Encode tuple with brownie

Question

I am trying to encode a struct as bytes with brownie and then pass the bytes as an argument to a smart contract.

contract C {
  struct S {
    uint256 a;
    uint256 b;
  }

  function f(bytes memory d) external returns (uint256, uint256) {
  S memory s = abi.decode(d, (S));
  return (s.a, s.b);
  }
}

With the contract above, how can I construct d with brownie such that it can be decoded into a struct in solidity? I see that brownie has ContractTx.encode_input(), but this requires a function signature. Thanks!

Answer 1

This can be solved with eth-abi package. Documentation can be found in https://eth-abi.readthedocs.io/en/latest/index.html.

For the example in the question, it can be called like:

import eth_abi
contract.f(eth_abi.encode_abi(['uint256', 'uint256'], [1, 2])