questions about programming styles

[Michael Hoffman]

fdu.xiaojf at gmail.com wrote:

> (1)
> which is the better way to calculate the value of attributes of a class ?
> for example:
> 
> (A)
>    def cal_attr(self, args):
>        #do some calculations
>        self.attr = calculated_value
> and then if the vlue of attribute is needed,
>    self.cal_attr(args)
>    some_var = self.attr
> or I can define cal_attr() as follows:
> (B)
>    def cal_attr(self, args):
>        #do some calculations
>        return calculated_value
> and then, if the value of attribute is needed,
>    self.attr = self.cal_attr(args)
>    some_var = self.attr

In many cases (I would really have to see the context to be sure) would 
prefer something like:

def get_attr(self, args):
     # calculations here
     return calculated_value

Don't have a self.attr, just return the results of get_attr().
-- 
Michael Hoffman