I'm taking Raymond's advice to close this for now.  The issue tracker isn't the right place to work out ideas - python-ideas is far better for that (StackOverflow isn't a good place for that either - StackOverflow is best for when you have a very specific use case and get stuck).

While the issues with generators are common to all generators, in the context of difflib something else Raymond said should be taken to heart:  using any difflib facility is an extremely expensive way to find out that two things are equal.  That's a value of use cases!  That is, if you had asked about this on StackOverflow and asked for help instead of proposing "a (vague) solution", they would have told you at once to check whether `a == b` before dragging difflib into it.

Indeed, that's probably why what you're asking about never came up before.  People generally use difflib only when they know in advance (via a cheap equality test) that there _are_ differences to be found.

In any case, if a "specific & actionable" suggestion comes out of pursuing this, feel encouraged to open this report again!