In order to implement `f` as a plain function with same behaviour as g-strings, you would probably have to do some stack trickery to properly capture locals. I

In order to implement `f` as a plain function with same behaviour as g-strings, you would probably have to do some stack trickery to properly capture locals. In fact, I don't think it would be possible to write such a function in the general case, because it's ambiguous what environment you would need to use. For example: def call(func, arg): a = 2 return func(arg) a = 1 print(call(f, "{a}")) Does this print 1 or 2?