Applying SOLID, DRY, & KISS Object-Oriented Design Principles in Python

Discover key principles for crafting efficient, scalable, and maintainable Python codebases

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Writing quality code involves striking a balance between elegance, performance, and long-term sustainability. Adopting proven design principles facilitates achieving these objectives.

This article explores prominent object-oriented design principles, namely SOLID, DRY, and KISS, and demonstrates their practical application in Python.

Principle I: Single Responsibility Principle (SRP)

According to SRP, every class should have only one reason to change. Put differently, minimize class responsibilities and isolate varying aspects.

Consider refactoring a monolithic logger class, breaking down logging levels into separate entities.

Before:

class Logger:
    def debug(self, msg):
        self._log("DEBUG", msg)

    def info(self, msg):
        self._log("INFO ", msg)

    def warning(self, msg):
        self._log("WARNING", msg)

    def _log(self, level, msg):
        print(f"{level} {msg}")

After:

class LogLevel:
    DEBUG = "DEBUG"
    INFO…