strisdecimal
str.isdecimal is a string method in Python that returns True if all characters in a string are decimal digits and there is at least one character. It checks characters against the Unicode decimal digit category, ensuring that every character is a decimal digit (Nd), and that the string is non-empty.
- The method evaluates the entire string. If any character is not a decimal digit, or if the
- Decimal digits include characters like 0–9, as well as other Unicode decimal digits such as fullwidth
- "123".isdecimal() -> True
- "１２３".isdecimal() -> True
- "123.4".isdecimal() -> False (the period is not a decimal digit)
- "Ⅻ".isdecimal() -> False (the character is a numeric but not a decimal digit)
- "".isdecimal() -> False
- "+123".isdecimal() -> False (the plus sign is not a decimal digit)
- isdecimal is the most restrictive of the common string numeric checks. It confirms only decimal digits.
- isnumeric returns True for a broader set of numeric characters, including characters like "¼" and some numerals
- isdigit also accepts additional digit-like characters beyond the strictly decimal digits, such as superscript numbers.
- str.isdecimal is useful for validating strings that should represent non-negative decimal integers, without signs or separators.
- It will not recognize numbers written with signs, decimal points, or fractional symbols.
- For parsing numeric input, isdecimal can be used as a preliminary check before converting with int()