recover.py

import rlp
from eth_keys import keys
from eth_utils import (
    decode_hex,
    is_same_address,
    big_endian_to_int,
    int_to_big_endian,
)

txn_hex = '0xf8640d843b9aca00830e57e0945b2063246f2191f18f2675cedb8b28102e957458018025a00c753084e5a8290219324c1a3a86d4064ded2d15979b1ea790734aaa2ceaafc1a0229ca4538106819fd3a5509dd383e8fe4b731c6870339556a5c06feb9cf330bb'
expected_address = '0xFeC2079e80465cc8C687fFF9EE6386ca447aFec4'


txn_parts = rlp.decode(decode_hex(txn_hex))

raw_v, r, s = tuple(map(big_endian_to_int, txn_parts[-3:]))

if raw_v <= 28:
    v = raw_v
    message = rlp.encode(txn_parts[:-3])
else:
    if raw_v % 2:  # is odd
        chain_id = (raw_v - 35) // 2
        v = 27
    else:
        chain_id = (raw_v - 36) // 2
        v = 28
    message = rlp.encode(txn_parts[:-3] + [int_to_big_endian(chain_id), b'', b''])

signature = keys.Signature(vrs=(v, r, s))
public_key = signature.recover_public_key_from_msg(message)
signed_by_address = public_key.to_address()

assert is_same_address(signed_by_address, expected_address)