I've pretty much always taught using the "comprehension" term. It makes sense to introduce comprehensions on concrete collections first. Then I typically say something like "This special kind of comprehension is called a 'generator expression'". Usually that's accompanied by a motivation like creating a listcomp of a hundred million items, then showing that creating the generator expression is instantaneous.
However, after the initial introduction, I consistently call it a generator expression. Albeit, for the students I teach—data scientists and quants, mostly—there's not a lot of time spent on that being the introduction (by then I'm talking about NumPy and Pandas, and scikit-learn, and Seaborn, abd Statsmodels, and so on. If things are "lazy" it's because they are Dask deferred or Dask DataFrame. On Sun, Jul 15, 2018, 1:02 PM Chris Barker via Python-Dev < python-dev@python.org> wrote: > Thanks Nick, > > I'll adopt this approach when I update my teaching materials. > > If I think of it, I"ll post here when I do that > > -CHB > > > On Sun, Jul 15, 2018 at 12:21 AM, Nick Coghlan <ncogh...@gmail.com> wrote: > >> On 13 July 2018 at 15:30, Chris Barker via Python-Dev >> <python-dev@python.org> wrote: >> > On Mon, Jul 9, 2018 at 3:18 PM, Guido van Rossum <gu...@python.org> >> wrote: >> >> >> >> Definitely docs first. And we should keep references to generator >> >> expressions too, if only to explain that they've been renamed. >> >> >> >> Perhaps someone should try it out in a 3rd party tutorial to see how it >> >> goes? >> > >> > >> > I'm not sure what "trying it out in a tutorial" would look like. >> > >> > I try to be pretty clear about terminology when I teach newbies -- so I >> > don't want to tell anyone this new thing is called a "generator >> > comprehension" if they aren't going to see that term anywhere else. >> >> Nina Zakharenko made the "they're officially called generator >> expressions, but I find it more helpful to think of them as generator >> comprehensions" observation in her PyCon 2018 presentation on "Elegant >> Solutions for Everyday Python Problems": >> >> https://www.slideshare.net/nnja/elegant-solutions-for-everyday-python-problems-pycon-2018/27 >> >> The article from Ned Batchelder mentioned in that slide is this one, >> which goes through the history of Raymond originally proposing the >> notion as generator comprehensions, them getting changed to generator >> expressions during the PEP 289 discussions, and then asking if it >> might be worth going back to the originally suggested name: >> https://nedbatchelder.com/blog/201605/generator_comprehensions.html >> >> And then in PEP 572, it was found that being able to group all 4 >> constructs (list/set/dict comps + generator expressions) under a >> single term was a genuinely useful shorthand: >> https://www.python.org/dev/peps/pep-0572/#scope-of-the-target >> >> So trying out the terminology in a tutorial context would be to do >> something similar to what Nina did in her talk: introduce the notion >> of list/set/dict/generator comprehensions, and then make a side note >> that the latter are officially referred to as "generator expressions". >> >> This wouldn't be the first time that terminology has differed between >> Python-as-commonly-taught and Python-as-formally-defined, as I've yet >> to hear anyone refer to container displays outside a language design >> discussion - everyone else calls them container literals (or, more >> typically, a literal for the specific builtin container type being >> discussed). >> >> In this case, though, we'd be considering eventually changing the >> language reference as well, and perhaps even some day the AST node >> name (from GeneratorExp to GeneratorComp). >> >> We wouldn't need to change anything in the grammar definition (since >> that already shares the comp_for and comp_if syntax definitions >> between container comprehensions and generator expressions), or the >> AST node structure (since GeneratorExp already uses a "comprehensions" >> attribute, the same as the ListComp/SetComp/DictComp nodes). >> >> Cheers, >> Nick. >> >> -- >> Nick Coghlan | ncogh...@gmail.com | Brisbane, Australia >> > > > > -- > > Christopher Barker, Ph.D. > Oceanographer > > Emergency Response Division > NOAA/NOS/OR&R (206) 526-6959 voice > 7600 Sand Point Way NE (206) 526-6329 fax > Seattle, WA 98115 (206) 526-6317 main reception > > chris.bar...@noaa.gov > _______________________________________________ > Python-Dev mailing list > Python-Dev@python.org > https://mail.python.org/mailman/listinfo/python-dev > Unsubscribe: > https://mail.python.org/mailman/options/python-dev/mertz%40gnosis.cx >
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