Tip

The irrelevance of immutability

Immutability can become an attractive nuisance. It's sometimes justified by the mythical "malicious programmer" who modifies the constant value in their application. As a design consideration, this is silly. This mythical, malicious programmer can't be stopped this way. There's no easy way to "idiot-proof" code in Python. The malicious programmer has access to the source and can tweak it just as easily as they can write code to modify a constant.

It's better not to struggle too long to define the classes of immutable objects. In Chapter 3, Attribute Access, Properties, and Descriptors, we'll show ways to implement immutability that provides suitable diagnostic information for a buggy program.