Python str.isdecimal() 和 str.isdigit() 区别示例
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str.isdecimal() and str.isdigit() difference example
提问by Phoenix
Reading python docs I have come to .isdecimal() and .isdigit() string functions and i'm not finding literature too clear on their usable distinction. Could someone supply me with code examples of where these two functions differentiate please.
阅读 python 文档我来到了 .isdecimal() 和 .isdigit() 字符串函数，我没有找到关于它们可用区别的文献太清楚。有人可以向我提供这两个函数区别的代码示例。
Similar behaviour:
类似行为：
>>> str.isdecimal('1')
True
>>> str.isdigit('1')
True
>>> str.isdecimal('1.0')
False
>>> str.isdigit('1.0')
False
>>> str.isdecimal('1/2')
False
>>> str.isdigit('1/2')
False
采纳答案by Henry Keiter
There aredifferences, but they're somewhat rare*. It mainly crops up with various unicode characters, such as 2:
有有差异，但他们有些罕见*。它主要包含各种 unicode 字符，例如2：
>>> c = '\u00B2'
>>> c.isdecimal()
False
>>> c.isdigit()
True
You can also go further down the careful-unicode-distinction rabbit hole with the isnumericmethod:
您还可以使用以下isnumeric方法进一步深入细致的 unicode-distinction 兔子洞：
>>> c = '\u00BD' # ?
>>> c.isdecimal()
False
>>> c.isdigit()
False
>>> c.isnumeric()
True
*At least, I've never encountered production code that needs to distinguish between strings that contain different types of these exceptional situations, but surely use cases exist somewhere.
*至少，我从未遇到过需要区分包含这些异常情况的不同类型的字符串的生产代码，但肯定在某处存在用例。
回答by N Randhawa
Lets see some examples:
让我们看一些例子：
str.isdecimal()(Only Decimal Numbers)
str.isdecimal()（仅十进制数）
Is 34 a decimal number? --> Yes
34是十进制数吗？--> 是的
print("34".isdecimal()) #True
Is superscript 2 a decimal number? --> No
上标2是十进制数吗？--> 没有
print("\u00B2")
print("\u00B2".isdecimal()) #False
str.isdigit()(Decimals, Subscripts, Superscripts)
str.isdigit()（小数、下标、上标）
Is 34 a digit? --> Yes
34是数字吗？--> 是的
print("34".isdigit()) #True
Is superscript 2 a digit? --> Yes
上标2是数字吗？--> 是的
print("\u00B2")
print("\u00B2".isdigit()) #True
str.isnumeric()(Decimals, Subscripts, Superscripts, Vulgar Fractions, Roman Numerals, Currency Numerators)
str.isnumeric()（小数、下标、上标、通俗分数、罗马数字、货币分子）
Is 34 a numeric number? --> Yes
34是数字吗？--> 是的
print("34".isnumeric()) #True
Is superscript 2 a numeric number? --> Yes
上标 2 是数字吗？--> 是的
print("\u00B2")
print("\u00B2".isnumeric()) #True
Is Vulgar Fraction one Quarter numeric number? -->Yes
粗俗分数是四分之一数字吗？-->是的
print("\u00BC")
print("\u00BC".isnumeric()) #True
回答by PADYMKO
If you doubt, my advice - to code, to look a results, to draw conclusions.
如果你怀疑，我的建议 - 编码，查看结果，得出结论。
A code
一个代码
In [115]: import itertools
...:
...: line = '-' * 37
...: print(line)
...: print("| № | isdigit | isdecimal | chr")
...: print(line)
...: for number in itertools.chain(range(1000), range(4969, 4978), range(8304, 11000)):
...: char = chr(number)
...: if (char.isdigit() or char.isdecimal()):
...: print('| {0:>6} | {1:^7} | {2:^9} | {3:3} '.format(
...: number,
...: '+' if char.isdigit() else '-',
...: '+' if char.isdecimal() else '-',
...: char
...: )
...: )
...:
Look a results
看结果
-------------------------------------
| № | isdigit | isdecimal | chr
-------------------------------------
| 48 | + | + | 0
| 49 | + | + | 1
| 50 | + | + | 2
| 51 | + | + | 3
| 52 | + | + | 4
| 53 | + | + | 5
| 54 | + | + | 6
| 55 | + | + | 7
| 56 | + | + | 8
| 57 | + | + | 9
| 178 | + | - | 2
| 179 | + | - | 3
| 185 | + | - | 1
| 4969 | + | - | ?
