Is it possible to disable "space" as input in most tests and quizzes and clear filled field if I click on it again?

Question

Most inputs expects something but not the "space". So when I type answer and hit space by mistake (screen of a phone is too small to avoid totally such mistakes) it makes some trouble. For example, I've just passed a task in Python and there was an expected answer "len" and I didn't mention that I hit space after "le" so I tried to retype, but I still couldn't see a space. I've hit answer, got "wrong" and then try again.
I think it would be nice if a click on a filled field clears it completely.

Answer 1

A quick solution for filled fields: doubleclick -> clear -> input again.