How to use the gprof2dot.Parser function in gprof2dot

function_id = process + '!' + symbol

        try:
            function = self.profile.functions[function_id]
        except KeyError:
            module, name = symbol.split('!', 1)
            function = Function(function_id, name)
            function.process = process
            function.module = module
            function[SAMPLES] = 0
            self.profile.add_function(function)

        return function


class SleepyParser(Parser):
    """Parser for GNU gprof output.

    See also:
    - http://www.codersnotes.com/sleepy/
    - http://sleepygraph.sourceforge.net/
    """

    stdinInput = False

    def __init__(self, filename):
        Parser.__init__(self)

        from zipfile import ZipFile

        self.database = ZipFile(filename)

#   - In the absence of call counts, call ratios are faked from the relative
#     proportions of total time.  This affects only the weighting of the calls.
#   - Different header, separator, and end marker.
#   - Extra whitespace after function names.
#   - You get a full entry for , which does not have parents.
#   - Cycles do have parents.  These are saved but unused (as they are
#     for functions).
#   - Disambiguated "unrecognized call graph entry" error messages.
# Notes:
#   - Total time of functions as reported by AXE passes the val3 test.
#   - CPU Time:Children in the input is sometimes a negative number.  This
#     value goes to the variable descendants, which is unused.
#   - The format of gprof-cc reports is unaffected by the use of
#       -knob enable-call-counts=true (no call counts, ever), or
#       -show-as=samples (results are quoted in seconds regardless).
class AXEParser(Parser):
    "Parser for VTune Amplifier XE 2013 gprof-cc report output."

    def __init__(self, fp):
        Parser.__init__(self)
        self.fp = fp
        self.functions = {}
        self.cycles = {}

    def readline(self):
        line = self.fp.readline()
        if not line:
            sys.stderr.write('error: unexpected end of file\n')
            sys.exit(1)
        line = line.rstrip('\r\n')
        return line

class Parser:
    """Parser interface."""

    stdinInput = True
    multipleInput = False

    def __init__(self):
        pass

    def parse(self):
        raise NotImplementedError

    
class JsonParser(Parser):
    """Parser for a custom JSON representation of profile data.

    See schema.json for details.
    """


    def __init__(self, stream):
        Parser.__init__(self)
        self.stream = stream

    def parse(self):

        obj = json.load(self.stream)

        assert obj['version'] == 0

def __init__(self, stream):
        Parser.__init__(self)
        self.stream = stream

def pos(self):
        return self.parser.CurrentLineNumber, self.parser.CurrentColumnNumber


class XmlTokenMismatch(Exception):

    def __init__(self, expected, found):
        Exception.__init__(self)
        self.expected = expected
        self.found = found

    def __str__(self):
        return '%u:%u: %s expected, %s found' % (self.found.line, self.found.column, str(self.expected), str(self.found))


class XmlParser(Parser):
    """Base XML document parser."""

    def __init__(self, fp):
        Parser.__init__(self)
        self.tokenizer = XmlTokenizer(fp)
        self.consume()
    
    def consume(self):
        self.token = self.tokenizer.next()

    def match_element_start(self, name):
        return self.token.type == XML_ELEMENT_START and self.token.name_or_data == name
    
    def match_element_end(self, name):
        return self.token.type == XML_ELEMENT_END and self.token.name_or_data == name

callee = caller

        if False:
            profile.dump()

        # compute derived data
        profile.validate()
        profile.find_cycles()
        profile.ratio(TIME_RATIO, SAMPLES)
        profile.call_ratios(SAMPLES2)
        profile.integrate(TOTAL_TIME_RATIO, TIME_RATIO)

        return profile


class LineParser(Parser):
    """Base class for parsers that read line-based formats."""

    def __init__(self, stream):
        Parser.__init__(self)
        self._stream = stream
        self.__line = None
        self.__eof = False
        self.line_no = 0

    def readline(self):
        line = self._stream.readline()
        if not line:
            self.__line = ''
            self.__eof = True
        else:
            self.line_no += 1