Peter Otten wrote:
> Daishi Harada wrote:
>
>
>>I'd like to get the 'get2' function below to
>>perform like the 'get1' function (I've included
>>timeit.py results).
>
>
>
>>labels = ('a', 'b')
>>def get1(x):
>> return (x.a, x.b)
>>def mkget(attrs):
>> def getter(x):
>> return tuple(getattr(x, label) for label in attrs)
>> return getter
>>get2 = mkget(labels)
>>
>># % timeit.py -s "import test" "test.get1(test.a)"
>># 1000000 loops, best of 3: 0.966 usec per loop
>># % timeit.py -s "import test" "test.get2(test.a)"
>># 100000 loops, best of 3: 4.46 usec per loop
>
> No, you can just sit back and wait -- for Python 2.5:
>
> $ cat attr_tuple25.py
> import operator
>
> class A:
> a = 1
> b = 2
>
> get2 = operator.attrgetter("a", "b")
>
> def get1(x):
> return x.a, x.b
>
> $ python2.5 -m timeit -s'from attr_tuple25 import A, get1, get2' 'get1(A)'
> 1000000 loops, best of 3: 0.813 usec per loop
> $ python2.5 -m timeit -s'from attr_tuple25 import A, get1, get2' 'get2(A)'
> 1000000 loops, best of 3: 0.495 usec per loop
With Python 2.4 you can at least get closer to the hardcoded version:
F:\>type attr_tuple.py
import operator
class A:
a = 1
b = 2
getA = operator.attrgetter("a")
getB = operator.attrgetter("b")
def get2(x):
return getA(x), getB(x)
def get1(x):
return x.a, x.b
F:\>python -m timeit -s"from attr_tuple import A, get1, get2" "get1(A)"
1000000 loops, best of 3: 0.658 usec per loop
F:\>python -m timeit -s"from attr_tuple import A, get1, get2" "get2(A)"
1000000 loops, best of 3: 1.04 usec per loop
Kent
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