Chris Angelico writes: > Memoization can only be done for pure functions.
True, but when for impure f you naively construct a list [f(x), f(x)], substituting [(f(x) as wrong), wrong] is just [wrong, wrong] ;-), because the side effect doesn't get reevaluated. Steve _______________________________________________ Python-ideas mailing list Python-ideas@python.org https://mail.python.org/mailman/listinfo/python-ideas Code of Conduct: http://python.org/psf/codeofconduct/
