How do you define a constant variable in Python?

In Python, constants are not enforced by the language itself but are typically defined by convention. The most common practice is to use uppercase letters for the variable name to indicate that it is intended to be a constant. This convention is widely adopted in the Python community and helps developers understand which variables are meant to remain unchanged throughout the program.

For example, a variable named MAX_VALUE clearly communicates that it is a constant representing a maximum value, which should not be altered during execution. While this does not prevent accidental changes to the value, it serves as a guideline for developers to treat the variable as immutable.

Other choices, such as using a special keyword, brackets, or making it private, do not align with Python's approach to defining constants. Python does not have a built-in keyword for constants, nor does it require specific syntax like brackets for variable definitions. The idea of making a variable private does not inherently denote a constant; rather, it generally relates to the visibility and accessibility of the variable within certain scopes or classes.