is "_io.py" missing from 2.7.4 ?

[dbv]

In 2.7.4, io.py shows:

import _io
import abc

from _io import (DEFAULT_BUFFER_SIZE, BlockingIOError, UnsupportedOperation,
                 open, FileIO, BytesIO, StringIO, BufferedReader,
                 BufferedWriter, BufferedRWPair, BufferedRandom,
                 IncrementalNewlineDecoder, TextIOWrapper)

but, cannot find _io.py, though there is the old _pyio.py in the //Python27//Lib folder.