is None:
                frames.append(level)
            else:
                frames.append('%s%s' % (level,''.join(
                    _format_traceback_lines(lnum,index,lines,Colors,lvals,
                                            col_scheme))))

        # Get (safely) a string form of the exception info
        try:
            etype_str,evalue_str = map(str,(etype,evalue))
        except:
            # User exception is improperly defined.
            etype,evalue = str,sys.exc_info()[:2]
            etype_str,evalue_str = map(str,(etype,evalue))
        # ... and format it
        exception = ['%s%s%s: %s' % (Colors.excName, etype_str,
                                     ColorsNormal, evalue_str)]
        if (not py3compat.PY3) and type(evalue) is types.InstanceType:
            try:
                names = [w for w in dir(evalue) if isinstance(w, basestring)]
            except:
                # Every now and then, an object with funny inernals blows up
                # when dir() is called on it.  We do the best we can to report
                # the problem and continue
                _m = '%sException reporting error (object with broken dir())%s:'
                exception.append(_m % (Colors.excName,ColorsNormal))
                etype_str,evalue_str = map(str,sys.exc_info()[:2])
                exception.append('%s%s%s: %s' % (Colors.excName,etype_str,
                                     ColorsNormal, evalue_str))
                names = []
            for name in names:
                value = text_repr(getattr(evalue, name))
                exception.append('\n%s%s = %s' % (indent, name, value))

        # vds: >>
        if records:
             filepath, lnum = records[-1][1:3]
             #print "file:", str(file), "linenb", str(lnum) # dbg
             filepath = os.path.abspath(filepath)
             ipinst = ipapi.get()
             if ipinst is not None:
                 ipinst.hooks.synchronize_with_editor(filepath, lnum, 0)
        # vds: <<

        # return all our info assembled as a single string
        # return '%s\n\n%s\n%s' % (head,'\n'.join(frames),''.join(exception[0]) )
        return [head] + frames + [''.join(exception[0])]
def structured_traceback(self, etype, evalue, etb, tb_offset=None,
                             context=5):
        """Return a nice text document describing the traceback."""

        tb_offset = self.tb_offset if tb_offset is None else tb_offset

        # some locals
        try:
            etype = etype.__name__
        except AttributeError:
            pass
        Colors        = self.Colors   # just a shorthand + quicker name lookup
        ColorsNormal  = Colors.Normal  # used a lot
        col_scheme    = self.color_scheme_table.active_scheme_name
        indent        = ' '*INDENT_SIZE
        em_normal     = '%s\n%s%s' % (Colors.valEm, indent,ColorsNormal)
        undefined     = '%sundefined%s' % (Colors.em, ColorsNormal)
        exc = '%s%s%s' % (Colors.excName,etype,ColorsNormal)

        # some internal-use functions
        def text_repr(value):
            """Hopefully pretty robust repr equivalent."""
            # this is pretty horrible but should always return *something*
            try:
                return pydoc.text.repr(value)
            except KeyboardInterrupt:
                raise
            except:
                try:
                    return repr(value)
                except KeyboardInterrupt:
                    raise
                except:
                    try:
                        # all still in an except block so we catch
                        # getattr raising
                        name = getattr(value, '__name__', None)
                        if name:
                            # ick, recursion
                            return text_repr(name)
                        klass = getattr(value, '__class__', None)
                        if klass:
                            return '%s instance' % text_repr(klass)
                    except KeyboardInterrupt:
                        raise
                    except:
                        return 'UNRECOVERABLE REPR FAILURE'
        def eqrepr(value, repr=text_repr): return '=%s' % repr(value)
        def nullrepr(value, repr=text_repr): return ''

        # meat of the code begins
        try:
            etype = etype.__name__
        except AttributeError:
            pass

        if self.long_header:
            # Header with the exception type, python version, and date
            pyver = 'Python ' + sys.version.split()[0] + ': ' + sys.executable
            date = time.ctime(time.time())

