Destructor

1

class Person(object):
    def __init__(self, name):
        self.name = name
    
    def say_something(self):
        print('I am {}. Hello'.format(self.name))
        self.run(3)
    
    def run(self, num):
        print('run '*num)

    def __del__(self):
        print('Good-Bye')

person = Person('Tom')
person.say_something()

Execution result of 1

I am Tom. Hello.
run run run 
Good-Bye

2

class Person(object):
    def __init__(self, name):
        self.name = name
    
    def say_something(self):
        print('I am {}. Hello.'.format(self.name))
        self.run(3)
    
    def run(self, num):
        print('run ' * num)
    
    def __del__(self):
        print('Good-Bye')
    
person = Person('Tom')
person.say_something()
print('#######################')

Execution result of 2

I am Tom. Hello.
run run run 
#######################
Good-Bye

After print ('#######################') No code, If the person object is no longer used The destructor del function is called.

Not like 2 ####################### On top of the If you want to output Good-Bye, You can delete the person object with del person.

3

class Person(object):
    def __init__(self, name):
        self.name = name
    
    def say_something(self):
        print('I am {}. Hello.'.format(self.name))
        self.run(3)
    
    def run(self, num):
        print('run ' * num)
    
    def __del__(self):
        print('Good-Bye')
    
person = Person('Tom')
person.say_something()
del person
print('#######################')

Execution result of 3

I am Tom. Hello.
run run run 
Good-Bye
#######################