decorations.py 文件源码

def singleton_contextmanager_method(func):
    cached_attr_name = '__singleton_contextmanager_method__' + func.__name__

    # Wrap with a context manager to get proper IPython documentation
    @contextmanager
    @wraps(func)
    def inner(self):
        with _singleton_contextmanager_method_attr_lock:
            try:
                cm = getattr(self, cached_attr_name)
            except AttributeError:
                cm = singleton_contextmanager(partial(func, self))
                setattr(self, cached_attr_name, cm)
        with cm as val:
            yield val

    return inner