Import a function from a python file specified in the arguments.

import_module.py

import sys
import argparse
import importlib

def import_function_handle(config_file):
    file_path = [ROOT DIRECTORY WHERE YOUR PYTHON FILE EXIST]/{}.py'
    file_path = file_path.format(config_file)
    if not os.path.isfile(file_path):
        print("\033[31;40mSuch a config file does not exist, check name ...\033[m")
        print("\033[31;40mCurrent specified path: {}\033[m".format(file_path))
        exit(0)
    spec = importlib.util.spec_from_file_location('config', file_path.format(config_file))
    spec_module = importlib.util.module_from_spec(spec)
    sys.modules['config'] = spec_module
    spec.loader.exec_module(spec_module)
    from config import function_handle
    return function_handle
  
parser.add_argument('--filename', type=str, default='somefile', help='check bic_policies/config')
args = parser.parse_args()
funtion_handle = import_function_handle(args.filename)