Introduction to flask application

Flask is a lightweight Python web framework designed to be simple and easy to use. It is often referred to as a “microframework” because it doesn’t include a lot of built-in tools or libraries. Instead, Flask provides the core functionality needed to build web applications and lets you choose the extensions and libraries you want to add for features like database interaction, user authentication, or form validation.

This design philosophy makes Flask highly flexible and ideal for building small to medium-sized applications, prototypes, and microservices.

Installation on All Operating Systems

The process for installing Flask is very similar across all major operating systems (Windows, macOS, and Linux) because it primarily relies on Python’s package manager, pip, and a virtual environment. Using a virtual environment is a best practice that isolates your project’s dependencies from your system-wide Python installation, preventing conflicts between different projects.

Here’s the step-by-step process:

1. Install Python

• Before you can install Flask, you need to have Python installed on your system. You can download the latest version from the official Python website. Most Linux distributions and macOS come with Python pre-installed, but it’s a good idea to ensure you have a recent version (3.x) and that pip is available.

2. Create a Project Directory

• First, create a new folder for your project and navigate into it using your terminal or command prompt.

mkdir my-flask-app

cd my-flask-app

3. Create a Virtual Environment

This is the most important step for a clean and manageable project. You can use Python’s built-in venv module.

Windows:python -m venv venv

macOS / Linux:python3 -m venv venv

4. Activate the Virtual Environment

• Once created, you must activate the virtual environment. Your command prompt or terminal will usually show the name of the activated environment to indicate that you’re working within it.

Windows:venv\Scripts\activate

macOS / Linux:source venv/bin/activate

5. Install Flask

• With the virtual environment active, use pip to install Flask. This command downloads and installs Flask and its required dependencies (Werkzeug, Jinja, etc.) into your isolated environment. pip install Flask

6. Verify the Installation

To confirm that Flask is installed, you can try importing it in a Python interpreter or by running a command.pip show Flask

This command will display information about the installed Flask package, confirming that the installation was successful. You are now ready to start building your Flask application. For a visual guide on the installation process, you can watch this Flask installation on Windows 11 guide. This video provides a step-by-step tutorial on setting up and running a Flask application on a Windows 11 system.