urllib.py 文件源码

def noheaders():
    """Return an empty mimetools.Message object."""
    global _noheaders
    if _noheaders is None:
        import mimetools
        try:
            from cStringIO import StringIO
        except ImportError:
            from StringIO import StringIO
        _noheaders = mimetools.Message(StringIO(), 0)
        _noheaders.fp.close()   # Recycle file descriptor
    return _noheaders


# Utility classes