pickletools.py 文件源码

def read_long4(f):
    r"""
    >>> import StringIO
    >>> read_long4(StringIO.StringIO("\x02\x00\x00\x00\xff\x00"))
    255L
    >>> read_long4(StringIO.StringIO("\x02\x00\x00\x00\xff\x7f"))
    32767L
    >>> read_long4(StringIO.StringIO("\x02\x00\x00\x00\x00\xff"))
    -256L
    >>> read_long4(StringIO.StringIO("\x02\x00\x00\x00\x00\x80"))
    -32768L
    >>> read_long1(StringIO.StringIO("\x00\x00\x00\x00"))
    0L
    """

    n = read_int4(f)
    if n < 0:
        raise ValueError("long4 byte count < 0: %d" % n)
    data = f.read(n)
    if len(data) != n:
        raise ValueError("not enough data in stream to read long4")
    return decode_long(data)