contract function invoked by web3py without error but have no effect (ganache local network)

Question

compiled code by py-solc-x, then deployed it to the ganache local network using web3py api. first, call a get_balance function and it return as expected. second, call the transfer function and it return without error, but the balance have not changed when I call get_balance later. try to call transfer by sending a raw transaction but it still no effect...

metacoin.sol (provided by truffle doc)

pragma solidity ^0.8.0;

contract MetaCoin {

    mapping (address => uint) balances;

    event Transfer(address indexed _from, address indexed _to, uint _value);    

    constructor() public {
        balances[msg.sender] = 10000;
    }

    function transfer(address receiver, uint amount) public returns(bool sufficient) {
        if (balances[msg.sender] >= amount)
            return false;

        balances[msg.sender] -= amount;
        balances[receiver] += amount;
        emit Transfer(msg.sender, receiver, amount);   
        return true;
    }

    function get_balance(address account) public view returns(uint) {
        return balances[account];
    }
}

interacting.py

    # deploy contract by w3.eth.accounts[0]
    # the balance of the accounts[0] is 10000 (call get_balance() return 10000)
    # then transfer 1000 from accounts[0] to accounts[1]

    deployed_address = '0x538574C591F6e01E22eFa951153a29e6Fc505735'
    contract = w3.eth.contract(address=HexBytes(deployed_address), abi=abi)
    tx_hash = contract.functions.transfer(w3.eth.accounts[1], 1000).transact()
    tx_receipt = w3.eth.wait_for_transaction_receipt(tx_hash)
    print(tx_receipt.contractAddress)

    balance = contract.functions.get_balance(w3.eth.accounts[0]).call()
    print(balance)    
    # still 10000, expect 9000.

the transfer transaction looks good. both gas/gasPrice and dynamic fee transaction have been tried but the balance still the same. it's the problem from the ganache local network setting ? or some required configured steps I missed.

Answer 1

Check that the transaction went through

assert tx_receipt.status == 1

Also if Ganache does not work then try Ethereum Tester based tests. Example token tests here.