Build & Sign Transaction using PyCardano
========================================

This module uses PyCardano to build, sign, and submit a transaction: ::

    import pycardano as pyc

    network = pyc.Network.TESTNET

    # Read keys to memory
    psk = pyc.PaymentExtendedSigningKey.load("./tests/test_wallet/test_addr0.skey")
    ssk = pyc.StakeExtendedSigningKey.load("./tests/test_wallet/test_stake.skey")

    pvk = pyc.PaymentVerificationKey.from_signing_key(psk)
    svk = pyc.StakeVerificationKey.from_signing_key(ssk)

    # Derive an address from payment verification key and stake verification key
    address = pyc.Address(pvk.hash(), svk.hash(), network)

    # Create an Ogmios chain context. In this example, we will use preprod network.
    context = pyc.OgmiosV6ChainContext("localhost", 1337)

    # Create a transaction builder
    builder = pyc.TransactionBuilder(context)

    # Tell the builder that transaction input will come from a specific address, assuming that there are some ADA and native
    # assets sitting at this address. "add_input_address" could be called multiple times with different address.
    builder.add_input_address(address)

    # Get all UTxOs currently sitting at this address
    utxos = context.utxos(address)

    # We can also tell the builder to include a specific UTxO in the transaction.
    # Similarly, "add_input" could be called multiple times.
    builder.add_input(utxos[0])

    builder.add_output(
        pyc.TransactionOutput(
            pyc.Address.from_primitive(
                "addr_test1vrm9x2zsux7va6w892g38tvchnzahvcd9tykqf3ygnmwtaqyfg52x"
            ),
            pyc.Value.from_primitive(
                [
                    1500000,
                ]
            ),
        )
    )

    # We can add multiple outputs, similar to what we can do with inputs.
    # Send 2 ADA and a native asset (CHOC) in quantity of 200 to ourselves
    builder.add_output(
        pyc.TransactionOutput(
            address,
            pyc.Value.from_primitive(
                [
                    2000000,
                    {
                        bytes.fromhex(
                            "57fca08abbaddee36da742a839f7d83a7e1d2419f1507fcbf3916522"  # Policy ID
                        ): {
                            b"CHOC": 200  # Asset name and amount
                        }
                    },
                ]
            ),
        )
    )

    # Create final signed transaction
    signed_tx = builder.build_and_sign([psk], change_address=address)
    print(signed_tx)

    # Submit signed transaction to the network
    context.submit_tx(signed_tx)


`Open this example on GitLab <https://gitlab.com/viperscience/ogmios-python/-/blob/main/examples/build_tx_pycardano.py>`_