Yes there is, you shouldn't go too crazy in terms of request frequency when using the Google Sheets API. Calls are limited to 300 read requests per minute per project, even further limited to 60 read requests per user per minute per project. The same limit applies to write requests (300 per minute per project, 60 per user per minute per project). So if you're mixing read & write requests, you'll have basically a maximum of 1 request per second. Hence the need to use time.sleep( ) commands in your Python code.