def __is_valid_py_file(self, fname):
        """ tests that a particular file contains the proper file extension
            and is not in the list of files to exclude """
        is_valid_fname = 0
        for invalid_fname in self.__class__.__exclude_files:
            is_valid_fname += int(not fnmatch.fnmatch(fname, invalid_fname))
        if_valid_ext = 0
        for ext in self.__class__.__py_extensions:
            if_valid_ext += int(fnmatch.fnmatch(fname, ext))
        return is_valid_fname > 0 and if_valid_ext > 0
 tests that a particular file contains the proper file extension
            and is not in the list of files to exclude 
debugger/src/_pydev_runfiles/pydev_runfiles.py