Python 为什么乘法会多次重复这个数字？
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Why does multiplication repeats the number several times?
提问by user1704332
I don't know how to multiply in Python.
我不知道如何在 Python 中进行乘法运算。
If I do this:
如果我这样做：
price = 1 * 9
It will appear like this:
它会是这样的：
111111111
And the answer needs to be 9(1x9=9)
答案必须是9（1x9=9）
How can I make it multiply correctly?
我怎样才能让它正确繁殖？
回答by dm03514
Use integers instead of strings.
使用整数而不是字符串。
make sure to cast your string to ints
确保将您的字符串转换为整数
price = int('1') * 9
price = int('1') * 9
The actual example code you posted will return 9not 111111111
您发布的实际例子的代码将返回9不111111111
回答by ronak
In [58]: price = 1 *9
In [59]: price
Out[59]: 9
回答by Rohit Jain
Only when you multiply integer with a string, you will get repetitive string..
只有当您将整数与字符串相乘时，您才会得到重复的字符串..
You can use int()factory method to create integer out of string form of integer..
您可以使用int()工厂方法从整数的字符串形式创建整数..
>>> int('1') * int('9')
9
>>>
>>> '1' * 9
'111111111'
>>>
>>> 1 * 9
9
>>>
>>> 1 * '9'
'9'
- If both operand is int, you will get multiplication of them as int.
- If first operand is string, and second is int.. Your string will be repeated that many times, as the value in your integer 2nd operand.
- If first operand is integer, and second is string, then you will get multiplication of both numbers in string form..
- 如果两个操作数都是 int，您将得到它们的乘积为 int。
- 如果第一个操作数是字符串，第二个是 int.. 您的字符串将重复多次，作为整数第二个操作数中的值。
- 如果第一个操作数是整数，第二个是 string，那么您将获得字符串形式的两个数字的乘法。
回答by dkamins
It's the difference between strings and integers. See:
这是字符串和整数之间的区别。看：
>>> "1" * 9
'111111111'
>>> 1 * 9
9
回答by Joseph Victor Zammit
Should work:
应该管用：
In [1]: price = 1*9
In [2]: price
Out[2]: 9
回答by larsga
I think you're confused about types here. You'll only get that result if you're multiplying a string. Start the interpreter and try this:
我认为你对这里的类型感到困惑。如果您将字符串相乘，您只会得到那个结果。启动解释器并尝试以下操作：
>>> print "1" * 9
111111111
>>> print 1 * 9
9
>>> print int("1") * 9
9
So make sure the first operand is an integer (and not a string), and it will work.
所以确保第一个操作数是一个整数（而不是字符串），它会起作用。
回答by Chimp
You cannot multiply an integer by a string. To be sure, you could try using the int (short for integer which means whole number) command, like this for example -
不能将整数乘以字符串。可以肯定的是，您可以尝试使用 int（整数的缩写，表示整数）命令，例如 -
firstNumber = int(9)
secondNumber = int(1)
answer = (firstNumber*secondNumber)
Hope that helped :)
希望有所帮助:)
