Using s.sort([cmp[, key[, reverse]]]) to sort a list of objects based on a attribute
Alex Martelli
aleax at mac.com
Sun Sep 9 11:59:08 EDT 2007
Stefan Arentz <stefan.arentz at gmail.com> wrote:
> Miki <miki.tebeka at gmail.com> writes:
>
> > > steps.sort(key = lambda s: s.time)
> > This is why attrgetter in the operator module was invented.
> > from operator import attrgetter
> > ...
> > steps.sort(key=attrgettr("time"))
>
> Personally I prefer the anonymous function over attrgettr :)
However, Python disagrees with you...:
brain:~ alex$ python -mtimeit -s'from operator import attrgetter;
L=map(complex,xrange(999))' 'sorted(L, key=lambda x:x.real)'
1000 loops, best of 3: 567 usec per loop
brain:~ alex$ python -mtimeit -s'from operator import attrgetter;
L=map(complex,xrange(999))' 'sorted(L, key=attrgetter("real"))'
1000 loops, best of 3: 367 usec per loop
A speed-up of 35% is a pretty clear indicator of what _Python_ "prefers"
in this situation:-).
Alex
More information about the Python-list
mailing list