There's no ambiguity though, right? [0x for x in (1,2,3)] is nonsense (one typo off from something legitimate, but nonsense regardless). I can't think of another way someone might expect this to parse.
[0x1for x in (1,2,3)]
looks like it should parse as [0x1 for x in (1,2,3)]
but instead parses as [0x1f or x in (1,2,3)]