Type Errror during Build_Transaction expected dict-like

[mouse-trap-1]

What happened?

I'm trying to deploy a smart contract using web3.py build_transaction and signing with private key as shown below
I get an error

Code that produced the error

unsent_deploy_dao_tx = dao_contract.constructor(votingPeriod, quorum).build_transaction({   
        "from": w3.to_checksum_address(ownerAddress),
        "nonce": w3.eth.get_transaction_count(ownerAddress)
    })

signed_tx = w3.eth.account.sign_transaction(unsent_deploy_dao_tx, private_key=ownerPrivateKey)

Full error output

An error occurred: Traceback (most recent call last): File "/home/*****/Documents/blockchain-auction/main/gui/app.py", line 106, in create_dao signed_tx = w3.eth.account.sign_transaction(unsent_deploy_dao_tx, private_key=ownerPrivateKey) File "/home/*****/Documents/blockchain-auction/main/gui/venv/lib/python3.13/site-packages/eth_utils/decorators.py", line 29, in _wrapper return self.method(obj, *args, **kwargs) ~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^ File "/home/*****/Documents/blockchain-auction/main/gui/venv/lib/python3.13/site-packages/eth_account/account.py", line 834, in sign_transaction raise TypeError( f"transaction_dict must be dict-like, got {repr(transaction_dict)}" ) TypeError: transaction_dict must be dict-like, got

Fill this section in if you know how this could or should be fixed

No response

web3 Version

7.14.0

Python Version

3.13.5

Operating System

Ubuntu

Output from pip freeze

aiohappyeyeballs==2.6.1
aiohttp==3.13.2
aiosignal==1.4.0
annotated-types==0.7.0
asgiref==3.10.0
attrs==25.4.0
bitarray==3.8.0
blinker==1.9.0
certifi==2025.10.5
charset-normalizer==3.4.4
ckzg==2.1.5
click==8.2.1
cytoolz==1.1.0
eth-account==0.13.7
eth-hash==0.7.1
eth-keyfile==0.8.1
eth-keys==0.7.0
eth-rlp==2.2.0
eth-typing==5.2.1
eth-utils==5.3.1
eth_abi==5.2.0
Flask==3.1.1
frozenlist==1.8.0
hexbytes==1.3.1
idna==3.11
itsdangerous==2.2.0
Jinja2==3.1.6
MarkupSafe==3.0.2
multidict==6.7.0
parsimonious==0.10.0
propcache==0.4.1
pycryptodome==3.23.0
pydantic==2.12.4
pydantic_core==2.41.5
pyunormalize==17.0.0
regex==2025.11.3
requests==2.32.5
rlp==4.1.0
toolz==1.1.0
types-requests==2.32.4.20250913
typing-inspection==0.4.2
typing_extensions==4.15.0
urllib3==2.5.0
web3==7.14.0
websockets==15.0.1
Werkzeug==3.1.3
yarl==1.22.0

[martian7777]

Hey, Try the Following Solution if it works:

1. Cast to Dictionary (Most Likely Fix)

unsent_deploy_dao_tx = dao_contract.constructor(votingPeriod, quorum).build_transaction({   
    "from": w3.to_checksum_address(ownerAddress),
    "nonce": w3.eth.get_transaction_count(ownerAddress)
})

# FIX: Cast the transaction object to a dict before signing
tx_dict = dict(unsent_deploy_dao_tx)

signed_tx = w3.eth.account.sign_transaction(tx_dict, private_key=ownerPrivateKey)

Option 2)

if you are trying to use the 'async def' and AsyncWeb3 maybe then this might help you:

unsent_deploy_dao_tx = await dao_contract.constructor(votingPeriod, quorum).build_transaction({
    "from": w3.to_checksum_address(ownerAddress),
    "nonce": await w3.eth.get_transaction_count(ownerAddress)
})
signed_tx = w3.eth.account.sign_transaction(unsent_deploy_dao_tx, private_key=ownerPrivateKey)

If you are still not sure about what build_transction is giving and sign_tranction receives then use:

print(f"Type: {type(unsent_deploy_dao_tx)}")
print(f"Value: {unsent_deploy_dao_tx}")

• If Type is , use Option 2.

• If Type is , use Option 1.