Question

我在绝对初学者（第三版）中使用Python编程，不幸的是在游戏早期就遇到了问题。

有人能指出我以下代码有什么问题吗？

price = float(input("Uh oh, looks like dinner is over. Time to calculate the tip! How much was the bill?"))

price_15 = price * .15

price_20 = price * .20

print("If you're feeling cheap you can give a 15% tip, which would be " + price_15 + "dollars. However, if you want do be a decent human being, you will give a 20% tip, which will set you back " + price_20 + "dollars")

错误：

"/Users/Gabe/Desktop/Python/Challene 2.3.py", line 5, in <module> + price_20 + "dollars") TypeError: Can't convert 'float' object to str implicitly

Answer 1

由于您将float连接到字符串而未将其转换为字符串，因此您收到错误。您应该将float转换为字符串，或者只使用逗号分隔您的参数以进行打印。

print("If you're feeling cheap you can give a 15% tip, which would be " + str(price_15) + "dollars. However, if you want do be a decent human being, you will give a 20% tip, which will set you back " + str(price_20) + "dollars")

print("If you're feeling cheap you can give a 15% tip, which would be " , price_15 , "dollars. However, if you want do be a decent human being, you will give a 20% tip, which will set you back " , price_20 , "dollars")

Answer 2

如果你认为它更具可读性，请考虑这种替代格式：

print("If you're feeling cheap you can give a 15%% tip, which would be %d dollars. However, if you want do be a decent human being, you will give a 20%% tip, which will set you back %d dollars" % (price_15, price_20))

双倍百分比是为了逃避百分比字符＆＃34; %%＆＃34;，＆＃34;％d＆＃34;将您的变量转换为字符串中的十进制，但作为替代方案，您可以使用＆＃34;％f＆＃34;保持它作为一个浮动（并没有四舍五入到最接近的美元）。

参考：https://docs.python.org/2/library/stdtypes.html#string-formatting-operations

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2 个答案: