Thanks to all for the comments, It was much more than I expected. Vincent
On Fri, Jun 19, 2009 at 4:30 PM, Lie Ryan<lie.1...@gmail.com> wrote: > Alan Gauld wrote: >> >> "Vincent Davis" <vinc...@vincentdavis.net> wrote >> >> class B(): >> def __init__(self, b1, b2): >> self.fooa = b1 >> self.foob = b2 >> >> I assume thats what you really meant! >> >> Ok now I have several instances in a list >> b1 = B(1, 2) >> b2 = B(3, 4) >> b3 = B(9, 10) >> alist = [b1, b2, b3] >> >>> Lets say for each instance of the class I want to print the value of >>> fooa if it is greater than 5. How do I do this, >> >> define a method of the class, say bigprint() >> >> def bigprint(self, limit=5): >> if self.fooa > limit: print self.fooa >> >>> about is how I iterate over the values of fooa. >> >> Iterate over the objects and call the method. Make the object do the >> work, your code should not need to know about the internal attributes of >> the object. >> >> For x in alist: >> x.bigprint() >> >>> Is that the right way or is there a better? >>> will this work for methods? >> >> Methods are how you should do it. Direct access other than for simple >> reading of values is a suspicious design smell. Any processing of or >> rules about the data should be in a method. >> >> > > Personally, I often thought input/output inside an object is a design > smell (except for debugging), preferring something like this: > > class B(object): > def __init__(...): > ... > def big(self, limit=5): > return (self.fooa > limit) > > alist = [...] > > for y in (x for x in alist if x.big()): > print y.fooa > > although admittably often it could make certain codes more difficult to > write; and in some cases the practical approach would be warranted. This > is especially true as the codebase gets larger. > > _______________________________________________ > Tutor maillist - tu...@python.org > http://mail.python.org/mailman/listinfo/tutor > _______________________________________________ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
