python之"TypeError: can' t 将序列乘以 'tuple' 类型的非整数是什么意思

#Finding the volume of a box 
print("Welcome to box volume calculation! Please answer the following questions.") 
x = float(raw_input("How wide is the box? ")), 
y = float(raw_input("How high is the box? ")), 
z = float(raw_input("How long is the box? ")), 
 
"The volume of the box is " + str(x*y*z) + " units cubed." 

我收到的错误消息:

Traceback (most recent call last): 
File "C:\Python25\Scripts\Randomness.py", line 22, in <module> 
"The volume of the box is " + str(x*y*z) + " units cubed." 
TypeError: can't multiply sequence by non-int of type 'tuple' 

请您参考如下方法:

去掉要求输入的行中的逗号。这些行应该是:

x = float(raw_input("How wide is the box? ")) 
y = float(raw_input("How high is the box? ")) 
z = float(raw_input("How long is the box? ")) 

解释......形式的陈述:

x = a, b, c 

创建一个包含三个元素的元组，同样地:

x = a, 

创建一个包含一个 元素的元组。所以在这里，声明如下:

x = float(raw_input(...)), 

创建一个元素的元组，该元素是您的输入!