Function read_bytes4

Lib/pickletools.py:500–521

r""" >>> import io >>> read_bytes4(io.BytesIO(b"\x00\x00\x00\x00abc")) b'' >>> read_bytes4(io.BytesIO(b"\x03\x00\x00\x00abcdef")) b'abc' >>> read_bytes4(io.BytesIO(b"\x00\x00\x00\x03abcdef")) Traceback (most recent call last): ... ValueError: expected 50331648 byt

(f)

def read_bytes4(f):
    r"""
    >>> import io
    >>> read_bytes4(io.BytesIO(b"\x00\x00\x00\x00abc"))
    b''
    >>> read_bytes4(io.BytesIO(b"\x03\x00\x00\x00abcdef"))
    b'abc'
    >>> read_bytes4(io.BytesIO(b"\x00\x00\x00\x03abcdef"))
    Traceback (most recent call last):
    ...
    ValueError: expected 50331648 bytes in a bytes4, but only 6 remain
    """

    n = read_uint4(f)
    assert n >= 0
    if n > sys.maxsize:
        raise ValueError("bytes4 byte count > sys.maxsize: %d" % n)
    data = f.read(n)
    if len(data) == n:
        return data
    raise ValueError("expected %d bytes in a bytes4, but only %d remain" %
                     (n, len(data)))

bytes4 = ArgumentDescriptor(
              name="bytes4",