Flask is a micro web framework for Python that allows the Model-View-Controller (MVC) architectural pattern. The MVC pattern is a design pattern commonly used in web development to separate the application’s concerns into three interconnected components:
Model
Models represent the data and the business logic of the application. They deal with the storage, retrieval, and manipulation of data. It includes the database models, data structures, and methods for data manipulation. Unlike Django, flask doesn’t have a built-in object-relational mapper (ORM). You have the flexibility to choose your preferred ORM.
View
Handles the presentation layer of the application. It defines how the data should be displayed to the user and interacts with the user interface. In Flask, the views are implemented using routes and view functions. Routes define the URLs that the application responds to, and the associated view functions handle the logic for generating the response. These view functions retrieve data from the model, process it, and render templates or return JSON responses. Templates are usually written using Jinja2, a powerful templating engine that allows embedding dynamic data in HTML.
Controller:
Manages the flow of data between the model and the view. It receives user input, performs appropriate actions, and updates the model or view accordingly. Controllers in Flask are typically implemented within the view functions or as separate modules. The controller receives user input from the request, interacts with the model to retrieve or update data, and then determines the appropriate response. It manages the flow of data between the model and the view, ensuring that the necessary data is retrieved, processed, and passed to the view for rendering.
That said, Flask is flexible and doesn’t enforce strict adherence to the MVC pattern.
Developers have the freedom to structure their Flask applications in various ways based on their specific requirements.
Flask’s flexibility allows you to structure your application in various ways, depending on its scope, complexity and your preferences. Some Flask applications may have a dedicated folder for models, views, and controllers, while others may integrate them within a single file or follow a modular approach. You have the freedom to organize your application based on your specific needs.
It’s worth noting that while Flask follows the MVC architectural pattern, it’s often referred to as a micro framework because it provides a minimalistic set of tools and leaves many design decisions to the developer. This allows for greater flexibility and adaptability but also requires more responsibility in organizing and structuring your code.