import requests with open('status.json.in') as st_in: content = st_in.read() obj = requests.get("http://api.open-notify.org/iss-now.json").json() lat = obj['iss_position']['latitude'] lon = obj['iss_position']['longitude'] with open('status.json', 'w') as st_out: st_out.write(content % (lat, lon))