On Nov 26, 6:08 pm, Jean-Michel Pichavant <jeanmic...@sequans.com> wrote: > Peng Yu wrote: > > There are some assertion code (testing if a condition is false, if it > > is false, raise an Error object) in my python, which is useful when I > > test my package. But such case would never occur when in the produce > > code. If I keep them in if statement, it will take some runtime. I'm > > wondering what is the practice that take care of the assertion code in > > python. > > Would never occur ? You can't use 'would' and 'never' in the same > sentence. That is the kind of concect that make (to me) asserts diffcult > to use. > I personally never use asserts in python, cause I will end up handling > with asserts what I should in fact handle properly in what you call the > production code. > > Anyway that does not answer your question I'm sorry to be off topic, > 'tis just a thought. Simon gave you the proper answer. > > Jean-Michel
I can see this issue has several facets to it, so I don't intend to flagratly contradict your experience Jean-Michel, but I think that in at least some circumstances asserts used in this way can be valuable. One of the interesting points to come out of the recent flurry of empirical studies of software engineering is that quality of code as measured by defect density shows a definite negative correllation with use of asserts in production code. (Although the significance of this is somewhat lessened by the fact that both use of asserts and low defect density are correlated with the level of developer experience.) Original Microsoft paper here: http://research.microsoft.com/apps/pubs/default.aspx?id=70290 Summary article discussing that paper and others: http://research.microsoft.com/en-us/news/features/nagappan-100609.aspx Personally, I'm curious as to whether the benefit from asserts used in this way is in helping the developer to clarify in their own mind exactly what their expectations and invariants are. -- http://mail.python.org/mailman/listinfo/python-list
