In Python, the str.isdigit() method is used to check if all characters in a string are digits. This method returns True if all characters in the string are numeric characters (i.e., 0 through 9) and there is at least one character; otherwise, it returns False.

Syntax

str.isdigit()

Example Usage

1. Basic usage with digits:

text = "12345"
result = text.isdigit()
print(result)  # Output: True

2. Including non-digit characters:

text = "123abc"
result = text.isdigit()
print(result)  # Output: False

3. Checking an empty string:

text = ""
result = text.isdigit()
print(result)  # Output: False

4. With spaces and punctuation:

text = "123 456"
result = text.isdigit()
print(result)  # Output: False

5. Using special numeric characters:

The isdigit() method also returns True for characters that are considered numeric in Unicode, such as fractions and superscripts:

text = "²³"
result = text.isdigit()  # Superscripts are considered digits
print(result)  # Output: True

6. Negative numbers and decimals:

text = "-123"
result = text.isdigit()  # Negative sign is not a digit
print(result)  # Output: False

text = "123.45"
result = text.isdigit()  # Decimal point is not a digit
print(result)  # Output: False

Important Notes

• The isdigit() method considers characters that are numeric, including those in various scripts (like Arabic numerals) and even other characters defined as digits in Unicode.
• It will return False for any string containing non-numeric characters, including letters, spaces, punctuation, and symbols.

Summary

• Use str.isdigit() to determine if a string consists entirely of digit characters.
• It returns True for strings made up only of digits (0-9) and False for any strings containing non-digit characters.