Python：函数定义在所需输出的中间不断返回'None'

Question

好吧，所以我正在为我们的女朋友制作我们的6周年代码。 我是一个完整的编程noob。我正在编写一些非常简单的代码，基本上是一个输入数字输入机器，以便用户（她）接收字符串输出。

我一直看到“无”，当我运行我的代码。为什么？ 在这里。

def love(n): 
    if n < 0 : 
    print "Why would it be negative?!" 
    if n == 0 : 
     print "well that is just hurtful" 
    if n == 1 : 
    print "I REALLY love you" 
    if n == 2 : 
    print "You make me smile at least once, each and every day" 
    if n == 3 : 
    print"you wouldn't believe how annoying it was to get this program to run properly! but it was worth it" 
    if n == 4 : 
     print "let's " + "shoot a little higher than that" 
    else: 
    print "I honestly can't see myself without you anymore" 


print love(0) 

print "Wanna try again? :D " 

Answer 1

你的函数具有None默认的返回值，所以当你print出来，将打印None。

只需调用没有print语句的函数即可。

或者，您可以将函数中的所有print语句替换为return，并将其变为if-elif-else块，因为它们都是互斥的操作。然后，打印love(0)实际上会打印出返回值。

Answer 2

love(0) # is all you need. 

---

你不需要调用print love()，因为你已经拥有内love打印报表。 你正在看到None为love正在做所有的工作，它没有返回任何东西。

---

另外，你需要为你只想要一个，出所有的打印操作的，在同一时间运行，以使用if-elif-else块的功能。

if n < 0 : 
    print "Why would it be negative?!" 
elif n == 0 : 
     print "well that is just hurtful" 
elif n == 1 : 
    print "I REALLY love you" 
elif n == 2 : 
    print "You make me smile at least once, each and every day" 
elif n == 3 : 
    print"you wouldn't believe how annoying it was to get this program to run properly! but it was worth it" 
elif n == 4 : 
     print "let's " + "shoot a little higher than that" 
else: 
    print "I honestly can't see myself without you anymore" 

虽然，超越2，打印一切不会伤害;）

_{我100 ^日答案就这样！好极了 ！}