On Apr 5, 6:50 pm, Ethan Furman <et...@stoneleaf.us> wrote:
(Posted some code with a timeit...)
Well, I'm not going to debug this, but with the *original* thing you
posted, and the thing I posted, with a call and everything (more
realistic scenario), the exception version seems slower on my machine:
#!/usr/bin/env python
import timeit
def frobnicate(a,b,c,d):
pass
def heavy_lifting_at_runtime():
print 'heavy'
class spam_except(object):
def __call__(self, x, y, z):
try:
mongo = self.mongo
except AttributeError:
mongo = self.mongo = heavy_lifting_at_runtime()
return frobnicate(x, y, z, mongo)
se = spam_except()
class spam_if(object):
def __getattr__(self, name):
if name != 'mongo':
raise AttributeError
self.mongo = heavy_lifting_at_runtime()
return self.mongo
def __call__(self, x, y, z):
return frobnicate(x, y, z, self.mongo)
si = spam_if()
tse = timeit.Timer('se(1,2,3)', "from __main__ import se")
tsi = timeit.Timer('si(1,2,3)', "from __main__ import si")
for i in range(5):
ve = tse.timeit(10000000)
vi = tsi.timeit(10000000)
print ve, vi, '%.1f' % ((ve-vi) / vi * 100)
------
heavy
heavy
5.45695090294 5.10844397545 6.8
5.43381404877 5.01345705986 8.4
5.42474508286 5.02641201019 7.9
5.40713405609 5.04178905487 7.2
5.38063693047 4.96194696426 8.4
The output indicates that the exception one is, on average, around
7.5% slower.
Regards,
Pat
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