KM
это же разные проверки, нет?
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!
