Question

完成Python教程。我创建了一个简单的脚本（myFirstFunction），它不会执行预期的操作。我期望一行输出只是两个变量相乘：

apples = raw_input("How many apples do you have?")
oranges = raw_input("How many oranges do you have?")

def myFirstFunction(apples, oranges):
    total_fruit = apples * oranges
    print total_fruit

脚本确实按预期要求输入，但不打印结果？

myName-MacBook:pythonhard me$ python ex19b.py
How many apples do you have?2
How many oranges do you have?2
myNames-MacBook:pythonhard me$

为什么不打印4？

Answer 1

这里有两个问题：

您永远不会致电myFirstFunction。这可以通过将其放在脚本的末尾来完成：
```
myFirstFunction(apples, oranges)
```
raw_input始终返回一个字符串对象。因此，在将myFirstFunction内的值相乘之前，需要将输入转换为整数。您可以将它们放在int：
中
```
apples = int(raw_input("How many apples do you have?"))
oranges = int(raw_input("How many oranges do you have?"))
```

以下是您脚本的固定版本：

apples = int(raw_input("How many apples do you have?"))
oranges = int(raw_input("How many oranges do you have?"))

def myFirstFunction(apples, oranges):
    total_fruit = apples * oranges
    print total_fruit

myFirstFunction(apples, oranges)

演示：

How many apples do you have?2
How many oranges do you have?2
4

Answer 2

你需要a）调用函数＆amp; b）将输入转换为整数，因为raw_input的结果是一个字符串。

def myFirstFunction(apples, oranges):
    total_fruit = int(apples) * int(oranges)
    print total_fruit

apples = raw_input("How many apples do you have?")
oranges = raw_input("How many oranges do you have?")

myFirstFunction(apples, oranges)

Answer 3

你应该

return total_fruit

在函数中，然后调用myFirstFunction并打印结果：

def myFirstFunction(apples, oranges):
   total_fruit = apples * oranges
   return total_fruit

apples = raw_input("How many apples do you have?")
oranges = raw_input("How many oranges do you have?")

print myFirstFunction(apples, oranges)

或只是调用myFirstFunction（当没有返回时）：

myFirstFunction(apples, oranges)

我的python脚本有什么问题？不打印变量

3 个答案: