On 09/10/11 23:41, D. Guandalino wrote:
Hi, in this class many methods share common code.
class Foo(object):
def m1(self):
if self.foo:
pass # m1 do something
elif self.bar:
pass # m1 do something else
else:
pass # m1 do something different
def m2(self):
if self.foo:
pass # m2 do something
elif self.bar:
pass # m2 do something else
else:
pass # m2 do something different
# def m_n(self):
pass # same conditionals, different implementation
I'm wondering if I have to duplicate the if/elif/else for each method.
Does Python 2.7 provide a way to factor out this common structure?
Refactoring does not depend on the language so yes you can refactor this
code in 2.7 as well as you can in any other language, but...
Should you?
We can't tell from the code you have posted because you have commented
out the bits that matter - what the methods actually do.
Just because they have the same set of conditional tests does not mean
you should refactor (except maybe at the class level - maybe you need to
split the class into one with foo true and the other with bar true (and
maybe a third for the else...) but never rush to create subclasses
because that brings its own problems!). At the method level refactoring
would depend on the content of the implementation sections. If the two
methods did similar things within those code blocks then you might
introduce new helper methods or parameterise the two methods into one.
But without any idea of the implementation we really can't say.
For example, if m1 creates formatted output for reporting purposes and
m2 saves the data into a database and m_n serialises the class for
transmission over a network then its unlikely that there is much
opportunity to refactor the methods. But it is likely that all three
share the kind of structure you show above.
But if the three methods represent three different styles of report
formatting then yes, we probably can do something.
HTH
--
Alan G
Author of the Learn to Program web site
http://www.alan-g.me.uk/
_______________________________________________
Tutor maillist - Tutor@python.org
To unsubscribe or change subscription options:
http://mail.python.org/mailman/listinfo/tutor
