Guido van Rossum wrote: > So then the next question is, what's the use case? What code are people > writing that may receive either a stdlib container or a numpy array, and > which needs to do something special if there are no elements? Maybe > computing the average? AFAICT Tim Hoffman (the OP) never said.
There's two parts to the answer: 1) There functions e.g. in scipy and matplotlib that accept both numpy arrays and lists of flows. Speaking from matplotlib experience: While eventually we coerce that data to a uniform internal format, there are cases in which we need to keep the original data and only convert on a lower internal level. We often can return early in a function if there is no data, which is where the emptiness check comes in. We have to take extra care to not do the PEP-8 recommended emptiness check using `if not data`. 2) Even for cases that cannot have different types in the same code, it is unsatisfactory that I have to write `if not seq` but `if len(array) == 0` depending on the expected data. IMHO whatever the recommended syntax for emptiness checking is, it should be the same for lists and arrays and dataframes. _______________________________________________ Python-ideas mailing list -- python-ideas@python.org To unsubscribe send an email to python-ideas-le...@python.org https://mail.python.org/mailman3/lists/python-ideas.python.org/ Message archived at https://mail.python.org/archives/list/python-ideas@python.org/message/Q6KZEXFLJ6TEFSDQM3SXXIVGNFNURPYT/ Code of Conduct: http://python.org/psf/codeofconduct/
