Python 2-除数10每次都会返回0

Question

程序将两个用户输入的数字相除，然后乘以该数字，则程序每次都会返回0

correct = input("User, Input the amount of correct answers. :")
points_possible = input("User, Input the amount of points possible. :")

score = correct / points_possible
grade = score * 10

print grade

预期输出

if (1/2) * 10 = 5, but will output 0

Answer 1

如果您使用的是Python 2.7版本，那么从控制台获取的输入将始终为字符串形式。因此，您需要将其转换为整数。

#code in Python 3.5
correct = int(input("User, Input the amount of correct answers. :"))
points_possible = int(input("User, Input the amount of points possible. :"))

score = correct / points_possible
grade = score * 10

print(grade)

在Python 2中只得到0的原因是，如果给出整数，则只会得到整数除法。如果要进行浮点除法，则需要确保某处有小数点，以便Python知道不必将值截断为int。

#code in Python 2.7
correct = float(raw_input("User, Input the amount of correct answers. :"))
points_possible = float(raw_input("User, Input the amount of points possible. :"))

score = correct / points_possible
grade = score * 10.0

print grade

Answer 2

这是因为python需要您了解它已被浮点数除法：您可以在分隔符的末尾添加.0或键入10 / float（2）