# Model (data handling)
class UserModel:
def get_user(self, user_id):
# Code to retrieve user from the database
pass
# View (presentation)
class UserView:
def render_user(self, user):
# Code to render user data on the screen
pass
# Controller (business logic)
class UserController:
def __init__(self):
self.model = UserModel()
self.view = UserView()
def show_user(self, user_id):
user = self.model.get_user(user_id)
self.view.render_user(user)In this example, responsibilities are clearly separated: UserModel handles the data, UserView manages presentation, and UserController handles business logic and the interaction between Model and View.
Separation of Concerns is an essential principle in software development that helps improve the structure and organization of code. By clearly separating responsibilities, software becomes easier to understand, maintain, and extend, ultimately leading to higher quality and efficiency in development.
DRY stands for "Don't Repeat Yourself" and is a fundamental principle in software development. It states that every piece of knowledge within a system should have a single, unambiguous representation. The goal is to avoid redundancy to improve the maintainability and extensibility of the code.
Single Representation of Knowledge:
Avoid Redundancy:
Facilitate Changes:
Functions and Methods:
validateInput().Classes and Modules:
Configuration Data:
Better Maintainability:
Increased Consistency:
Time Efficiency:
Readability and Understandability:
Imagine a team developing an application that needs to validate user input. Instead of duplicating the validation logic in every input method, the team can write a general validation function:
def validate_input(input_data):
if not isinstance(input_data, str):
raise ValueError("Input must be a string")
if len(input_data) == 0:
raise ValueError("Input cannot be empty")
# Additional validation logic
This function can then be used wherever validation is required, instead of implementing the same checks multiple times.
The DRY principle is an essential concept in software development that helps keep the codebase clean, maintainable, and consistent. By avoiding redundancy, developers can work more efficiently and improve the quality of their software.
PostgreSQL
