Mandatory overriding of fields/methods?

Question

How do you specify in a Python parent class that certain fields/methods need to be overridden in the child classes?

Possible duplicate of http://stackoverflow.com/questions/1151212/equivalent-of-notimplementederror-for-fields-in-python — LSerni, Feb 05 '13 at 09:46

score 6 · Accepted Answer · answered Feb 05 '13 at 09:44

6

You could raise a NotImplementedError:

def my_method(self, arg):
    raise NotImplementedError('Implement me')

For properties, you can use the @property decorator:

@property
def my_property(self):
    raise NotImplementedError('Implement me as well')

answered Feb 05 '13 at 09:44

Blender

Yes, that should take care of a method, but what about fields? – Al Bundy Feb 05 '13 at 09:45

score 1 · Answer 2 · answered Feb 05 '13 at 09:46

1

You could look at the abstract base class module.

However, a simpler alternative is just to define a stub implementation that does nothing, or raises NotImplementedError.

answered Feb 05 '13 at 09:46

BrenBarn

2 Answers2