lazy_metaclass.py

class Lazy(type):
    def __init__(cls, name, bases, dict):
        super(Lazy, cls).__init__(name, bases, dict)    
        cls.instance = None

    def check_instance(cls):
        if cls.instance is None:
            if hasattr(cls, 'instantiate'):
                setattr(cls, 'instance', getattr(cls, 'instantiate')())
            else:
                raise Exception('Must implement the instantiate class method!')
    
    def __getattr__(cls, name):
        cls.check_instance()                
        return getattr(cls.instance, name)
    
    def __getitem__(cls, key):
        cls.check_instance()                
        return cls.instance.__getitem__(name)
    
    def __iter__(cls):
        cls.check_instance()                
        return cls.__iter__()
    
    def __contains__(self, item):
        cls.check_instance()                
        return cls.__contains__(item)

new_hotness.py

class db(object):
    __metaclass__ = Lazy
    
    @classmethod
    def instantiate(cls):
        return db_connection()

def func1():
    db.execute('SELECT * FROM things')

def func2():
    db.execute('SELECT * FROM other_things')