On Fri, Jul 6, 2018 at 12:26 PM, Franklin? Lee I use this kind of function in several different projects over the > > years, and I rewrote it many times as needed. >
> I added several options, such as: > - key function > - value function > - "ignore": Skip values with these keys. > - "postprocess": Apply a function to each group after completion. > - Pass in the container to store in. For example, create an > OrderedDict and pass it in. It may already hold items. > - Specify the container for each group. > - Specify how to add to the container for each group. > interesting... > Then I cut it down to two optional parameters: > - key function. If not provided, the iterable is considered to have > key-value pairs. > OK -- seems we're all converging on that :-) > - The storage container. > so this means you'r passing in a full set of storage containers? I'm a vit confused by that -- if they might be pre-populated, then they would need to be instance,s an you'd need to have one for every key -- how would you know in advance aht you needed??? I played around with passing in a optional storage object: https://github.com/PythonCHB/grouper/commit/d986816905406ec402724beaed2b88c96df64469 but as we might want a list or a set, or a Counter, or ??? it got pretty ugly, as lists and sets and Counters all have different APIs for adding stuff. So I gave up and figured just saying "it's always a list) made the most sense. > Finally, I removed the key function, and only took pairs and an > optional container. However, I don't remember why I removed the key > function. It may be that I was writing throwaway lambdas, and I > decided I might as well just write the transformation into the > comprehension. exactly -- but I suspect hat may be because you where writing a comprehension anyway, as you needed to manipulate the values, also -- so if there were a value function, you could use either API. > I think a key function is worth having. > I think there's more or less consensus on that too. -CHB -- 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
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