How to sign a transaction locally

Question

Is there a way in web3.py to create a wallet of accounts similar to web3.js to sign the transactions locally without building a raw transaction?

web3.js code:

var provider = new Web3.providers.WebsocketProvider(conf.networkURL);
var web3 = new Web3(provider);

const user1 = web3.eth.accounts.privateKeyToAccount(conf.accounts.user1.privateKey);
web3.eth.accounts.wallet.add(user1);

const contract = new web3.eth.Contract(contractAbi, contractAddress, { gasPrice, gas });
var result = await contract.methods.myMethod().send({ from: user1.address, gas, value });

Is there a reason to not to be that functionality?

Answer 1

Web3.py 4.0 some example ocde, might not be 100% correct as it is out from my head:

    # Set transaction parameters
    tx_data = {}
    tx_data["nonce"] = 1  # You need to manually manage account nonce if you sign tx yourself
    tx_data["gas"] = 500000
    tx_data["gasPrice"] = 21000000000

    func = contract.transfer  # ERC-20 transfer 20 tokens
    unsigned_payload = func(**args).buildTransaction(tx_data)  # Construct raw tx payload
    signed = self.web3.eth.account.signTransaction(tx_data, self.private_key_hex)  # Sign with private key
    print(signed.hash.hex())  # Hex output
    self.web3.eth.sendRawTransaction(signed.rawTransaction)

More examples here:

https://github.com/TokenMarketNet/sto/blob/master/sto/ethereum/txservice.py#L331