            head = '%s%s%s\n%s%s%s\n%s' % (Colors.topline, '-'*75, ColorsNormal,
                                           exc, ' '*(75-len(str(etype))-len(pyver)),
                                           pyver, date.rjust(75) )
            head += "\nA problem occured executing Python code.  Here is the sequence of function"\
                    "\ncalls leading up to the error, with the most recent (innermost) call last."
        else:
            # Simplified header
            head = '%s%s%s\n%s%s' % (Colors.topline, '-'*75, ColorsNormal,exc,
                                     'Traceback (most recent call last)'.\
                                                  rjust(75 - len(str(etype)) ) )
        frames = []
        # Flush cache before calling inspect.  This helps alleviate some of the
        # problems with python 2.3's inspect.py.
        ##self.check_cache()
        # Drop topmost frames if requested
        try:
            # Try the default getinnerframes and Alex's: Alex's fixes some
            # problems, but it generates empty tracebacks for console errors
            # (5 blanks lines) where none should be returned.
            #records = inspect.getinnerframes(etb, context)[tb_offset:]
            #print 'python records:', records # dbg
            records = _fixed_getinnerframes(etb, context, tb_offset)
            #print 'alex   records:', records # dbg
        except:

            # FIXME: I've been getting many crash reports from python 2.3
            # users, traceable to inspect.py.  If I can find a small test-case
            # to reproduce this, I should either write a better workaround or
            # file a bug report against inspect (if that's the real problem).
            # So far, I haven't been able to find an isolated example to
            # reproduce the problem.
            inspect_error()
            traceback.print_exc(file=self.ostream)
            info('\nUnfortunately, your original traceback can not be constructed.\n')
            return ''

        # build some color string templates outside these nested loops
        tpl_link       = '%s%%s%s' % (Colors.filenameEm,ColorsNormal)
        tpl_call       = 'in %s%%s%s%%s%s' % (Colors.vName, Colors.valEm,
                                              ColorsNormal)
        tpl_call_fail  = 'in %s%%s%s(***failed resolving arguments***)%s' % \
                         (Colors.vName, Colors.valEm, ColorsNormal)
        tpl_local_var  = '%s%%s%s' % (Colors.vName, ColorsNormal)
        tpl_global_var = '%sglobal%s %s%%s%s' % (Colors.em, ColorsNormal,
                                                 Colors.vName, ColorsNormal)
        tpl_name_val   = '%%s %s= %%s%s' % (Colors.valEm, ColorsNormal)
        tpl_line       = '%s%%s%s %%s' % (Colors.lineno, ColorsNormal)
        tpl_line_em    = '%s%%s%s %%s%s' % (Colors.linenoEm,Colors.line,
                                            ColorsNormal)

        # now, loop over all records printing context and info
        abspath = os.path.abspath
        for frame, file, lnum, func, lines, index in records:
            #print '*** record:',file,lnum,func,lines,index  # dbg

            if not file:
                file = '?'
            elif not(file.startswith("<") and file.endswith(">")):
                # Guess that filenames like <string> aren't real filenames, so
                # don't call abspath on them.                    
                try:
                    file = abspath(file)
                except OSError:
                    # Not sure if this can still happen: abspath now works with
                    # file names like <string>
                    pass

            link = tpl_link % file
            args, varargs, varkw, locals = inspect.getargvalues(frame)

            if func == '?':
                call = ''
            else:
                # Decide whether to include variable details or not
                var_repr = self.include_vars and eqrepr or nullrepr
                try:
                    call = tpl_call % (func,inspect.formatargvalues(args,
                                                varargs, varkw,
                                                locals,formatvalue=var_repr))
                except KeyError:
                    # This happens in situations like errors inside generator
                    # expressions, where local variables are listed in the
                    # line, but can't be extracted from the frame.  I'm not
                    # 100% sure this isn't actually a bug in inspect itself,
                    # but since there's no info for us to compute with, the
                    # best we can do is report the failure and move on.  Here
                    # we must *not* call any traceback construction again,
                    # because that would mess up use of %debug later on.  So we
                    # simply report the failure and move on.  The only
                    # limitation will be that this frame won't have locals
                    # listed in the call signature.  Quite subtle problem...
                    # I can't think of a good way to validate this in a unit
                    # test, but running a script consisting of:
                    #  dict( (k,v.strip()) for (k,v) in range(10) )
                    # will illustrate the error, if this exception catch is
                    # disabled.
                    call = tpl_call_fail % func
            
            # Don't attempt to tokenize binary files.
            if file.endswith(('.so', '.pyd', '.dll')):
                frames.append('%s %s\n' % (link,call))
                continue
            elif file.endswith(('.pyc','.pyo')):
                # Look up the corresponding source file.
                file = pyfile.source_from_cache(file)

            def linereader(file=file, lnum=[lnum], getline=linecache.getline):
                line = getline(file, lnum[0])
                lnum[0] += 1
                return line

