Python apirest for manage Google spreadsheet
First you have to create a project in the Google Developer Console. Then, for turn on the API you have to get credentials for it.
Click on OAuth consent screen tab and set a name, after that, you are ready for create project's credentials.
So you must select OAuth client ID, select the application type Other and set as name: "Google Sheets API Quickstart" and create it. At the end, download credentials json, clicking in download button, place it in your project's root and rename it as client_secret.json.