I have a base class with a property which (the get method) I want to overwrite in the subclass. My first thought was something like:
class Foo(object):
def _get_age(self):
return 11
age = property(_get_age)
class Bar(Foo):
def _get_age(self):
return 44
This does not work (subclass bar.age returns 11). I found a solution with an lambda expression which works:
age = property(lambda self: self._get_age())
So is this the right solution for using properties and overwrite them in a subclass, or are there other preferred ways to do this?
I simply prefer to repeat the property()
as well as you will repeat the @classmethod
decorator when overriding a class method.
While this seems very verbose, at least for Python standards, you may notice:
1) for read only properties, property
can be used as a decorator:
class Foo(object):
@property
def age(self):
return 11
class Bar(Foo):
@property
def age(self):
return 44
2) in Python 2.6, properties grew a pair of methods setter
and deleter
which can be used to apply to general properties the shortcut already available for read-only ones:
class C(object):
@property
def x(self):
return self._x
@x.setter
def x(self, value):
self._x = value