Requiring a Python class property to be explicitly set in its subclasses

required_subclass_property.py

# Base class
In [1]: class Foo(object):
   ...:     @property
   ...:     def bar(self):
   ...:         raise NotImplementedError
   ...:     

# Subclass 1, with property explicitly set
In [2]: class Foof(Foo):
   ...:     bar = "taco"
   ...:     

# Subclass 2, without property explicitly set
In [3]: class Foofer(Foo):
   ...:     pass
   ...: 

# Subclass 1 works as intended
In [4]: f = Foof()

In [5]: f.bar
Out[5]: 'taco'

# Subclass 2 borks
In [6]: f = Foofer()

In [7]: f.bar
---------------------------------------------------------------------------
NotImplementedError                       Traceback (most recent call last)
<ipython-input-7-9980d487a7ee> in <module>()
----> 1 f.bar

<ipython-input-1-511cebe5ae6b> in bar(self)
      2     @property
      3     def bar(self):
----> 4         raise NotImplementedError
      5 

NotImplementedError: