TypeError: a bytes-like object is required, not 'Transaction'

Question

I am trying to use the https://github.com/Python-Cardano/pycardano/blob/main/examples/native_token.py with minor changes, like pointing to mainnet (have tried preview as well). I have updated the address to point to my actual wallet and trying to create an nft. I am getting the below error

File "\Desktop\CDrive\work\Python3.7\lib\site-packages\pycardano\backend\blockfrost.py", line 230, in submit_tx self.api.transaction_submit(f.name) File "\Desktop\CDrive\work\Python3.7\lib\site-packages\blockfrost\utils.py", line 63, in error_wrapper raise ApiError(request_response) blockfrost.utils.ApiError: {'error': 'Bad Request', 'message': '"transaction read error RawCborDecodeError [DecoderErrorDeserialiseFailure \"Byron Tx\" (DeserialiseFailure 1 \"Size mismatch when decoding TxAux.\\nExpected 2, but found 4.\"),DecoderErrorDeserialiseFailure \"Shelley Tx\" (DeserialiseFailure 1 \"Size mismatch when decoding \\nRecord RecD.\\nExpected 4, but found 3.\"),DecoderErrorDeserialiseFailure \"Shelley Tx\" (DeserialiseFailure 1 \"Size mismatch when decoding \\nRecord RecD.\\nExpected 4, but found 3.\"),DecoderErrorDeserialiseFailure \"Shelley Tx\" (DeserialiseFailure 1 \"Size mismatch when decoding \\nRecord RecD.\\nExpected 4, but found 3.\"),DecoderErrorDeserialiseFailure \"Shelley Tx\" (DeserialiseFailure 79 \"expected string\"),DecoderErrorDeserialiseFailure \"Shelley Tx\" (DeserialiseFailure 79 \"expected string\")]"', 'status_code': 400}

I am not sure what is wrong, would be of great help if anyone can guide me to get it working. The same code minor change has given have also faced " File "\Desktop\CDrive\work\Python3.7\lib\tempfile.py", line 481, in func_wrapper return func(*args, **kwargs) TypeError: a bytes-like object is required, not 'Transaction'"

Below is the full python file

""" This is a complete walk through of minting a NFT on Cardano blockchain in pure Python code.

This example is inspired by https://developers.cardano.org/docs/native-tokens/minting-nfts#crafting-the-transaction

import pathlib

from blockfrost import ApiUrls

from pycardano import *

Copy your BlockFrost project ID below. Go to https://blockfrost.io/ for more information.

BLOCK_FROST_PROJECT_ID = "" NETWORK = Network.MAINNET

chain_context = BlockFrostChainContext( project_id=BLOCK_FROST_PROJECT_ID, base_url=ApiUrls.mainnet.value, #ApiUrls.preprod.value, )

"""Preparation"""

Define the root directory where images and keys will be stored.

PROJECT_ROOT = "blockfrost" root = pathlib.Path(PROJECT_ROOT) print(PROJECT_ROOT)

Create the directory if it doesn't exist

root.mkdir(parents=True, exist_ok=True)

"""Generate keys""" key_dir = root / "keys" key_dir.mkdir(exist_ok=True)

Load payment keys or create them if they don't exist

def load_or_create_key_pair(base_dir, base_name): skey_path = base_dir / f"{base_name}.skey" vkey_path = base_dir / f"{base_name}.vkey"

if skey_path.exists():
    skey = PaymentSigningKey.load(str(skey_path))
    vkey = PaymentVerificationKey.from_signing_key(skey)
else:
    key_pair = PaymentKeyPair.generate()
    key_pair.signing_key.save(str(skey_path))
    key_pair.verification_key.save(str(vkey_path))
    skey = key_pair.signing_key
    vkey = key_pair.verification_key
return skey, vkey

Payment address. Send some ADA (~5 ADA is enough) to this address, so we can pay the minting fee later.

payment_skey, payment_vkey = load_or_create_key_pair(key_dir, "payment") address = "<myWalletAddress"

address = Address(payment_vkey.hash(), network=NETWORK)