            # Build the list of names on this line of code where the exception
            # occurred.
            try:
                names = []
                name_cont = False
                
                for token_type, token, start, end, line in generate_tokens(linereader):
                    # build composite names
                    if token_type == tokenize.NAME and token not in keyword.kwlist:
                        if name_cont:
                            # Continuation of a dotted name
                            try:
                                names[-1].append(token)
                            except IndexError:
                                names.append([token])
                            name_cont = False
                        else:
                            # Regular new names.  We append everything, the caller
                            # will be responsible for pruning the list later.  It's
                            # very tricky to try to prune as we go, b/c composite
                            # names can fool us.  The pruning at the end is easy
                            # to do (or the caller can print a list with repeated
                            # names if so desired.
                            names.append([token])
                    elif token == '.':
                        name_cont = True
                    elif token_type == tokenize.NEWLINE:
                        break
                        
            except (IndexError, UnicodeDecodeError):
                # signals exit of tokenizer
                pass
            except tokenize.TokenError,msg:
                _m = ("An unexpected error occurred while tokenizing input\n"
                      "The following traceback may be corrupted or invalid\n"
                      "The error message is: %s\n" % msg)
                error(_m)

            # Join composite names (e.g. "dict.fromkeys")
            names = ['.'.join(n) for n in names]
            # prune names list of duplicates, but keep the right order
            unique_names = uniq_stable(names)

            # Start loop over vars
            lvals = []
            if self.include_vars:
                for name_full in unique_names:
                    name_base = name_full.split('.',1)[0]
                    if name_base in frame.f_code.co_varnames:
                        if locals.has_key(name_base):
                            try:
                                value = repr(eval(name_full,locals))
                            except:
                                value = undefined
                        else:
                            value = undefined
                        name = tpl_local_var % name_full
                    else:
                        if frame.f_globals.has_key(name_base):
                            try:
                                value = repr(eval(name_full,frame.f_globals))
                            except:
                                value = undefined
                        else:
                            value = undefined
                        name = tpl_global_var % name_full
                    lvals.append(tpl_name_val % (name,value))
            if lvals:
                lvals = '%s%s' % (indent,em_normal.join(lvals))
            else:
                lvals = ''

            level = '%s %s\n' % (link,call)

            if index is None:
                frames.append(level)
            else:
                frames.append('%s%s' % (level,''.join(
                    _format_traceback_lines(lnum,index,lines,Colors,lvals,
                                            col_scheme))))

        # Get (safely) a string form of the exception info
        try:
            etype_str,evalue_str = map(str,(etype,evalue))
        except:
            # User exception is improperly defined.
            etype,evalue = str,sys.exc_info()[:2]
            etype_str,evalue_str = map(str,(etype,evalue))
        # ... and format it
        exception = ['%s%s%s: %s' % (Colors.excName, etype_str,
                                     ColorsNormal, evalue_str)]
        if (not py3compat.PY3) and type(evalue) is types.InstanceType:
            try:
                names = [w for w in dir(evalue) if isinstance(w, basestring)]
            except:
                # Every now and then, an object with funny inernals blows up
                # when dir() is called on it.  We do the best we can to report
                # the problem and continue
                _m = '%sException reporting error (object with broken dir())%s:'
                exception.append(_m % (Colors.excName,ColorsNormal))
                etype_str,evalue_str = map(str,sys.exc_info()[:2])
                exception.append('%s%s%s: %s' % (Colors.excName,etype_str,
                                     ColorsNormal, evalue_str))
                names = []
            for name in names:
                value = text_repr(getattr(evalue, name))
                exception.append('\n%s%s = %s' % (indent, name, value))

        # vds: >>
        if records:
             filepath, lnum = records[-1][1:3]
             #print "file:", str(file), "linenb", str(lnum) # dbg
             filepath = os.path.abspath(filepath)
             ipinst = ipapi.get()
             if ipinst is not None:
                 ipinst.hooks.synchronize_with_editor(filepath, lnum, 0)
        # vds: <<

        # return all our info assembled as a single string
        # return '%s\n\n%s\n%s' % (head,'\n'.join(frames),''.join(exception[0]) )
        return [head] + frames + [''.join(exception[0])]
Return a nice text document describing the traceback.