observer.py 文件源码

def observable__getattribute__(f):
    """ decoratore per Observable.__getattribute__"""

    # https://bugs.python.org/issue3445
    # from functools import wraps
    # @wraps(f)
    def wrapper(*args, **kwargs):
        instance, attribute = args[:2]        
        result = f(*args, **kwargs)

        if attribute == '_Observable__observers' and result is None:
            result = weakref.WeakValueDictionary()
            setattr(instance, '_Observable__observers', result)
        return result

    return wrapper