I had a Hadoop map-reduce job that kept timing out, which led to this interesting discovery:
$ time ./json-parser-test.py real 0m0.205s user 0m0.152s sys 0m0.032s $ time ./json-parser-test-no-speedups.py real 0m2.069s user 0m2.044s sys 0m0.024s $ time jython ./json-parser-test-no-speedups.py real 79m59.785s user 80m23.709s sys 0m14.441s
Moral: use Java-based JSON libraries if you have to use Jython and JSON. Also, Java sucks.