Raymond Hettinger wrote:
>> should the repr for a set be set({a, b, c})
>> instead of set([a, b, c])?
>
> FWIW, running eval() on the repr is slower and less memory efficient with
> curly braces than with the square brackets.
This is what I get.
>>> timeit.timeit("eval('frozenset({1,2,3})')")
48.011682987213135
>>> timeit.timeit("eval('frozenset([1,2,3])')")
48.155133962631226
>>> timeit.timeit("eval('frozenset((1,2,3))')")
48.062387943267822
>>> timeit.timeit("eval('set({1,2,3})')")
46.738940000534058
>>> timeit.timeit("eval('set([1,2,3])')")
47.597666025161743
>>> timeit.timeit("eval('set((1,2,3))')")
47.087898969650269
It's all very close. I think the frozenset({1,2,3}) example will get
faster if {..} notation becomes a frozen set, and set({...}) example will
slow down a bit.
> Also, it may be easily misread as meaning: set([frozenset([a, b, c])]). If
> the latter is intended, then that would become set({{a, b, c}}) which I find
> hard to parse correctly. Maybe the set([a, b, c]) form should live on.
>
> Raymond
You added an extra level of nesting. set(frozenset([a, b, c])) isn't any
harder to parse (to me) than the equivalent tuple or list versions of the
same forms: list(tuple([a, b, c]) and tuple(list([a, b, c]).
Ron
_______________________________________________
Python-3000 mailing list
Python-3000@python.org
http://mail.python.org/mailman/listinfo/python-3000
Unsubscribe:
http://mail.python.org/mailman/options/python-3000/archive%40mail-archive.com