#"addr_test1qqxypmc96e3pska6ch2ucq4uv5d7uz6nhpgcne4ea4hgmemv40lpm3wmc3wqk5arjpgzrccm0m9k72puaqzwsgrj47asmp86u7" #Address(payment_vkey.hash(), network=NETWORK)

print(address)

Generate policy keys, which will be used when minting NFT

policy_skey, policy_vkey = load_or_create_key_pair(key_dir, "policy")

"""Create policy"""

A policy that requires a signature from the policy key we generated above

pub_key_policy = ScriptPubkey(policy_vkey.hash())

A time policy that disallows token minting after 10000 seconds from last block

must_before_slot = InvalidHereAfter(chain_context.last_block_slot + 10000)

Combine two policies using ScriptAll policy

policy = ScriptAll([pub_key_policy, must_before_slot])

Calculate policy ID, which is the hash of the policy

policy_id = policy.hash() print(f"Policy ID: {policy_id}") with open(root / "policy.id", "a+") as f: f.truncate(0) f.write(str(policy_id)) #****************************************************************************************************************************************** """Define NFT"""

Create an asset container

my_asset = Asset()

Create names for our assets

nft1 = AssetName(b"MY_NFT_1") nft2 = AssetName(b"MY_NFT_2")

Put assets into the asset container with a quantity of 1

my_asset[nft1] = 1 my_asset[nft2] = 1

Create a MultiAsset container

my_nft = MultiAsset()

Put assets into MultiAsset container. In this example, we only have one policy.

However, MultiAsset container can hold multiple different policies.

my_nft[policy_id] = my_asset

Create the final native script that will be attached to the transaction

native_scripts = [policy] #****************************************************************************************************************************************** """Define NFT (Alternative)"""

The nft definition above is somewhat verbose.

We can also directly create native assets from python primitives.

my_nft_alternative = MultiAsset.from_primitive( { policy_id.payload: { # Use policy ID created from above. We can't use policy_id here because policy_id's type # is ScriptHash, which is not a primitive type. Instead, we use policy_id.payload (bytes) b"MY_NFT_1": 1, # Name of our NFT1 # Quantity of this NFT b"MY_NFT_2": 1, # Name of our NFT2 # Quantity of this NFT } } )

my_nft and my_nft_alternative are equivalent

assert my_nft == my_nft_alternative #****************************************************************************************************************************************** """Create metadata"""

We need to create a metadata for our NFTs, so they could be displayed correctly by blockchain explorer

metadata = { 721: { # 721 refers to the metadata label registered for NFT standard here: # https://github.com/cardano-foundation/CIPs/blob/master/CIP-0010/registry.json#L14-L17 policy_id.payload.hex(): { "MY_NFT_1": { "description": "This is my first NFT thanks to PyCardano", "name": "PyCardano NFT example token 1", "id": 1, "image": "ipfs://QmRhTTbUrPYEw3mJGGhQqQST9k86v1DPBiTTWJGKDJsVFw", }, "MY_NFT_2": { "description": "This is my second NFT thanks to PyCardano", "name": "PyCardano NFT example token 2", "id": 2, "image": "ipfs://QmRhTTbUrPYEw3mJGGhQqQST9k86v1DPBiTTWJGKDJsVFw", }, } } }

Place metadata in AuxiliaryData, the format acceptable by a transaction.

auxiliary_data = AuxiliaryData(AlonzoMetadata(metadata=Metadata(metadata)))

"""Build transaction"""

Create a transaction builder

builder = TransactionBuilder(chain_context)

Add our own address as the input address

builder.add_input_address(address)

Since an InvalidHereAfter rule is included in the policy, we must specify time to live (ttl) for this transaction

builder.ttl = must_before_slot.after

Set nft we want to mint

builder.mint = my_nft

Set native script

builder.native_scripts = native_scripts

Set transaction metadata

builder.auxiliary_data = auxiliary_data

Calculate the minimum amount of lovelace that need to hold the NFT we are going to mint

min_val = min_lovelace( chain_context, output=TransactionOutput(address, Value(0, my_nft)) )

Send the NFT to our own address

builder.add_output(TransactionOutput(address, Value(min_val, my_nft)))

