Isnumeric vs isdigit vs isdecimal Python

The difference between Isnumeric vs isdigit vs isdecimal in Python is some may not work as you’d expect.

• isdigit method returns True is all the characters in a string are digits, and False if not.
• isnumeric method has a number of key differences from the Python isdigit method. While the isidigit method checks whether the string contains only digits, the isnumeric method checks whether all the characters are numeric.
• isdecimal method is a bit different, in that it evaluates whether a character is a decimal character, rather than a numeric character. Because of this, it will only return True if all the characters can evaluate to a base ten number, meaning that fractions and superscripts will return False.

s.isdigit()
s.isnumeric()
s.isdecimal()

By definition, isdecimal() ⊆ isdigit() ⊆ isnumeric(). That is, if a string is decimal, then it’ll also be digit and numeric.

Therefore, given a string s and test it with those three methods, there’ll only be 4 types of results.

+-------------+-----------+-------------+----------------------------------+
| isdecimal() | isdigit() | isnumeric() |          Example                 |
+-------------+-----------+-------------+----------------------------------+
|    True     |    True   |    True     | "038", "੦੩੮", "０３８"           |
|  False      |    True   |    True     | "⁰³⁸", "🄀⒊⒏", "⓪③⑧"          |
|  False      |  False    |    True     | "↉⅛⅘", "ⅠⅢⅧ", "⑩⑬㊿", "壹貳參"  |
|  False      |  False    |  False      | "abc", "38.0", "-38"             |
+-------------+-----------+-------------+----------------------------------+

Isnumeric vs isdigit vs isdecimal Python example

Simple example code difference between isdigit(), isnumeric(), and isdecimal().

def spam(s):
    for attr in 'isnumeric', 'isdecimal', 'isdigit':
        print(attr, getattr(s, attr)())


spam('½')
spam('³')
spam('Hello')
spam('123')
spam('1A')

Output:

Do comment if you have any doubts or suggestions on this Python methods comparison topic.

Note: IDE: PyCharm 2021.3.3 (Community Edition)

Windows 10

Python 3.10.1

All Python Examples are in Python 3, so Maybe its different from python 2 or upgraded versions.