Make a transaction hash (txid) from a hex tx, optionally along with a sighash.
    This DOES NOT WORK for segwit transactions

def btc_tx_get_hash( tx_serialized, hashcode=None ):
    """
    Make a transaction hash (txid) from a hex tx, optionally along with a sighash.
    This DOES NOT WORK for segwit transactions
    """
    if btc_tx_is_segwit(tx_serialized):
        raise ValueError('Segwit transaction: {}'.format(tx_serialized))

    tx_bin = binascii.unhexlify(tx_serialized)
    if hashcode:
        return binascii.hexlify( hashing.bin_double_sha256(tx_bin + encoding.encode(int(hashcode), 256, 4)[::-1]) )

    else:
        return binascii.hexlify( hashing.bin_double_sha256(tx_bin)[::-1] )