On Apr 2, 10:11 pm, Stephen Hansen <apt.shan...@gmail.invalid> wrote: > > I don't know if properties are really faster or slower then a > __getattr__, but I find them a lot cleaner if I want to delay some > calculation until needed like that.
Well, the relative speed of properties vs. __getattr__ can become irrelevant in at least two ways: 1) If the __getattr__ only calculates the value one time and then stuffs it into the instance dictionary, now you are really comparing the relative speed of properties vs. lookup of an attribute in the instance dict. If you're at all concerned about speed, I think there is a clear winner here. 2) There is a single __getattr__ function, vs. one property for every attribute that needs a property. In cases where you can somehow easily compute the attribute names as well as the attribute values, __getattr__ can be a *lot* less code than defining dozens of properties. But you're absolutely right that, in many cases, property is the best way to go for readability (especially if the property is read-only and you're using a recent enough python to use decorators). Regards, Pat -- http://mail.python.org/mailman/listinfo/python-list
