On 2007-01-13, Steven D'Aprano <[EMAIL PROTECTED]> wrote:
> I'm writing a class that implements rich comparisons, and I find myself
> writing a lot of very similar code. If the calculation is short and
> simple, I do something like this:
>
>
> class Parrot:
> def __eq__(self, other):
> return self.plumage() == other.plumage()
> def __ne__(self, other):
> return self.plumage() != other.plumage()
> def __lt__(self, other):
> return self.plumage() < other.plumage()
> def __gt__(self, other):
> return self.plumage() > other.plumage()
> def __le__(self, other):
> return self.plumage() <= other.plumage()
> def __ge__(self, other):
> return self.plumage() >= other.plumage()
Well one thing you could do is write the following class:
Comparators = SomeEnumWith("eq, ne, lt, gt, ge, le, ge")
class GeneralComparator:
def __eq__(self, other):
return Comparators.eq in self.__compare__(self, other)
def __ne__(self, other):
return Comparators.ne in self.__compare__(self, other)
def __lt__(self, other):
return Comparators.lt in self.__compare__(self, other)
def __le__(self, other):
return Comparators.le in self.__compare__(self, other)
def __gt__(self, other):
return Comparators.gt in self.__compare__(self, other)
def __ge__(self, other):
return Comparators.ge in self.__compare__(self, other)
Then write your Parrot class as follows:
class Parrot (GeneralComparator):
def __compare__(self, other):
return a set which defines which comparisons should return true.
--
Antoon Pardon
--
http://mail.python.org/mailman/listinfo/python-list
