Python String isalnum() Function

The String isalnum() method returns True if the string is not empty and all the characters are alphanumeric. Otherwise, it returns False.

note

A character is alphanumeric if it is either a letter [a-z],[A-Z] or a number [0-9].

Syntax

my_string.isalnum()

isalnum() Parameters

Python String isalnum() function does not take any parameters.

isalnum() Return Value

Python String isalnum() function returns:

• True if ALL characters in the string are alphanumeric.
• False if AT LEAST ONE character is NOT alphanumeric.

Examples

Example 1: Check if a String is alphanumeric with isalnum()

The isalnum() method returns True if all characters are alphanumeric.

For example, let's check if all characters in the string abc123 are alphanumeric:

my_str = 'abc123'
result = my_str.isalnum()
print(result) # Output: True

output

True

Example 2: Check if a String with Special Characters is alphanumeric with isalnum()

The isalnum() method returns False if at least one character is not alphanumeric.

my_str = 'abc@123'
result = my_str.isalnum()
print(result) # Output: False

output

False

Example 3: Check if an empty String is alphanumeric with isalnum()

The isalnum() method returns False if the string is empty.

my_str = ''
result = my_str.isalnum()
print(result) # Output: False

output

False