I'm writing a small piece of code in Python and am curious what other people think of this.
I have a few classes, each with a few methods, and am trying to determine what is "better": to pass objects through method calls, or to pass methods through method calls when only one method from an object is needed. Basically, should I do this:
def do_something(self, x, y, manipulator):
self.my_value = manipulator.process(x, y)
or this
def do_the_same_thing_but_differently(self, x, y, manipulation):开发者_JS百科
self.my_value = manipulation(x, y)
The way I see it, the second one is arguably "better" because it promotes even looser coupling/stronger cohesion between the manipulation and the other class. I'm curious to see some arguments for and against this approach for cases when only a single method is needed from an object.
EDIT: I removed the OOP wording because it was clearly upsetting. I was mostly referring to loose coupling and high cohesion.
The second solution may provide looser coupling because it is more "functional", not more "OOP". The first solution has the advantage that it works in languages like C++ which don't have closures (though one can get a similar effect using templates and pointer-to-member-functions); but in a language like Python, IMHO the 2nd alternative seems to be more "natural".
EDIT: you will find a very nice discussion of "functional vs. object oriented" techniques in the free book "Higher order Perl", available here:
http://hop.perl.plover.com/
(look into chapter 1, part 6). Though it is a Perl (and not a Python) book, the discussion there fits exactly to the question asked here, and the functional techniques described there can be applied to Python in a similar way.
I will say the second approach ; because it's definitely look like a callback which they are very used when using the Hollywood principle (don't call us we will call you) which is a paradigm that assists in the development of code with high cohesion and low coupling [Ref 2] .
I would definitely go with the second approach.
Also consider that you could change the interface of whatever Manipulator class so that process
is instead spelled __call__
, and then it will work transparently with the second approach.
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