Setting Up a Virtual Environment in Flask

Flask is a popular micro web framework for Python. To manage dependencies and avoid conflicts, it is a good practice to set up a virtual environment for your Flask projects. This article explains the steps to create and use a virtual environment with a real example.

Step 1: Install Python

Ensure you have Python installed on your system. You can download it from the official Python website (https://www.python.org/). For this example, we'll assume Python 3.x is installed.

Step 2: Install Virtualenv

Virtualenv is a tool to create isolated Python environments. To install it, open your terminal and run:

            pip install virtualenv

To verify the installation, you can run:

            virtualenv --version

Step 3: Create a Project Directory

Create a folder for your Flask project. For example:

            mkdir flask_project
            cd flask_project

Step 4: Set Up the Virtual Environment

Inside your project directory, create a virtual environment by running:

            virtualenv venv

This will create a folder named venv containing the isolated environment.

Step 5: Activate the Virtual Environment

Activate the virtual environment using the following command:

On Windows:

            venv\Scripts\activate

On macOS/Linux:

            source venv/bin/activate

After activation, your terminal prompt should show the name of the virtual environment, like (venv).

Step 6: Install Flask

With the virtual environment activated, install Flask using pip:

            pip install flask

You can verify the installation by checking the Flask version:

            flask --version

Step 7: Create a Simple Flask Application

Create a file named app.py in your project directory with the following content:

            from flask import Flask
            app = Flask(__name__)

            @app.route("/")
            def home():
                return "Hello, Flask!"

            if __name__ == "__main__":
                app.run(debug=True)

Step 8: Run the Flask Application

With the virtual environment still activated, run the application:

            python app.py

Your Flask application should start, and you can access it in your browser at http://127.0.0.1:5000/.

Step 9: Deactivate the Virtual Environment

When you are done working, deactivate the virtual environment by running:

            deactivate

Conclusion

By following these steps, you have successfully set up a virtual environment for a Flask project. This approach ensures that your project's dependencies are isolated and do not interfere with other projects.




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