参考文章:https://www.jianshu.com/p/18a6c0c76438
1、不是必须要return
方法中没有return
ages={ "Peter": 10, "Isabel": 11, "Anna": 10, } def func(): for key in ages: if ages[key] == 10: ages[key]=1111 func()
执行结果:
2、想print方法时必须要return,将想输出的东西抛出,不然输出结果为None
ages={ "Peter": 10, "Isabel": 11, "Anna": 10, } def func(): for key in ages: if ages[key] == 10: ages[key]=1111 print(func())
执行结果:
3、加上了return,再打印方法,
ages={ "Peter": 10, "Isabel": 11, "Anna": 10, } def func(): for key in ages: if ages[key] == 10: ages[key]=1111 return ages[key] print(func())
执行结果: