1

Im using web3.py 6.0.0 with code:

import os
import json
from pathlib import Path
from web3 import Web3
import time
from dotenv import load_dotenv

load_dotenv()

class SmartContractInterface:
    def __init__(self, nft_contract_address: str, owner_address: str, http_provider: str, type_of_nft: str):
        self.w3Provider = Web3(Web3.HTTPProvider(http_provider))
        self.nft_contract_address = nft_contract_address
        self.owner_address = owner_address
        self.base_dir = Path(__file__).resolve().parent.parent.parent
        self.abi_path = os.path.join(self.base_dir, f"backend/utils/contract_abi/{type_of_nft}.json")
        with open(
            self.abi_path            
        ) as f:
            nftAbiJson = json.load(f)
            self.nftAbi = nftAbiJson["abi"]    
        self.nft_contract = self.w3Provider.eth.contract(address=self.nft_contract_address, abi=self.nftAbi)        
    
    def transferNftFromCustodialWallet(self, user_address: str, number_of_nft: str) -> str:
        """ Transfer NFT from custodial wallet to user Ethereum address"""
        try:
            event_filter = self.nft_contract.events["Transfer"].create_filter(
                fromBlock="latest"
            )

            ###### THIS FEW LINES ARE RELEVENT FOR THIS QUESTION ########
            self.nft_contract.functions.transferFrom(self.owner_address, user_address,int(number_of_nft)).transact(
                {"from": self.owner_address}
            )
            ###########################################################

            events = event_filter.get_new_entries()
            for event in events:
                if event["event"] == "Transfer":
                    return (True, event) 
                else:
                    return (False)
        except Exception as e:
            return e

Where for owner address I use eth address of NFT token owner who have rights to make this transfer.

But now I'm puzzled how web3.py know which private keys he should use to sign this transaction just by knowing public address? From where does he gets this private keys?

It looks like some web3.py magic is involved under the hood? I don`t have other explanation...Some ideas?

2
  • Please share all your code. Moreover, are you certain a transaction is correctly sent AND mined ? Apr 27, 2023 at 11:26
  • Here is updated code from the class....When I test with my local Ganache environment transaction is done properly. Still I didn`t test on some testent....
    – Ilija
    Apr 27, 2023 at 11:36

1 Answer 1

0

Its hard to tell without more code, but...

Didn't you do import brownie at the start of your file/script?

Then maybe you did from brownie import accounts followed by owner_address = accounts[0] or something like that?

That would be enough to make it work.

1
  • I added code for whole class. You can take a look now....
    – Ilija
    Apr 27, 2023 at 11:39

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