Question

我正在尝试用Python制作一个英寸到厘米（反之亦然）转换器。

print "CM TO INCH (VV) CONVERSION. ENTER SPECIFIED NUMBER:"
inches = 2.54 #centimetres
cms = 0.393701 #inches
number = raw_input()
answercms = number * inches
answerinches = number * cms
print "%d centimetres are %d inches. %d inches are %d centimetres." % (number, answerCms, number, answerinches)

在Powershell中运行脚本后，会出现此错误：

Traceback (most recent call last):
   File "inchcm.py", line 5, in <module>
     answercms = number * inches
TypeError: can't multiply sequence by non-int of type 'float'

我知道这个问题已经出现过一两次，但我不明白答案。

Answer 1

raw_input()返回一个字符串。您不能将字符串与数字相乘，因此您需要首先将数字字符串转换为实际数字格式，例如使用float()函数：

number = raw_input()
answercms = float(number) * inches

您可以使用type()来检查变量的实际类型：

>>> type(number)
<type 'str'>
>>> type(float(number))
<type 'float'>

不能将序列乘以'float'类型的非int

1 个答案: