How to use the gitdb.utils.compat.xrange function in gitdb

def _read_fanout(self, byte_offset):
        """Generate a fanout table from our data"""
        d = self._cursor.map()
        out = list()
        append = out.append
        for i in xrange(256):
            append(unpack_from('>L', d, byte_offset + i * 4)[0])
        # END for each entry
        return out

def _read_fanout(self, byte_offset):
        """Generate a fanout table from our data"""
        d = self._cursor.map()
        out = list()
        append = out.append
        for i in xrange(256):
            append(unpack_from('>L', d, byte_offset + i * 4)[0])
        # END for each entry
        return out

def offsets(self):
        """:return: sequence of all offsets in the order in which they were written

        **Note:** return value can be random accessed, but may be immmutable"""
        if self._version == 2:
            # read stream to array, convert to tuple
            a = array.array('I')    # 4 byte unsigned int, long are 8 byte on 64 bit it appears
            a.fromstring(buffer(self._cursor.map(), self._pack_offset, self._pack_64_offset - self._pack_offset))

            # networkbyteorder to something array likes more
            if sys.byteorder == 'little':
                a.byteswap()
            return a
        else:
            return tuple(self.offset(index) for index in xrange(self.size()))
        # END handle version

:param pack_sha: binary sha over the whole pack that we index
        :return: sha1 binary sha over all index file contents"""
        # sort for sha1 hash
        self._objs.sort(key=lambda o: o[0])

        sha_writer = FlexibleSha1Writer(write)
        sha_write = sha_writer.write
        sha_write(PackIndexFile.index_v2_signature)
        sha_write(pack(">L", PackIndexFile.index_version_default))

        # fanout
        tmplist = list((0,) * 256)                                # fanout or list with 64 bit offsets
        for t in self._objs:
            tmplist[byte_ord(t[0][0])] += 1
        # END prepare fanout
        for i in xrange(255):
            v = tmplist[i]
            sha_write(pack('>L', v))
            tmplist[i + 1] += v
        # END write each fanout entry
        sha_write(pack('>L', tmplist[255]))

        # sha1 ordered
        # save calls, that is push them into c
        sha_write(b''.join(t[0] for t in self._objs))

        # crc32
        for t in self._objs:
            sha_write(pack('>L', t[1] & 0xffffffff))
        # END for each crc

        tmplist = list()

:return: self"""
        slen = len(self)
        if slen < 2:
            return self
        i = 0

        first_data_index = None
        while i < slen:
            dc = self[i]
            i += 1
            if dc.data is None:
                if first_data_index is not None and i - 2 - first_data_index > 1:
                    # if first_data_index is not None:
                    nd = StringIO()                     # new data
                    so = self[first_data_index].to      # start offset in target buffer
                    for x in xrange(first_data_index, i - 1):
                        xdc = self[x]
                        nd.write(xdc.data[:xdc.ts])
                    # END collect data

                    del(self[first_data_index:i - 1])
                    buf = nd.getvalue()
                    self.insert(first_data_index, DeltaChunk(so, len(buf), 0, buf))

                    slen = len(self)
                    i = first_data_index + 1

                # END concatenate data
                first_data_index = None
                continue
            # END skip non-data chunks

def _iter_objects(self, as_stream):
        """Iterate over all objects in our index and yield their OInfo or OStream instences"""
        _sha = self._index.sha
        _object = self._object
        for index in xrange(self._index.size()):
            yield _object(_sha(index), as_stream, index)
        # END for each index