I've never understood this extremely common complaint. First of all if one can't remember the substring method in the language they are interviewing for, that's a red flag; extremely common standard lib functions should not be a subject for googling. But let's account for nervousness, okay. If that same candidate can't find the method by googling, it's a no-hire from me, easily.

"python find substring" gives you a valid answer on every single result. This story, and most like it, is incompetence in the python language, in googling, or both.