Python String isalnum()

The isalnum() method returns True if all characters in the string are alphanumeric (either alphabets or numbers). If not, it returns False.

The syntax of isalnum() is:

string.isalnum()

isalnum() Parameters

The isalnum() doesn't take any parameters.


Return Value from isalnum()

The isalnum() returns:

  • True if all characters in the string are alphanumeric
  • False if at least one character is not alphanumeric

Example 1: Working of isalnum()

name = "M234onica"
print(name.isalnum())

# contains whitespace
name = "M3onica Gell22er "
print(name.isalnum())

name = "Mo3nicaGell22er"
print(name.isalnum())

name = "133"
print(name.isalnum())

When you run the program, the output will be:

True
False
True
True

Example 1: Working of isalnum()

name = "M0n1caG3ll3r"

if name.isalnum() == True:
   print("All characters of string (name) are alphanumeric.")
else:
    print("All characters are not alphanumeric.")

When you run the program, the output will be:

All characters of string (name) are alphanumeric.

Checkout these related String methods as well: