connect_smart_contract.py

# This pyth file is a module for connecting to the Ethereum network and interaction with Ethereum smart contract.
# Then he imports the necessary modules from the Web3 library, 
# which allow you to connect to Ethereum and operate with smart contracts.
# To launch the script, it is necessary to install the web3 library and the python-dotenv library
# pip install python-dotenv
# pip install web3

import settings

from web3 import Web3
from web3.middleware import geth_poa_middleware

import os
from dotenv import load_dotenv
from abi import abi

load_dotenv()

INFURA_PROJECT_ID = os.environ.get('INFURA_PROJECT_ID')
ADDRESS_CONTRACT = os.environ.get('ADDRESS_CONTRACT')
# ABI has a string format taken, for example, from Etherscan
ABI = abi
PRIVATE_KEY = os.environ.get('PRIVATE_KEY')

def connect_eth():
    
    # connect to eth
    w3 = Web3(Web3.HTTPProvider(settings.INFURA_PROJECT_ID))

    # прослойка между сетями
    w3.middleware_onion.inject(geth_poa_middleware, layer=0)

    # проверка подключения
    assert True is w3.is_connected(), settings.INFURA_PROJECT_ID

    return w3
  
# функция пре-создания контракта
def connect_smart_contract():
    # connect to eth
    w3 = connect_eth()
        
    # variables from env file
    address_contract = settings.ADDRESS_CONTRACT
    abi = settings.ABI
        
    # smart-contract
    contract_instance = w3.eth.contract(address=address_contract, abi=abi)

    # info from blockchain      
    block = w3.eth.get_block('latest').number
    gas_price = w3.eth.gas_price
    # info about smart-contract
    contract_name = contract_instance.functions.name().call()
    
    return contract_instance, block, gas_price, w3, contract_name

eth_info = connect_smart_contract()