pickletools.py 文件源码

def read_float8(f):
    r"""
    >>> import io, struct
    >>> raw = struct.pack(">d", -1.25)
    >>> raw
    b'\xbf\xf4\x00\x00\x00\x00\x00\x00'
    >>> read_float8(io.BytesIO(raw + b"\n"))
    -1.25
    """

    data = f.read(8)
    if len(data) == 8:
        return _unpack(">d", data)[0]
    raise ValueError("not enough data in stream to read float8")