2009/10/20 Hendrik van Rooyen <hend...@microcorp.co.za>: > So if you want to sum stuff where there are a lot of keys, but only a few > values per key - say between one and ten, then it would be faster to look > before you leap. > > On the other hand, if there are relatively few keys and tens or hundreds of > values per key, then you ask for forgiveness. > > And if you don't know what the data is going to look like, then you should > either go into a catatonic state, or take to the bottle, as the zen of python > states that you should refuse the temptation to guess.
Might I respectfully suggest that in *all* cases you do whatever is *clearest*, then switch to the other one if and only if performance is unacceptable *and* profiling reveals this to be the bottleneck? That avoids your deadlock (or is it livelock?) state. -- Tim Rowe -- http://mail.python.org/mailman/listinfo/python-list