Question

所以我有代码（相关代码）：

print("You have chosen to bet on the even numbers")
valin = input("How much would you like to bet?: ")
print("If it lands on an even number, you win", valin*2)

我想要它做的是打印valin的值乘以2，但不知道如何做到这一点！怎么样？

Answer 1

将输入字符串转换为int的整数：

valin = int(input("How much would you like to bet?: "))

然后像以前一样继续。

Answer 2

您的问题是，input()的结果将是str，而不是int，并且乘法对字符串具有不同的含义。这是一个例子：

>>> valin = input("How much would you like to bet?: ")
How much would you like to bet?: 20
>>> type(valin)      # valin is a string!
<type 'str'>
>>> valin * 2        # multiplication will concatenate the string to itself
'2020'
>>> int(valin) * 2   # first convert it to an int, then multiply
40

你需要像larsmans建议的那样做，并在乘法之前将其转换为int。这是一个带有一些额外验证的版本：

print("You have chosen to bet on the even numbers")
while True:
    try:
        valin = int(input("How much would you like to bet?: "))
        break
    except ValueError:
        print("Invalid input, please enter an integer")
print("If it lands on an even number, you win", valin*2)

Answer 3

使用Python String Formatting：

print("If it lands on an even number, you win %d" % (int(valin) * 2))

编辑：您可能需要进行一些输入验证，以确保从input获得的是一个整数，或者可以解析为整数，否则再次询问。

编辑2：如果来自larsmans的评论正确，则需要将输入解析为int。修正如上。

Answer 4

print（“如果它落在偶数上，你就赢了％d”％valin * 2）

Python在“print（）”中乘以整数

4 个答案: