James Newton wrote: > Hi Python Purists! > > I want all instances of a given class to share a piece of information, > but I want to set that information on the fly. I have found that this > works: > > > class Foo(object): > # class_variable = None # There is no real need to declare this > > def __init__(self): > print self.__class__.class_variable
could be just self.class_variable, attributes are looked up in the class if not found in the instance (that's how method access works, e.g.). > def main(): > Foo.class_variable = "Done" > Foo() > > > if __name__ == '__main__': main() > > > Running the script prints out "Done" as expected. > > However, this looks ugly to me. Is there a more elegant way of doing > this? Seems OK to me. > To give you the context: my application allows you to select a skin for > the user interface. I want to set the access path to the skin folder as > a class variable, so that all instances of that class use images from > the appropriate folder. The access path will be read in from a > preferences file before any instances of the class are created. Why do you have multiple instances of the class? You might be interested in the Borg pattern: http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/66531 Kent _______________________________________________ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
