I'm not sure if I'd say that it's the Python community that has encouraged that practice. I think it's more likely just a bad habit that some people may have p

I'm not sure if I'd say that it's the Python community that has encouraged that practice. I think it's more likely just a bad habit that some people may have picked up when using PHP or JavaScript, and mistakenly continued using after moving to Python. PEP 8 (http://legacy.python.org/dev/peps/pep-0008/#programming-recommendations http://legacy.python.org/dev/peps/pep-0008/#programming-reco...) is quite clear about this: "Comparisons to singletons like None should always be done with is or is not, never the equality operators. Also, beware of writing if x when you really mean if x is not None -- e.g. when testing whether a variable or argument that defaults to None was set to some other value. The other value might have a type (such as a container) that could be false in a boolean context!" PEP 8 is more representative of the actual Python community's views than the mistakes of some programmers who are more accustomed to certain languages that are not Python.