Lazy attribute for Python

Lazy.py

class lazy(object):
    def __init__(self, default=None, name=None):
        self.default = default
        self.name = name

    def __get__(self, obj, objtype):
        if obj is None:
            return self
        if callable(self.default):
            default = self.default(obj if obj is not None else objtype)
        else:
            default = self.default
        if self.name is None:
            return default
        setattr(obj, self.name, default)
        return getattr(obj, self.name)


class Lazy(object):
    def __new__(cls, *args, **kwargs):
        obj = super(Lazy, cls).__new__(cls)
        for name in dir(obj):
            attr = getattr(cls, name)
            if attr.__class__.__name__ == 'lazy':
                setattr(cls, name, lazy(attr.default, name))
        return obj