Mon, 02 Nov 2015 23:37:14 +0800 help: replace some str.split() calls by str.partition() or str.rpartition()
Anton Shestakov <av6@dwimlabs.net> [Mon, 02 Nov 2015 23:37:14 +0800] rev 26845
help: replace some str.split() calls by str.partition() or str.rpartition() Since Python 2.5 str has new methods: partition and rpartition. They are more specialized than the usual split and rsplit, and they sometimes convey the intent of code better and also are a bit faster (faster than split/rsplit with maxsplit specified). Let's use them in appropriate places for a small speedup. Example performance (partition): $ python -m timeit 'assert "apple|orange|banana".split("|")[0] == "apple"' 1000000 loops, best of 3: 0.376 usec per loop $ python -m timeit 'assert "apple|orange|banana".split("|", 1)[0] == "apple"' 1000000 loops, best of 3: 0.327 usec per loop $ python -m timeit 'assert "apple|orange|banana".partition("|")[0] == "apple"' 1000000 loops, best of 3: 0.214 usec per loop Example performance (rpartition): $ python -m timeit 'assert "apple|orange|banana".rsplit("|")[-1] == "banana"' 1000000 loops, best of 3: 0.372 usec per loop $ python -m timeit 'assert "apple|orange|banana".rsplit("|", 1)[-1] == "banana"' 1000000 loops, best of 3: 0.332 usec per loop $ python -m timeit 'assert "apple|orange|banana".rpartition("|")[-1] == "banana"' 1000000 loops, best of 3: 0.219 usec per loop
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