On Oct 7, 2019, at 21:21, Caleb Donovick <donov...@cs.stanford.edu> wrote:
> 
> >  But what if you wanted to take both positional AND keyword?
> 
> I was suggesting that that wouldn't be allowed.  So subscript either has a 
> single argument, a tuple of arguments, or a dictionary of arguments.  
> Allowing both has some advantages but is less cleanly integratible. 

The problem is that half the examples people conjure up involve both: using the 
keywords as options, while using the positional arguments for the actual 
indices. Calling the proposal “kwargs in getitem” encourages that thinking, 
because that’s the prototypical reason for kwargs in function calls.

If there were non-toy examples, so people didn’t have to imagine how it would 
be used for themselves, that might be helpful. Why is `d[x=1]` useful but `d[1, 
flag=True]` not needed? If you showed real Pandas queries or whatever instead 
of toy ones, it might be clearer. And you could challenge people who want flags 
to give real examples that you could then dissect.

Also, an actual __get/set/delitem__ implementation using the proposed feature 
would help. You can argue that dealing with the dicts-are-iterable issue won’t 
be a problem in practice, but just showing methods that deal with it and remain 
perfectly readable makes the case a lot better.
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