Thank you! I just did a quick `git grep` in a work code base and found one clear instance of this bug, and two more locations where I'm not 100% certain whether

Thank you! I just did a quick `git grep` in a work code base and found one clear instance of this bug, and two more locations where I'm not 100% certain whether references are kept around long enough. Made a note to open a bug on Monday :-) Another surprise in python's base library: I knew that re.search searches for a regex match in a string, so I thought that re.match would match the whole string. I was wrong, re.match only anchors the regex at the start, not the end. re.fullmatch anchors it at both sides. I felt very stupid when I found out; I started at my current work as a Perl developer and learned Python for a new job; but there are two more Python developers (with previous Python experience outside this company) on the same project, and none of them noticed the mistakes I made based on this misunderstanding.