def set_privkey_compressed(privkey, compressed=True):
    """
    Make sure the private key given is compressed or not compressed
    """
    if len(privkey) != 64 and len(privkey) != 66:
        raise ValueError("expected 32-byte private key as a hex string")

    # compressed?
    if compressed and len(privkey) == 64:
        privkey += '01'

    if not compressed and len(privkey) == 66:
        if privkey[-2:] != '01':
            raise ValueError("private key does not end in '01'")

        privkey = privkey[:-2]

    return privkey
Make sure the private key given is compressed or not compressed