On Fri, 17 Jul 2009 11:01:49 +1000, Ben Finney <ben+pyt...@benfinney.id.au>
wrote:
Howdy all,
The following is a common idiom::
class FooGonk(object):
def frobnicate(self):
""" Frobnicate this gonk. """
basic_implementation(self.wobble)
class BarGonk(FooGonk):
def frobnicate(self):
special_implementation(self.warble)
The docstring for ‘FooGonk.frobnicate’ is, intentionally, perfectly
applicable to the ‘BarGonk.frobnicate’ method also. Yet in overriding
the method, the original docstring is not associated with it.
Ideally there would be a way to specify that the docstring should be
inherited. The best I can come up with is::
class BarGonk(FooGonk):
def frobnicate(self):
special_implementation(self.warble)
frobnicate.__doc__ = FooGonk.frobnicate.__doc__
but that violates DRY (the association between BarGonk and FooGonk is
being repeated), puts the docstring assignment awkwardly after the end
of the method instead of at the beginning where docstrings normally go,
and reads poorly besides.
What is the most Pythonic, DRY-adherent, and preferably least-ugly
approach to override a method, but have the same docstring on both
methods?
How about this?
class BarGonk(FooGonk):
@inherit_docstring
def frobnicate(self):
special_implementation(self.warble)
The implementation of "inherit_docstring" is left as an exercise for the
reader (it's not utterly trivial, I admit, as "FooGonk" will not readily
be at hand, but it is still possible).
By the way, I don't think this is a particularly good idea. Presumably
there is a reason your implementation is special. It would probably be
better if this were reflected in the docstring somehow. Perhaps this
idea is a better one:
class BarGonk(FooGonk):
@append_to_docstring
def frobnicate(self):
"""
This implementation takes the warble into consideration.
"""
special_implementation(self.warble)
With the result of BarGonk.frobnicate.__doc__ being set to:
Frobnicate this gonk.
This implementation takes the warble into consideration.
Jean-Paul
--
http://mail.python.org/mailman/listinfo/python-list
