2016-08-09 14:01 GMT-07:00 Michael Selik <michael.se...@gmail.com>: > On Tue, Aug 9, 2016 at 3:22 PM Juan Pablo Romero Méndez < > jpablo.rom...@gmail.com> wrote: > >> I'm actually looking for ways to minimize run time errors, so that would >> include TypeError and AttributeError. >> >> In your "File-like" example having type information would prevent me from >> even passing the wrong object, so I don't need to test for that particular >> problem. >> > > Let's clarify this discussion by using the word "check" for type-checks > that necessary for the application to behave as desired and using the word > "test" for checking application behavior under normal and edge cases, such > as unexpected types being passed. > > Are you saying you want to minimize type-checks during the execution of > your application? Or do you want to minimize the amount of testing code you > write? >
My goal is determine if there is a style of writing code in a dynamic language that minimizes the occurrence of runtime errors AND avoids two things: 1) using runtime checks all over the place (either ad hoc or using tools like Valideer) 2) attempting to test for things that a type checker would normally do (not that this is completely possible anyway) (I'm not suggesting I want to avoid writing tests at all, since there are many things the type checker can't possible check). > > I don't check for file-likeness in the application code. If somehow a > non-file-like (file-unlike?) object makes its way into my function, I > expect (and hope) my program will immediately stop and print a nice > traceback for me. If I wanted some other behavior, I probably would already > have try/except surrounding the appropriate section to deal with not-found > or permissions errors. If I need to, I'll add TypeError and AttributeError > to that except statement. > > This is interesting. You are Ok having runtime errors? > I sometimes write tests for unexpected inputs, checking to ensure that > either a TypeError or AttributeError is raised. However, sometimes I'm not > worried about it. If the user gives me bizarre input, they should know to > expect (possibly) bizarre results. Who knows, maybe that's what they wanted. > > I would add type-checking or value-checking to my application if the > wrong type or value does not raise an error but instead causes an infinite > loop or corrupts data. Those situations are fairly rare. > > > > On Tue, Aug 9, 2016 at 4:52 PM Juan Pablo Romero Méndez < > jpablo.rom...@gmail.com> wrote: > >> So as the writer of the function you expect the user to read the function >> body to determine what is safe to pass or not? > > > No. But I usually expect them to not freak out when they see a traceback. > Or if they do freak out, I want them to freak out and send a bug report. > -- https://mail.python.org/mailman/listinfo/python-list
