Trinary operator?

[Andrew Dalke]

Dale Strickland-Clark:
>But several orders of magnitude more processing [to use a dictionary
>compared to an and/or solution]. Certainly not for tight, efficient loops.

Perhaps your intuition comes from C?  That doesn't seem to be the
case for Python.

>>> def do_filter1(data):
...     for x in data:
...             v = x == 'm' and 'male' or 'female'
...
>>> def do_filter2(data):
...     d = {"m": "male", "f": "female"}
...     for x in data:
...             v = d[x]
...
>>> def test_size(n):
...     data = ["m", "f"] * n
...     t1 = time.clock()
...     do_filter1(data)
...     t2 = time.clock()
...     do_filter2(data)
...     t3 = time.clock()
...     print "and/or", t2-t1, "dict", t3-t2, "ratio", (t2-t1)/(t3-t2)
...
>>> import time
>>> test_size(10000)
and/or 0.04392 dict 0.02928 ratio 1.5
>>> test_size(100000)
and/or 0.437248 dict 0.298656 ratio 1.46405228758
>>> test_size(1000000)
and/or 4.379312 dict 3.004128 ratio 1.45776478233
>>>

Dictionary looks faster to me, in this small, tight loop.

                    Andrew
                    dalke at dalkescientific.com