On Fri, Oct 5, 2012 at 11:39 AM, Ethan Furman <et...@stoneleaf.us> wrote: > There is a StackOverflow question [1] that points to this on-line book [2] > which has a five-step sequence for looking up attributes: > >> When retrieving an attribute from an object (print >> objectname.attrname) Python follows these steps: >> >> 1. If attrname is a special (i.e. Python-provided) attribute for >> objectname, return it. >> >> 2. Check objectname.__class__.__dict__ for attrname. If it exists and >> is a data-descriptor, return the descriptor result. Search all bases >> of objectname.__class__ for the same case. >> >> 3. Check objectname.__dict__ for attrname, and return if found. If >> objectname is a class, search its bases too. If it is a class and a >> descriptor exists in it or its bases, return the descriptor result. >> >> 4. Check objectname.__class__.__dict__ for attrname. If it exists and >> is a non-data descriptor, return the descriptor result. If it exists, >> and is not a descriptor, just return it. If it exists and is a data >> descriptor, we shouldn't be here because we would have returned at >> point 2. Search all bases of objectname.__class__ for same case. >> >> 5. Raise AttributeError > > I'm thinking step 1 is flat-out wrong and doesn't exist. Does anybody know > otherwise?
I think step 1 refers to looking up attributes like "foo.__class__" or "foo.__dict__" themselves. -- http://mail.python.org/mailman/listinfo/python-list
