> What's the problem being solved by isempty? Are there any situations > that couldn't be solved by either running a type checker, or by using > len instead of bool?
I agree that determining the type is possible most of the time, either by type hints or a static analyzer. Using len is possible, with the limitation that you need a full `len(x) == 0` for numpy arrays (see discussion above). The type aspect was emphasized in the video. I'm not too worried about that explicitly. The video was more of a starting point for me to reconsider the ideom `if not users`. My conclusion (and thus proposal) differs from the video. On a technical level, everything can be solved with the current language capabilities. The main advantage is clearer semantics (explicit is better / readability counts): - Re bool: As experienced python users we are used to translate `if not users` to "if users is empty" or "if we have no users", but it *is* less explicit than `if users.is_empty()`. - Re len: `if not len(users)` or `if len(users) == 0` is more explicit, but its semantically on a lower level. Counting elements is a more detailed operation than only checking if we have any element. That detail is not needed and distracting if we are only interested in is_empty. This is vaguely similar to iterating over indices (`for i in range(len(users))`) vs. iterating over elements (`for user in users`). We don't iterate over indices because that's usually a detail we don't need. I acknowledge that discussing readability can be vague and subjective, not least because we are used to the current ideoms. I'm also aware that we should be very conservative on adding new API, in particular if it's not technically necessary. However, Python makes a strong point on readability, which IMHO is one of the major reasons for its success. I belive that in that context adding is_empty syntactic sugar would be a clear improvement. _______________________________________________ Python-ideas mailing list -- [email protected] To unsubscribe send an email to [email protected] https://mail.python.org/mailman3/lists/python-ideas.python.org/ Message archived at https://mail.python.org/archives/list/[email protected]/message/JQTXNHGJZYQL3BWNCED5WAJG2KITCFTG/ Code of Conduct: http://python.org/psf/codeofconduct/
