gistfile1.py

class Account(object):
    address1 = '1 Potato Street'
    billing_address1 = None
    name = 'John Doe'
    billing_name = 'Jane Doe'
    
    @property
    def billing(self):
        account = self
        class c:
            def __getattr__(self, name):
                return getattr(account, 'billing_' + name) \
                       or getattr(account, name)
        return c()

account = Account()

print account.address1
# 1 Potato Street

print account.billing.address1
# 1 Potato Street

print account.name
# John Doe

print account.billing.name
# Jane Doe