PYTHON IDENTIFIERS
An identifier is the name of a variable, function, class, module, or other Python object, and a valid identifier conforms to the following rules:
- starts with a letter A to Z or a to z or an underscore (_)
- zero or more letters, underscores, and digits (0 to 9)
NOTE Python identifiers cannot contain characters such as @, $, and %.
Python is a case-sensitive language, so Abc and abc are different identifiers in Python. In addition, Python has the following naming conventions:
- Class names start with an uppercase letter and all other identifiers with a lowercase letter
- An initial underscore is used for private identifiers.
- Two initial underscores are used for strongly private identifiers.
A Python identifier with two initial underscores and two trailing underscore characters indicates a language-defined special name.
