Python 3 reference · String Methods

Python String isidentifier() Method

Return True if the string is a valid Python identifier: a name you could use for a variable, function or class.

Syntax

str.isidentifier()

True or False.

Valid namesTry it yourself

for s in ["total", "_private", "2fast", "my-var", "class"]:
    print(repr(s), s.isidentifier())

Output

'total' True
'_private' True
'2fast' False
'my-var' False
'class' True

Also exclude keywordsTry it yourself

import keyword
name = "class"
print(name.isidentifier() and not keyword.iskeyword(name))

Output

False

Version	Change
Python 3.0	Added

str.isalnum() · Return True if every character is a letter or a digit and the string isn't empty.
Python Strings · tutorial