Is it possible to create false positives, aka “throwing exception” on purpose in solidity?

I’ve been playing with this over the past weekend and it seems impossible, I guess since it’s considered a big security issue if it was possible. Example to illustrate what I am trying to achieve: msg.sender sends something; contract waits for confirmation if tx succeeds; if tx does/doesn’t: do something Challenge: claim tx failed despite…

Why does this code outputs error:”unknown account”?

from web3 import Web3 import json web = “http://10.0.141.114:8545” web3 = Web3(Web3.HTTPProvider(web)) abi=json.loads(‘[ { “constant”: false, “inputs”: [ { “name”: “_cad_number”, “type”: “uint256” }, { “name”: “_num”, “type”: “uint256” } ], “name”: “create_pledge”, “outputs”: [], “payable”: false, “stateMutability”: “nonpayable”, “type”: “function”, “signature”: “0x113a5bac” }, { “constant”: false, “inputs”: [ { “name”: “_cad_number”, “type”: “uint256” }…