When a module wants to raise an exception indicating that some functionality is not implemented, the built-in exception type that it wants to use is NotImplementedError, not NotImplemented. Replace NotImplemented with NotImplementedError or else Python will raise a TypeError error at runtime and the module will not not successfully execute.

NotImplemented is a built-in constant used by some Python special methods (such as __eq__ and __lt__) to indicate that a specific type of comparison is not implemented within that special method. NotImplementedError is a standard exception from the Python Standard Library.

The author of the area function below has not finished implementing the function. To ensure that other programmers understand that the function is not yet available, the area function always returns NotImplemented whenever it is called. However, NotImplemented is not a valid object type for raise statements, so Python raises a TypeError whenever area is called.

def area(width, height):
    """TODO: implement me"""
    raise NotImplemented  # causes TypeError

area(2, 4)

The NotImplemented raised, should raise NotImplementedError is suppressed once the author of the function replaces NotImplemented with NotImplementedError.

def area(width, height):
    """TODO: implement me"""
    raise NotImplementedError  # ok now

area(2, 4)

• PyLint - E0711
• Python Standard Library - Built-In Exceptions
• Python Standard Library - Built-In Constants