On Fri, 22 Sep 2017 21:15:54 +1000, Steve D'Aprano wrote: > On Fri, 22 Sep 2017 08:50 pm, alister wrote: > >>> The bottom line is, if I saw >>> >>> if not (thing > 0): raise AssertionError(...) >>> >>> in a code review, I'd probably insist that either it be changed to use >>> `assert`, >>> or the exception be changed to ValueError, whichever better expresses >>> the intention of the code. >> >> In a code review I would want the condition changed to be less noisy/ >> confusing to the reader. >> >> if thing <=0: whatever > > Fair point, assuming they are the same. > > Actually, even for floats they're not the same. > > py> not (NAN > 0) > True py> NAN <= 0 False
I bet those are conditions the original author did not expect actually I am not sure how you got them on my system python 2.7 >>> not (NAN >0) Traceback (most recent call last): File "<stdin>", line 1, in <module> NameError: name 'NAN' is not defined >>> NAN <=0 Traceback (most recent call last): File "<stdin>", line 1, in <module> NameError: name 'NAN' is not defined Python 3 Python 3.6.2 (default, Aug 11 2017, 11:59:59) [GCC 7.1.1 20170622 (Red Hat 7.1.1-3)] on linux Type "help", "copyright", "credits" or "license" for more information. >>> not (NAN > 0) Traceback (most recent call last): File "<stdin>", line 1, in <module> NameError: name 'NAN' is not defined >>> NAN <= 0 Traceback (most recent call last): File "<stdin>", line 1, in <module> NameError: name 'NAN' is not defined I would also say that if your examples did indeed return different results then pythons logic model has a bug. -- Say "twenty-three-skiddoo" to logout. -- https://mail.python.org/mailman/listinfo/python-list
