pickletools.py 文件源码

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

    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)