Create final signed transaction

signed_tx = builder.build_and_sign([payment_skey], change_address=address)

signed_tx = builder.build_and_sign([payment_skey, policy_skey], change_address=address)

print("############### Transaction created ###############") print("------------------------------Signed transaction------------------------------") print(signed_tx) print("-------------------------------------Signed to CBOR------------------------------") print(signed_tx.to_cbor())

Submit signed transaction to the network

print("############### Submitting transaction ###############")

chain_context.submit_tx(signed_tx)

sorki · Accepted Answer · 2023-03-30 09:44:46Z

0

I believe the error stems from the chain_context.submit_tx(signed_tx) because the API expects CBOR encoded transaction (couple lines above).

You might want to try

chain_context.submit_tx(signed_tx.to_cbor())

answered Mar 30 at 9:44

sorki

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TypeError: a bytes-like object is required, not 'Transaction'

Copy your BlockFrost project ID below. Go to https://blockfrost.io/ for more information.

Define the root directory where images and keys will be stored.

Create the directory if it doesn't exist

Load payment keys or create them if they don't exist

Payment address. Send some ADA (~5 ADA is enough) to this address, so we can pay the minting fee later.

address = Address(payment_vkey.hash(), network=NETWORK)

Generate policy keys, which will be used when minting NFT

A policy that requires a signature from the policy key we generated above

A time policy that disallows token minting after 10000 seconds from last block

Combine two policies using ScriptAll policy

Calculate policy ID, which is the hash of the policy

Create an asset container

Create names for our assets

Put assets into the asset container with a quantity of 1

Create a MultiAsset container

Put assets into MultiAsset container. In this example, we only have one policy.

However, MultiAsset container can hold multiple different policies.

Create the final native script that will be attached to the transaction

The nft definition above is somewhat verbose.

We can also directly create native assets from python primitives.

my_nft and my_nft_alternative are equivalent

We need to create a metadata for our NFTs, so they could be displayed correctly by blockchain explorer

Place metadata in AuxiliaryData, the format acceptable by a transaction.

Create a transaction builder

Add our own address as the input address

Since an InvalidHereAfter rule is included in the policy, we must specify time to live (ttl) for this transaction

Set nft we want to mint

Set native script

Set transaction metadata

Calculate the minimum amount of lovelace that need to hold the NFT we are going to mint

Send the NFT to our own address

Create final signed transaction

signed_tx = builder.build_and_sign([payment_skey, policy_skey], change_address=address)

Submit signed transaction to the network

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TypeError: a bytes-like object is required, not 'Transaction'

Copy your BlockFrost project ID below. Go to https://blockfrost.io/ for more information.

Define the root directory where images and keys will be stored.

Create the directory if it doesn't exist

Load payment keys or create them if they don't exist

Payment address. Send some ADA (~5 ADA is enough) to this address, so we can pay the minting fee later.

address = Address(payment_vkey.hash(), network=NETWORK)

Generate policy keys, which will be used when minting NFT

A policy that requires a signature from the policy key we generated above

A time policy that disallows token minting after 10000 seconds from last block

Combine two policies using ScriptAll policy

Calculate policy ID, which is the hash of the policy

Create an asset container

Create names for our assets

Put assets into the asset container with a quantity of 1

Create a MultiAsset container

Put assets into MultiAsset container. In this example, we only have one policy.

However, MultiAsset container can hold multiple different policies.

Create the final native script that will be attached to the transaction

The nft definition above is somewhat verbose.

We can also directly create native assets from python primitives.

my_nft and my_nft_alternative are equivalent

We need to create a metadata for our NFTs, so they could be displayed correctly by blockchain explorer

Place metadata in AuxiliaryData, the format acceptable by a transaction.

Create a transaction builder

Add our own address as the input address

Since an InvalidHereAfter rule is included in the policy, we must specify time to live (ttl) for this transaction

Set nft we want to mint

Set native script

Set transaction metadata

Calculate the minimum amount of lovelace that need to hold the NFT we are going to mint

Send the NFT to our own address

Create final signed transaction

signed_tx = builder.build_and_sign([payment_skey, policy_skey], change_address=address)

Submit signed transaction to the network

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Your Answer

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