Automated with 2to3 and custom fixer. 2to3 -f print tornado > print.diff 2to3 -f print -d tornado > print_doctest.diff maint/scripts/run_fixers.py -f future_import tornado > future.diff cd tornado git apply ../{print,print_doctest,future}.diff
All existing uses of division were already using a float for at least one operand (except the tests that just do 1/0 as a quick way to throw an exception). We have now turned on all the __future__ options available in python2.5.