Python 为什么 isnumeric 不起作用？
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Why isn't isnumeric working?
提问by Anton
I was going through a very simple python3 guide to using string operations and then I ran into this weird error:
我正在阅读一个非常简单的 python3 使用字符串操作的指南，然后我遇到了这个奇怪的错误：
In [4]: # create string
string = 'Let\'s test this.'
# test to see if it is numeric
string_isnumeric = string.isnumeric()
Out [4]: AttributeError Traceback (most recent call last)
<ipython-input-4-859c9cefa0f0> in <module>()
3
4 # test to see if it is numeric
----> 5 string_isnumeric = string.isnumeric()
AttributeError: 'str' object has no attribute 'isnumeric'
The problem is that, as far as I can tell, strDOEShave an attribute, isnumeric.
问题是，据我所知，str确实有一个属性，isnumeric.
回答by theage
isnumeric()only works on Unicode strings. To define a string as Unicode you could change your string definitions like so:
isnumeric()仅适用于 Unicode 字符串。要将字符串定义为 Unicode，您可以像这样更改字符串定义：
In [4]:
s = u'This is my string'
isnum = s.isnumeric()
This will now store False.
这现在将存储 False。
Note: I also changed your variable name in case you imported the module string.
注意：如果您导入了模块字符串，我还更改了您的变量名称。
回答by Alexander Ejbekov
No, strobjects do not have an isnumericmethod. isnumericis only available for unicode objects. In other words:
不，str对象没有isnumeric方法。isnumeric仅适用于 unicode 对象。换句话说：
>>> d = unicode('some string', 'utf-8')
>>> d.isnumeric()
False
>>> d = unicode('42', 'utf-8')
>>> d.isnumeric()
True
回答by nvd
One Liners:
一个班轮：
unicode('200', 'utf-8').isnumeric() # True
unicode('unicorn121', 'utf-8').isnumeric() # False
Or
或者
unicode('200').isnumeric() # True
unicode('unicorn121').isnumeric() # False
回答by Swarit Agarwal
if using python 3 wrap string around stras shown below
如果使用 python 3 环绕str 的字符串，如下所示
str('hello').isnumeric()
str('你好').isnumeric()
This way it behaving as expected
这样它的行为符合预期
