为什么在Python中打印函数的返回值？

Question

很新的蟒蛇，尝试这一点 -

def newlines(): 
    print() 
    print() 
    print()  
question = "Which online Course you have signed up, dude?" 
response = "Good Luck to you, dude!" 
print(question), newlines(), input(), newlines(), print(response) 

在Python 3.2 *输出是这

Which online Course you have signed up, dude? 



Nothing 



Good Luck to you, dude! 

(None, None, "Nothing", None) # Where this output is coming from ? 

而且这是不是与蟒蛇3.3测试版

Answer 1

您必须在交互式shell中。当我运行你的代码作为一个文件，我得到这样的输出：

$ python3.2 test.py 
Which online Course you have signed up, dude? 



dlkjdf 



Good Luck to you, dude! 
$ 

你只有你在控制台输出：

>>> def newlines(): 
...  print() 
...  print() 
...  print()  
... 
>>> question = "Which online Course you have signed up, dude?" 
>>> response = "Good Luck to you, dude!" 
>>> 
>>> print(question), newlines(), input(), newlines(), print(response) 
Which online Course you have signed up, dude? 



dljdldk 



Good Luck to you, dude! 
(None, None, 'dljdldk', None, None) 
>>> 

这是因为控制台将打印的最后一件事表示你输入了。最后一个语句实际上是一个元组，所以它在最后打印出来。这里有一些例子：

>>> 3 
3 
>>> 4 
4 
>>> 3, 4, None, "hey" 
(3, 4, None, 'hey') 

Answer 2

发生的事情当你写这个。 ：

print(question), newlines(), input(), newlines(), print(response)

它实际上是一个元组，它包含每个函数的结果。

只需打破个别电话上的呼叫即可解决您的问题。

print(question) 
newlines() 
input() 
newlines() 
print(response)