def sign_all_unsigned_inputs(hex_privkey, unsigned_tx_hex):
    """
        Sign a serialized transaction's unsigned inputs

        @hex_privkey: private key that should sign inputs
        @unsigned_tx_hex: hex transaction with unsigned inputs

        Returns: signed hex transaction
    """
    inputs, outputs, locktime, version = deserialize_transaction(unsigned_tx_hex)
    tx_hex = unsigned_tx_hex
    for index in xrange(0, len(inputs)):
        if len(inputs[index]['script_sig']) == 0:

            # tx with index i signed with privkey
            tx_hex = sign_transaction(str(unsigned_tx_hex), index, hex_privkey)
            unsigned_tx_hex = tx_hex

    return tx_hex
Sign a serialized transaction's unsigned inputs

        @hex_privkey: private key that should sign inputs
        @unsigned_tx_hex: hex transaction with unsigned inputs

        Returns: signed hex transaction