isnumeric_Python字符串isnumeric（）

article/2025/11/10 19:16:02

isnumeric

Python String isnumeric() function returns True if all the characters in the string are numeric, otherwise False. If the string is empty, then this function returns False.

如果字符串中的所有字符均为数字，则Python String isnumeric（）函数将返回True ，否则返回False 。如果字符串为空，则此函数返回False 。

Python字符串isnumeric（） (Python String isnumeric())

Numeric characters include digit characters, and all characters that have the Unicode numeric value property. Formally, numeric characters are those with the property value Numeric_Type=Digit, Numeric_Type=Decimal or Numeric_Type=Numeric.

数字字符包括数字字符，以及所有具有Unicode数字值属性的字符。形式上，数字字符是具有属性值Numeric_Type =数字，Numeric_Type =十进制或Numeric_Type =数字的字符。

Let’s look at some examples of Python string isnumeric() function.

我们来看一些Python字符串isnumeric（）函数的示例。

s = '2019'print(s.isnumeric())

Output: True because all the characters in the string are numerical.

输出： True因为字符串中的所有字符都是数字。

s = 'Hello 2019'
print(s.isnumeric())

Output: False because some of the characters in the string are not numerical.

输出： False因为字符串中的某些字符不是数字。

s = ''
print(s.isnumeric())

Output: False because it’s an empty string.

输出： False因为它是一个空字符串。

Let’s look into some examples with special Unicode characters that are numerical.

我们来看一些带有数字的特殊Unicode字符的示例。

s = '¼'  # 00bc: ¼ (VULGAR FRACTION ONE QUARTER)
print(s)
print(s.isnumeric())s = '⒈⒗'  #2488: ⒈ (DIGIT ONE FULL STOP), 2497: ⒗ (NUMBER SIXTEEN FULL STOP)
print(s)
print(s.isnumeric())

Output:

输出：

¼
True
⒈⒗
True

打印所有Unicode数字字符 (Print all Unicode Numeric Characters)

We can use unicodedata module to print all the unicode characters that are considered as numeric.

我们可以使用unicodedata模块来打印所有被视为数字的unicode字符。

import unicodedatacount = 0
for codepoint in range(2 ** 16):ch = chr(codepoint)if ch.isnumeric():print(u'{:04x}: {} ({})'.format(codepoint, ch, unicodedata.name(ch, 'UNNAMED')))count = count + 1
print(f'Total Number of Numeric Unicode Characters = {count}')

Output:

输出：

0030: 0 (DIGIT ZERO)
0031: 1 (DIGIT ONE)
...
ff16: ６ (FULLWIDTH DIGIT SIX)
ff17: ７ (FULLWIDTH DIGIT SEVEN)
ff18: ８ (FULLWIDTH DIGIT EIGHT)
ff19: ９ (FULLWIDTH DIGIT NINE)
Total Number of Numeric Unicode Characters = 800

I never thought that there will be 800 Unicode characters that are numeric. 🙂

我从没想过会有800个数字Unicode字符。 🙂

f-strings in Python. Python中的f字符串。

GitHub Repository. GitHub存储库中签出更多Python示例。

Reference: Official Documentation

参考：官方文档