TypeError: string indices must be integers

Question

Hello there I'm currently following this tutorial https://www.youtube.com/watch?v=M576WGiDBdQ by Patrick Collins. I have a problem when I try to deploy the script:

(base) elly@elly-Lenovo-G50-80:~/smartcontract_lottery$ brownie run scripts/deploy.py

Brownie v1.19.0 - Python development framework for Ethereum
SmartcontractLotteryProject is the active project.
  File "brownie/_cli/__main__.py", line 64, in main
    importlib.import_module(f"brownie._cli.{cmd}").main()
  File "brownie/_cli/run.py", line 45, in main
    network.connect(CONFIG.argv["network"])
  File "brownie/network/main.py", line 31, in connect
    active = CONFIG.set_active_network(network)
  File "brownie/_config.py", line 74, in set_active_network
    id_ = self.settings["networks"]["default"]
TypeError: string indices must be integers

I will include all the files:

1. Lottery.sol

// SPDX-License-Identifier:MIT
pragma solidity ^0.6.6;

import "@chainlink/contracts/src/v0.6/interfaces/AggregatorV3Interface.sol";
import "@openzeppelin/contracts/access/Ownable.sol";
import "@chainlink/contracts/src/v0.6/VRFConsumerBase.sol";

contract Lottery is VRFConsumerBase, Ownable {
    address payable[] public players;
    address payable public recentWinner;
    uint256 public randomness;
    uint256 public usdEntryFee;
    AggregatorV3Interface internal ethUsdPriceFeed;

    enum LOTTERY_STATE {
        OPEN,
        CLOSED,
        CALCULATING_WINNER
    }

    LOTTERY_STATE public lottery_state;
    uint256 public fee;
    bytes32 public keyhash;

    constructor(
        address _priceFeedAddress,
        address _vrfCoordinator,
        address _link,
        uint256 _fee,
        bytes32 _keyhash
    ) public VRFConsumerBase(_vrfCoordinator, _link) {
        usdEntryFee = 50 * (10**18);
        ethUsdPriceFeed = AggregatorV3Interface(_priceFeedAddress);
        lottery_state = LOTTERY_STATE.CLOSED;
        fee = _fee;
        keyhash = _keyhash;
    }

    function enter() public payable {
        require(lottery_state == LOTTERY_STATE.OPEN);
        require(msg.value >= getEntranceFee(), "Not enough ETH!");
        players.push(msg.sender);
    }

    function getEntranceFee() public view returns (uint256) {
        (, int256 price, , , ) = ethUsdPriceFeed.latestRoundData();
        uint256 adjustedPrice = uint256(price) * 10**10;
        uint256 costToEnter = (usdEntryFee * 10**18) / adjustedPrice;
        return costToEnter;
    }

    function startLottery() public {
        require(
            lottery_state == LOTTERY_STATE.CLOSED,
            "Can't start a new lottery yet!"
        );
        lottery_state == LOTTERY_STATE.OPEN;
    }

    function endLottery() public onlyOwner {
        lottery_state = LOTTERY_STATE.CALCULATING_WINNER;
        bytes32 requestId = requestRandomness(keyhash, fee);
    }

    function fulfillRandomness(bytes32 _requestId, uint256 _randomness)
        internal
        override
    {
        require(
            lottery_state == LOTTERY_STATE.CALCULATING_WINNER,
            "You are not there yet!"
        );
        require(_randomness > 0, "random-not-found");
        uint256 indexOfWinner = _randomness % players.length;
        recentWinner = players[indexOfWinner];
        recentWinner.transfer(address(this).balance);
        //Reset
        players = new address payable[](0);
        lottery_state = LOTTERY_STATE.CLOSED;
        randomness = _randomness;
    }
}

2. Deploy_lottery.py

from scripts.helpful_scripts import get_account


def deploy_lottery():
    account= get_account()


def main():
    deploy_lottery()

3.Brownie-config.yaml

dependencies:
  - smartcontractkit/[email protected]
  - OpenZeppelin/[email protected]
compiler:
  solc:
    remappings:
      - '@chainlink=smartcontractkit/[email protected]' 
      - '@openzeppelin=OpenZeppelin/[email protected]'
networks: 'development'
mainnet-fork:
    eth_usd_price_feed: '0x5f4eC3Df9cbd43714FE2740f5E3616155c5b8419'      
wallets:
from_key: ${PRIVATE_KEY}    

4.Helpful_scripts.py

from brownie import accounts, network, config

FORKED_LOCAL_ENVIRONMENTS= ["mainnet-fork", "mainnet-fork-dev"]
LOCAL_BLOCKCHAIN_ENVIRONMENTS= ["development", "ganache-local"]


def get_account(index=None, id=None):
    if index:
        return accounts[index]
    if id:
        return accounts.load(id)
    if (
        network.show_active() in LOCAL_BLOCKCHAIN_ENVIRONMENTS
        or network.show_active() in FORKED_LOCAL_ENVIRONMENTS
    ):
        return accounts[0]
        
    return accounts.add(config["wallets"]["from_key"])

5. Test_lottery.py

from brownie import Lottery, accounts, config, network
from web3 import Web3


def test_get_entrance_fee():
    account=accounts[0]
    lottery=Lottery.deploy(
        config["networks"][network.show_active()]["eth_usd_price_feed"],
         {"from": account},
         )
#assert lottery.getEntranceFee()> Web3.toWei(0.018, "ether")
#assert lottery.getEntranceFee()< Web3.toWei(0.02, "ether")

Answer 1

I don't know, but looks like your Brownie config is not correct, can you try this file please:

dependencies:
  - smartcontractkit/[email protected]
  - OpenZeppelin/[email protected]
compiler:
  solc:
    remappings:
      - '@chainlink=smartcontractkit/[email protected]' 
      - '@openzeppelin=OpenZeppelin/[email protected]'
networks:
      default: 'development'
mainnet-fork:
    eth_usd_price_feed: '0x5f4eC3Df9cbd43714FE2740f5E3616155c5b8419'      
wallets:
from_key: ${PRIVATE_KEY}

Specifically notice the networks key which now has a sub-key called default. Also, in the following example, the config file seems to need the default key under the networks key: https://eth-brownie.readthedocs.io/en/stable/config.html

There is more evidence in your error: It looks like the error happens right on this line id_ = self.settings["networks"]["default"], notice how it's trying to access the networks/default "path" in your config file.

But in the file you shared, that path does not exist.