struct.error

def classes():
 
    from cPickle import dumps, loads, UnpicklingError, HIGHEST_PROTOCOL
    from struct import pack, unpack, error as StructError
    try:
        from struct import Struct
    except ImportError:

        def read_bytes(self):
            count = unpack_int(self.file.read(4))[0]
            value = self.file.read(count)
            if _len(value) != count:
                raise StructError("EOF before reading all of bytes type")
            return value
 

        def read_string(self):
            count = unpack_int(self.file.read(4))[0]
            value = self.file.read(count)
            if _len(value) != count:
                raise StructError("EOF before reading all of string")
            return value
 
        read_bytestring = read_string
 
        def read_unicode(self):
            count = unpack_int(self.file.read(4))[0]
            value = self.file.read(count)
            if _len(value) != count:
                raise StructError("EOF before reading all of string")

        def read_vector(self):
            r = self._read
            count = unpack_int(self.file.read(4))[0]
            try:
                return tuple(r() for i in xrange(count))
            except StopIteration:
                raise StructError("EOF before all vector elements read")
 
        def read_list(self):
            value = list(self._reads())
            if self.eof:
                raise StructError("EOF before end-of-list marker")

        def read_pickle(self):
            count = unpack_int(self.file.read(4))[0]
            bytes = self.file.read(count)
            if _len(bytes) != count:
                raise StructError("EOF before reading all of bytes type")
            return loads(bytes)
 
        def read_marker(self):
            raise StopIteration
 
        def invalid_typecode(self):
            raise StructError("Invalid type byte: " + str(self.t))

            try:
                value = self._read()
            except StopIteration:
                raise StructError('EOF before second item in pair')
            return key, value
 
        def reads(self):

                try:
                    value = next()
                except StopIteration:
                    raise StructError('EOF before second item in pair')
                yield key, value
 
        __iter__ = reads