>  i demonstrated replacing _all_of them at once, not replacing them each by hand.

Not really, that is search and replace. IDE's do typesafe refactoring. If you change the Find method in class A, you should only change occurences of x.foo(), where x has type A. You shouldn't accidentally change all B.find()'s.

That is my advice for everyone completing their first Python tutorial: learn a typed language next if you aspire to do serious work. It also saves you writing many manual tests that you had to make otherwise, as the compiler makes that superfluous. Plus your IDE becomes a superpower.