上下文管理,调用call函数 例:
def add3(x,y): time.sleep(1) return x + y class Timeit: def __init__(self,fn): self.fn = fn def __enter__(self): self.start = datetime.datetime.now() return self #1,返回值是self 说明返回了实例给f,f(3,4)需要call方法 def __exit__(self, exc_type, exc_val, exc_tb): self.delta = (datetime.datetime.now() - self.start).total_seconds() print(self.delta,'111111111111111111') def __call__(self, *args, **kwargs): return self.fn(*args, **kwargs) #2,call方法返回函数self存的函数self.fn #self = Timeit(add3) with Timeit(add3) as f: #3,f拿到函数,直接调用 f(3,4)