如何从特定地址调用合同功能

Question

I want to use web3 to call a contract function(sendTransaction not call) from a specific address that I hold the private key to. I also have the contract instance connected. I know I have to dio something like web3.personal.unlockAccount(address,password,duration) And then specify the from address. So my question is, is "password" where I enter my private key? And how do I pass that address into fromAddress once I unlock it. Or is there a more streamlined way to go about it?

Answer 1

is "password" where I enter my private key?

No , it's not. Actually it is a password, which you entered when you were creating account and which was used to generate your keystore file.

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If you use web3.personal.unlockAccount(address,password,duration) you need to have your keystore file in the keystore folder near chaindata of geth.

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Another way will be to use web3.eth.sendRawTransaction from web3.py , but it will be a little bit clunky to call contract method from it.

key = '0x' + 'YOUR-PRIVATE-KEY
transaction = {
    'to': _to,
    'value': 0,
    'gas': 300000,
    'gasPrice': 23000000000,
    'nonce': web3.eth.getTransactionCount(_from),
    'chainId': int(web3.admin.nodeInfo['protocols']['eth']['network']),
    'data': b''
}

signed = web3.eth.account.signTransaction(transaction, key)
print("Transaction Hash: " + web3.toHex(web3.eth.sendRawTransaction(signed.rawTransaction)))

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My suggestion will be to create keyfile recognisable by Ethereum clients by using web3.eth.account.encrypt ( web3.py because web3.js yet lack this functionality) and after you generate it put it in the right folder and try simply to unlock account.