Somewhat silly example:
I know you've hedged this by calling it a "silly" example, but I would like to point out that your set_X methods are unnecessary -- since Python allows you to overload attribute access, getters and setters are generally unnecessary.
class Address: def __init__(): self.displayed_name = '' self.adr = '' self.city = '' self.state = '' def set_name(name): self.displayed_name = name def set_adr(adr): self.adr = adr def set_city(city): self.city = city def set_state(state): self.state = state
class Phone: def __init__(): self.displayed_name = '' self.number = '' def set_name(name): self.displayed_name = name def set_number(number): self.number = number
class Customer: def __init__(): self.last_name = '' self.first_name = '' self.adr = Adr() self.phone = Phone() def set_adr_name(name): self.adr.set_name(name) def set_adr_adr(adr): self.adr.set_adr(adr) def set_adr_city(city): self.adr.set_city(city) def set_adr_state(state): self.adr.set_state(state) def set_phone_name(name): self.phone.set_name(name) def set_phone_number(number): self.phone.set_number(number)
IOW, all the adr methods go to the corresponding method in self.adr, all the phone methods go to self.phone, theorectically etc for other rich attributes.
What I'd really like is to say, "the following list of methods pass all their arguments through to a method of the same name in self.adr, and the following methods do the same but to self.phone." Is there some sane way to express that in python?
py> class Address(object): ... def __init__(self, city, state): ... self.city = city ... self.state = state ... py> class Customer(object): ... def __init__(self, name, addr): ... self.name = name ... self.addr = addr ... def __getattr__(self, attr): ... if attr.startswith('adr_'): ... return getattr(self.addr, attr[4:]) ... raise AttributeError(attr) ... py> c = Customer("Steve", Address("Tucson", "AZ")) py> c.adr_city 'Tucson' py> c.adr_state 'AZ'
I've used a slightly different example from yours, but hopefully you can see how to apply it in your case. The __getattr__ method is called when an attribute of an object cannot be found in the normal locations (e.g. self.__dict__). For all attributes that begin with "adr_", I delegate the attribute lookup to the self.addr object instead.
Steve -- http://mail.python.org/mailman/listinfo/python-list
