Ezio Melotti added the comment: I believe this is not a bug. As the error says a look-behind requires the pattern to have a fixed length.
In re.search(r'(?<=(a|b))(\w+)', 'abc').groups() the two possible patterns in the look behind are "a" and "b", both with length 1. In re.search(r'(?<=(^|$))(\w+)', 'abc').groups() the two possible patterns in the look behind are "^" and "$", both with length 0. In re.search(r'(?<=(^|a))(\w+)', 'abc').groups() the two possible patterns in the look behind are "^" and "a", one with length 0 and the other with length 1. This is not allowed and raises an error. Similarly, in re.search(r'(?<=(ab|a))(\w+)', 'abc').groups() the two patterns have length 2 and 1, and the same error is raised. Closing as not a bug. ---------- resolution: -> not a bug stage: -> resolved status: open -> closed _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue14069> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