| 4970 | + | - | ?
| 4971 | + | - | ?
| 4972 | + | - | ?
| 4973 | + | - | ?
| 4974 | + | - | ?
| 4975 | + | - | ?
| 4976 | + | - | ?
| 4977 | + | - | ?
| 8304 | + | - | ?
| 8308 | + | - | ?
| 8309 | + | - | ?
| 8310 | + | - | ?
| 8311 | + | - | ?
| 8312 | + | - | ?
| 8313 | + | - | ?
| 8320 | + | - | ?
| 8321 | + | - | ?
| 8322 | + | - | ?
| 8323 | + | - | ?
| 8324 | + | - | ?
| 8325 | + | - | ?
| 8326 | + | - | ?
| 8327 | + | - | ?
| 8328 | + | - | ?
| 8329 | + | - | ?
| 9312 | + | - | ①
| 9313 | + | - | ②
| 9314 | + | - | ③
| 9315 | + | - | ④
| 9316 | + | - | ⑤
| 9317 | + | - | ⑥
| 9318 | + | - | ⑦
| 9319 | + | - | ⑧
| 9320 | + | - | ⑨
| 9332 | + | - | ⑴
| 9333 | + | - | ⑵
| 9334 | + | - | ⑶
| 9335 | + | - | ⑷
| 9336 | + | - | ⑸
| 9337 | + | - | ⑹
| 9338 | + | - | ⑺
| 9339 | + | - | ⑻
| 9340 | + | - | ⑼
| 9352 | + | - | ⒈
| 9353 | + | - | ⒉
| 9354 | + | - | ⒊
| 9355 | + | - | ⒋
| 9356 | + | - | ⒌
| 9357 | + | - | ⒍
| 9358 | + | - | ⒎
| 9359 | + | - | ⒏
| 9360 | + | - | ⒐
| 9450 | + | - | ?
| 9461 | + | - | ?
| 9462 | + | - | ?
| 9463 | + | - | ?
| 9464 | + | - | ?
| 9465 | + | - | ?
| 9466 | + | - | ?
| 9467 | + | - | ?
| 9468 | + | - | ?
| 9469 | + | - | ?
| 9471 | + | - | ?
| 10102 | + | - | ?
| 10103 | + | - | ?
| 10104 | + | - | ?
| 10105 | + | - | ?
| 10106 | + | - | ?
| 10107 | + | - | ?
| 10108 | + | - | ?
| 10109 | + | - | ?
| 10110 | + | - | ?
| 10112 | + | - | ?
| 10113 | + | - | ?
| 10114 | + | - | ?
| 10115 | + | - | ?
| 10116 | + | - | ?
| 10117 | + | - | ?
| 10118 | + | - | ?
| 10119 | + | - | ?
| 10120 | + | - | ?
| 10122 | + | - | ?
| 10123 | + | - | ?
| 10124 | + | - | ?
| 10125 | + | - | ?
| 10126 | + | - | ?
| 10127 | + | - | ?
| 10128 | + | - | ?
| 10129 | + | - | ?
| 10130 | + | - | ?
Draw a conclusions
得出结论
As you can see, main difference between the function str.isdecimal()and str.isdigit()is that: the function str.isdecimal()return True only for numbers from 0 to 9, at the same time the function str.isdigit()return True for some other unicode-supported chars.
如您所见，函数str.isdecimal()和str.isdigit() 的主要区别在于：函数str.isdecimal()仅对 0 到 9 的数字返回 True，同时函数str.isdigit ()为其他一些支持 unicode 的字符返回 True。
