Python 3 reference · String Methods

Python String isdigit() Method

Return True if every character is a digit, including superscripts like ². Signs, spaces and decimal points return False.

Syntax

str.isdigit()

True or False.

What counts as a digitTry it yourself

print("2026".isdigit(), "3.14".isdigit(), "-1".isdigit(), "²".isdigit())

Output

True False False True

Validate a PINTry it yourself

pin = "0042"
print(len(pin) == 4 and pin.isdigit())

Output

True

Version	Change
Python 3.0	Added

str.isdecimal() · Return True if every character is a decimal digit (0–9 and their equivalents in other scripts). The strictest digit check.
str.isnumeric() · Return True if every character is numeric, including digits, fractions like ½ and numerals from other scripts.
str.isalnum() · Return True if every character is a letter or a digit and the string isn't empty.
Python Strings · tutorial