Python script running on GAE(App Engine) can read a Google Sheet without credentials

[meenakshisundar]

Consider a python script running on App Engine, is it possible to access particular Google Sheet that has been shared with app engine default service account of that GCP project where the python scrip is deployed.

Is it possible to build the service endpoint for Google Sheets API

service = build('sheets', 'v4', credentials=creds) # without passing credentials parameter explicitly

without passing credentials file explicitly, is it possible for App Engine app(python script) to take default App Engine service account implicitly(like it dose for Cloud services)