An identifier is a sequence of characters used to provide a name for variables, functions, classes, and other program elements. elements within a program.
Rules for Identifier
- Python is case-sensitive, meaning
Lineandlineare distinct identifiers. - Identifiers can contain letters, digits, and underscores (_). However, they cannot begin with a digit.
- Underscores are often used to enhance the readability of long identifier names, but they should not be the first character.
- Spaces are not permitted within identifiers. Using spaces would split the identifier into two separate entities, causing a syntax error.
Keywords
- A keyword is an identifier that has predefined meaning in a programming language. Therefore, keywords cannot be used as “regular” identifiers. Doing so will result in a syntax error.
Use the help() function to explore Python’s keywords and understand their predefined meanings.