Python String isidentifier() Method

Python String isidentifier() method is used to check whether a string is a valid identifier or not. The method returns True if the string is a valid identifier, else returns False.

Python String isidentifier() method Syntax

Syntax:  string.isidentifier()

Parameters: The method does not take any parameters

Return Value:  The method can return one of the two values: 

• True: When the string is a valid identifier.
• False: When the string is not a valid identifier.

Python String isidentifier() Method Example

Output:

True

Note: A string is considered as a valid identifier if:

• It only consists of alphanumeric characters and underscore (_)
• Doesn’t start with a space or a number

Example 1: How isidentifier() works

Here, we have added some basic examples of using isidentifier() Method in Python

Output: 

False
True
False
True
False

Example 2: Using Python String isidentifier() Method in condition checking

Since, Python String isidentifier() returns boolean we can directly use isidentifier() inside if-condition to check if a String is an indicator or not.

Output:

geeks101 is an identifier.
GeeksForGeeks is an identifier.
admin#1234 is not an identifier.
user@12345 is not an identifier.