Python function to get city/state from Google Maps API when provided a valid zip/postal code.
A new city/state is only returned from the API when they're not passed in or blank ones are passed in, to prevent over-writing existing data.
Replace GetYourOwnGoogleMapsApiKey with a Google API key from https://developers.google.com/maps/signup
Accepts:
- zip - string (required) Any valid postal code.
- city - string (optional) Won't be overwritten if provided.
- country - string, 2 letter iso code
- state - string (optional) Won't be overwritten if provided.
Returns:
- zip - unmodified
- city - string from Google API
- country - unmodified
- state - string from Google API