> a.sayHello
<bound method A.sayHello of <__main__.A object at 0x03F014B0
> delattr(a,'sayHello') #不能用于删除方法
Traceback (most recent call last):
 File "<pyshell#50>", line 1, in <module>
  delattr(a,'sayHello')
AttributeError: sayHello
>

class MyClass:
  # num是类属性
  num = 1

  def __init__(self, name):
    self.name = name


def main():
  test = MyClass("shemingli")

  # 删除类属性
  # 删除类属性要写类名，而不是实例名
  delattr(MyClass, "num")

  # 删除实例属性
  delattr(test, "name")

  """
    def delattr(o: Any, name: str)
    Inferred type: (o: Any, name: str) -> None

    Deletes the named attribute from the given object.
    delattr(x, 'y') is equivalent to ``del x.y''
  """
  # 注：如果属性不存在，就抛出异常


if __name__ == '__main__':
  main()