Working With Constants in Python

This is a preview of the video course, "Defining Python Constants for Code Maintainability." In programming, the term constant refers to names representing values that don’t change during a program’s execution. Constants are a fundamental concept in programming, and Python developers use them in many cases. However, Python doesn’t have a dedicated syntax for defining constants. In practice, Python constants are just variables that never change.

This is a portion of the complete course, which you can find here:

The rest of the course covers:
- Properly define constants in Python
- Identify some built-in constants
- Use constants to improve your code’s readability, reusability, and maintainability
- Apply different approaches to organize and manage constants in a project
- Use several techniques to make constants strictly constant in Python

[NicolasChanCSY]

We can also make use of the `typing.Final` type annotation to indicate a variable is not supposed to be change.

Type checkers will raise an error message if the variable is reassigned, redefined, or overridden. While this cannot stop any change in run-time, it certainly helps identify such unintended behaviour early in compile-time.

[ag]

I didn't know you could make a 15 min video about constants.

[alcarsharif]

Constants are a lie in Python. Every variable is reassignable.