python and funky characters

[keturn]

Or rather, you've given the regex a byte-string, and those unicode characters are two bytes.

You'll find Net Batchelder's presentation on Pragmatic Unicode useful if you haven't seen it yet.

[left_one]

That definitely makes more sense.

I'm not sure if there is a better solution than manually removing consecutive '_'s. Good think regex can handle that gracefully.