ConfigParser: Check If variable in Config File exists

Question

I am currently trying to check if my config file has a variable in it. In the documentation I only saw a check for the sections but not a variable inside the section.

Current code:

#!/usr/bin/python3
from configparser import ConfigParser

def ImportConfig(arg):
    config_file = ConfigParser()
    config_file.read("configFile")
    config = config_file[""+arg+""]
    
    If config['variable'] exists:
        do something...

arg is the section name that I give my script as a parameter.