Python Constants: Enforcing Immutability

In Python, enforcing the immutability of a variable as a constant can be challenging. However, there are a couple of approaches that can help achieve this goal.

Using Enums as Constants

One way to define constants in Python is by using enums from the enum module. Here’s an example:

from enum import Enum

class Constants(Enum):
    WIDTH = 1024
    HEIGHT = 256

To access the value of a constant, you can use Constants.WIDTH.value. The use of enums provides a clear indication that these values should not be modified.

Using Naming Conventions

Another common practice in Python is to rely on naming conventions to indicate that a variable should be treated as a constant. By convention, variables that should not be changed are declared in uppercase:

WIDTH = 1024

However, it’s important to note that Python itself will not prevent the modification of these variables. It is merely a convention followed by most Python developers.

While these approaches are commonly used, it’s worth mentioning that they don’t provide complete enforcement of immutability. Developers should exercise caution when using constants and rely on code reviews and documentation to ensure their proper usage.