Access_data.py

import pickle 
import psycopg2

# loading the file containing credentials
with open("heroku_database_credentials.pickle", "rb") as cred: 
  credential = pickle.load(cred)

# connecting to the postgresql database with those credentials
conn = psycopg2.connect(database=credential['Database'], 
                        host=credential['Host'], 
                        user=credential['User'], 
                        port=credential['Port'], 
                        password=credential['Password'])