python之我在类型转换时犯了什么错误

我在试图计算 calc 值的行中遇到错误

num1 = input("Enter first number:") 
num2 = input("Enter second number:") 
num3 = input("Enter third number:") 
 
print("Output:") 
calc = float((num1 + num2 + num3)/ 2) 
print("{0}+{1}+{2})/2 is:{3}".format(num1,num2,num3,calc)) 

这就是我的目的，感谢您的帮助...

num1 = float(input("Enter first number:")) 
num2 = float(input("Enter second number:")) 
num3 = float(input("Enter third number:")) 
 
print("Output:") 
calc = ((num1 + num2 + num3)/ 2) 
print("{0}+{1}+{2})/2 is:{3}".format(num1,num2,num3,calc)) 

请您参考如下方法:

输入返回字符串!所以，用int转换这三个数吧!正如评论所说，更好地直接转换为 float 。

num1 = float(input("Enter first number:")) 
num2 = float(input("Enter second number:")) 
num3 = float(input("Enter third number:")) 
 
print("Output:") 
calc = (num1 + num2 + num3)/ 2 
print("{0}+{1}+{2})/2 is:{3}".format(num1,num2,num3,calc)) 
 
>>>  
Result: 
Enter first number:12 
Enter second number:2 
Enter third number:5 
Output: 
12+2+5)/2 is:9.5 
>>>