negative "counts" in collections.Counter?

Vlastimil Brom vlastimil.brom at gmail.com
Mon Mar 8 23:24:43 CET 2010


2010/3/8 Raymond Hettinger <python at rcn.com>:
...
[snip detailed explanations]
>...
> In this case, we have an indication that what you really want is
> a separate class supporting elementwise binary and unary operations
> on vectors (where the vector fields are accessed by a dictionary
> key instead of a positional value).
>
>
>> Additionally, were issubset and issuperset considered for this
>> interface (not sure whether symmetric_difference would be applicable)?
>
> If the need arises, these could be included.  Right now, you
> can get the same result with:  "if a - b: ..."
>
> FWIW, I never liked those two method names.  Can't remember whether
> a.issubset(b) means "a is a subset of b" or "b issubset of a'.
>
>
> Raymond
> --
>
Thanks for the further remarks Raymond,
initially I thought while investigating new features of python 3, this
would be a case for replacing the "home made" solutions with the
standard module functionality.
Now I can see, it probably wouldn't be an appropriate decision in this
case, as the expected usage of Counter with its native methods is
different.

As for the issubset, issuperset method names, I am glad, a far more
skilled person has the same problem like me :-)   In this case the
operators appear to be clearer than the method names...

regards,
   vbr



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