Michael Spencer wrote: > Dylan Moreland wrote: > > I'm trying to implement a bunch of class methods in an ORM object in > > order to provide functionality similar to Rails' ActiveRecord. This > > means that if I have an SQL table mapped to the class "Person" with > > columns name, city, and email, I can have class methods such as: > > > > Person.find_by_name > > Person.find_by_city_and_name > > Person.find_by_name_and_city_and_email > > > > I have a metaclass generating basic properties such as .name and .city, > > but I don't want to generate a class method for every permutation of > > the attributes. I'd like to have something much like __getattr__ for > > instance attributes, so that if a method like > > Person.find_by_city_and_email cannot be found, I can construct a call > > to the basic find method that hides the SQL. Is there any way of doing > > this, ... > > Sure, define __getattr__ on the type of the class i.e., the metaclass, just as > you define it on a class to provide default-attribute-lookup to its instances: > > >>> class A(object): > ... class __metaclass__(type): > ... def __getattr__(cls, attr): > ... return "%s.%s" % (cls.__name__, attr) > ... > >>> A.somefunc > 'A.somefunc' > >>> A.someotherfunc > 'A.someotherfunc' > >>> > > HTH > > Michael
Thanks! I only recently realized that I would have to learn metaclasses in order to make this work, and I'm still a bit unclear on their properties. -- http://mail.python.org/mailman/listinfo/python-list
