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Single Responsibility

Overview

The reason for single responsibility is having a centralized place to change code. Your class or module must not contain multiple tasks or jobs. It's a way to have clean code.

Best Practices

  • Segregate the software into concentric layers, with clear, unyielding dependency rules.
  • Identify responsibilities, ask “What is this class supposed to do?”
  • Use descriptive names for classes and methods to reflect their single purpose (e.g., EmailService instead of NotificationManager).

Single Responsibility Principle (SRP)

Real-world scenario

Got this example from Geeks for Geeks

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# Class for baking bread
class BreadBaker:
    def bakeBread(self):
        print("Baking high-quality bread...")

# Class for managing inventory
class InventoryManager:
    def manageInventory(self):
        print("Managing inventory...")

# Class for ordering supplies
class SupplyOrder:
    def orderSupplies(self):
        print("Ordering supplies...")

# Class for serving customers
class CustomerService:
    def serveCustomer(self):
        print("Serving customers...")

# Class for cleaning the bakery
class BakeryCleaner:
    def cleanBakery(self):
        print("Cleaning the bakery...")

def main():
    baker = BreadBaker()
    inventoryManager = InventoryManager()
    supplyOrder = SupplyOrder()
    customerService = CustomerService()
    cleaner = BakeryCleaner()

    # Each class focuses on its specific responsibility
    baker.bakeBread()
    inventoryManager.manageInventory()
    supplyOrder.orderSupplies()
    customerService.serveCustomer()
    cleaner.cleanBakery()

if __name__ == "__main__":
    main()

The Single Responsibility Principle (SRP): A view of SRP at different levels of architecture