> I have seen at several places "x == None" and "x is None" within > if-statements. > What is the difference? > Which term should I prefer and why? > > > -- > Ullrich Horlacher Server und Virtualisierung > Rechenzentrum IZUS/TIK E-Mail: horlac...@tik.uni-stuttgart.de > Universitaet Stuttgart Tel: ++49-711-68565868 > Allmandring 30a Fax: ++49-711-682357 > 70550 Stuttgart (Germany) WWW: http://www.tik.uni-stuttgart.de/
In this case, the Style Guide for Python Code [1] recommends use "is or is not, never the equality operators" [2]. If you use the pep8 tool [3] to check your code, the error code that will be raised is E711 [4]. [1] https://www.python.org/dev/peps/pep-0008/ [2] https://www.python.org/dev/peps/pep-0008/#programming-recommendations [3] http://pep8.readthedocs.org/en/latest/intro.html [4] http://pep8.readthedocs.org/en/latest/intro.html#error-codes -- https://mail.python.org/mailman/listinfo/python-list
