in reply to About \d \w and \s
My quick reaction is that the default should be /a and people should have to explicitly request /u.
To the extent it breaks existing code, I think it's in the interest of ensuring that going forward, there are the least amount of surprises for new code being written. If there's a way to "use re 'legacy_unicode'" so people can drop that at the top of their code instead of fixing every individual regex, that seems like an easy enough way to offer back compatibility.
But I firmly believe the future default should not be the legacy behavior.
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