Question: what are the different properties of an identifier in python?
Answer: Identifiers can be a combination of letters in lowercase (a to z) or uppercase (A to Z) or digits (0 to 9) or an underscore _ . ... 
An identifier cannot start with a digit. ... 
Keywords cannot be used as identifiers. ... 
We cannot use special symbols like !, @, #, $, % etc. ... 
An identifier can be of any length.