None object

None means empty object. In Python there is one and only such an object (singleton).

None is used in this cases:

• It is default return value of all functions. So if don't explicitly specify return in the function it will return None.

• Also it used as argument value for passing to a function to mark empty list (or other mutable).

Also, it worth to note that None doesn't have attributes and in boolean operations is being treated as False.