On Fri, 30 Apr 2021 at 17:08, David Álvarez Lombardi <alvarezd...@gmail.com> wrote:
> I propose a syntax for constructing/filtering strings analogous to the one > available for all other builtin iterables. It could look something like > this. > > >>> dirty = "f8sjGe7" > >>> clean = c"char for char in dirty if char in string.ascii_letters" > >>> clean > 'fsjGe' > > Currently, the best way to do this (in the general case) seems to be the > following. > >>> clean = "".join(char for char in dirty if char in string.ascii_letters) > > But I think the proposed syntax would be superior for two main reasons. > I’m not against a specialised string generator construct per-se (I’m not for it either :) as it’s not a problem I have experienced, and I’ve been doing a lot of string parsing/formatting at scale recently) but that doesn’t mean your use-cases are invalid. To me, the chosen syntax is problematic. The idea of introducing structural logic by using “” seems likely to cause confusion. Across all languages I use, quotes are generally and almost always used to introduce constant values. Sometimes, maybe, there are macro related things that may use quoting, but as a developer, if I see quotes, I’m thinking: the runtime will treat this as a constant. Having a special case where the quotes are a glorified function call just feels very wrong to me. And likely to be confusing. Steve > - Consistency with the comprehension style for all other iterables > (which seems to be one of the most beloved features of python) > - Confusion surrounding the str.join(iter) syntax is very well > documented > > <https://stackoverflow.com/questions/493819/why-is-it-string-joinlist-instead-of-list-joinstring> > and I believe it is particularly unintuitive when the string is empty > > I also believe the following reasons carry some weight. > > - Skips unnecessary type switching from str to iter and back to str > - Much much MUCH more readable/intuitive > > Please let me know what you all think. It was mentioned (by @rhettinger) > in the PBT issue <https://bugs.python.org/issue43900> that this will > likely require a PEP which I would happily write if there is a positive > response. > > -- > > *David Álvarez Lombardi* > Machine Learning Spanish Linguist > Amazon | Natural Language Understanding > Boston, Massachusetts > alvarezdqal <https://www.linkedin.com/in/alvarezdqal/> > _______________________________________________ > 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/MVQGP4GGTIWQRJTSY5S6SDYES6JVOOGK/ > Code of Conduct: http://python.org/psf/codeofconduct/ >
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