I think C# calls methods that are added to a class "extension methods". You can make a decorator that will do that for you:
> def extend(cls): > """ > DECORATOR TO ADD METHODS TO CLASSES > :param cls: THE CLASS TO ADD THE METHOD TO > :return: > """ > def extender(func): > setattr(cls, get_function_name(func), func) > return func > return extender and use it > C = MyClass > @extend(C) > def foo(self, schesome_param): > some_code() On 2018-07-30 14:12, Chris Barker via Python-ideas wrote: > On Mon, Jul 30, 2018 at 9:10 AM, Nick Coghlan <ncogh...@gmail.com > <mailto:ncogh...@gmail.com>> wrote: > > If you need to replace them for some reason, it will preferably be > within a temporary bounded scope, using a tool like > unittest.mock.patch, rather than as a permanent change that affects > every other use of the class within the process. > > > yup -- but you can still do a raw monkey-patch anyway. You asked for: > > > Thank you for your question. You asked why not > >> c = MyClass > >> o = c() > >> > >> def c.foo(cls): ... > > > do you mean this? you want a classmethod? or is this what you mean? -- > which you can do: > > C = MyClass > > def foo(self, some_param): > some_code() > > C.foo = foo > > (note that I used a capital C -- capitalized names are traditional for > classes -- see PEP 8) > > In that case, any existing, and new instances of the C class will now > have the foo method. > > Also -- that line: C = MyClass -- binds the name "C" to the very same > class object as MyClass -- so you will have just monkey=patched > MyClass -- I"m guessing you didn't want that. If not, and you wanted C > t be a copy of MyClass that you could then change/add/remove methods > from, then you want subclassing -- that is exactly what it is for. > > Then there is this: > > > >> def o.bar(self): ... > > > which is monkey patching an instance object, which you can also do, > but you don't get a bound method -- i.e. it doesn't get self passed in > automatically. > > -CHB > > > > > > > > > > > > > I've the same same query, but never had the courage to ask. So that > > you for asking. And also giving me a chance to share my thoughts. > > It's essentially due to the fact that while we deliberately allow > runtime monkeypatching (as it's sometimes the best available answer), > we also strongly encourage the idea of treating it as a last resort > option (outside specific use cases like testing). > > So if you want to define methods on a class, the strongly preferred > place to define them is inside the class definition, where they're > easy for future maintainers of that class to find. > > > Cheers, > Nick. > > P.S. While it's *not* explicitly part of Python's design rationale, > http://connascence.io/locality.html > <http://connascence.io/locality.html> and the rest of that site > provide > some good info on the kinds of problems that "action at a distance" > effects, like monkeypatching class definitions, can cause in a code > base. > > -- > Nick Coghlan | ncogh...@gmail.com <mailto:ncogh...@gmail.com> > | Brisbane, Australia > _______________________________________________ > Python-ideas mailing list > Python-ideas@python.org <mailto:Python-ideas@python.org> > https://mail.python.org/mailman/listinfo/python-ideas > <https://mail.python.org/mailman/listinfo/python-ideas> > Code of Conduct: http://python.org/psf/codeofconduct/ > <http://python.org/psf/codeofconduct/> > > > > > -- > > Christopher Barker, Ph.D. > Oceanographer > > Emergency Response Division > NOAA/NOS/OR&R (206) 526-6959 voice > 7600 Sand Point Way NE (206) 526-6329 fax > Seattle, WA 98115 (206) 526-6317 main reception > > chris.bar...@noaa.gov <mailto:chris.bar...@noaa.gov> > > > _______________________________________________ > Python-ideas mailing list > Python-ideas@python.org > https://mail.python.org/mailman/listinfo/python-ideas > Code of Conduct: http://python.org/psf/codeofconduct/
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