Clear and easy-to-understand Flask installation tutorial to get you started quickly

Clear and easy-to-understand Flask installation tutorial to get you started quickly, specific code examples are required

Flask is a lightweight Python web development framework, it is simple Easy to learn and flexible to expand. This article will provide you with a clear and easy-to-understand Flask installation tutorial, with specific code examples to help you get started quickly.

Step One: Install Python

First, you need to install Python on your computer. You can download the latest version of Python from the official website (https://www.python.org/downloads/). The installation process is simple, just follow the prompts step by step.

Step 2: Install the virtual environment

Next, we need to create an independent Python environment for our Flask project to avoid dependency conflicts between different Python projects. Virtual environments can help us have better control over the installation and management of Python packages.

Run the following command in the terminal to create a virtual environment:

$ python3 -m venv myenv

The above command will create a virtual environment named "myenv". You can decide the name of your virtual environment yourself.

Step 3: Activate the virtual environment

After creating the virtual environment, we need to activate it. Run the following command in the terminal:

$ source myenv/bin/activate

After activating the virtual environment, you will notice that there will be a "(myenv)" logo in front of the command prompt of the terminal, which means that you have successfully activated the virtual environment. .

Step 4: Install Flask

After activating the virtual environment, we can use the pip command to install Flask. Run the following command in the terminal:

$ pip install flask

This command will automatically install the latest version of Flask.

Step 5: Write a Hello World application

Now, we will use Flask to write a simple Hello World application. In the virtual environment, create a new directory, and then create a Python script file in the directory and name it "app.py". Write the following code in the file:

from flask import Flask

app = Flask(__name__)

@app.route('/')
def hello():
    return 'Hello, World!'

if __name__ == '__main__':
    app.run()

In the above code, we imported the Flask module and created a Flask object named "app". Next, a URL route is specified through the decorator @app.route('/'), which will be mapped to the function hello() we defined. In this function, we return a simple string "Hello, World!".

Step 6: Run the application

In the terminal, enter the directory where your application is located, and execute the following command to run the application:

$ python app.py

At this point, you will see To output similar to the following:

 * Running on http://127.0.0.1:5000/ (Press CTRL+C to quit)

Now, you can visit "http://127.0.0.1:5000/" in the browser, and you will see the page with the output "Hello, World!" .

Congratulations on successfully installing and running the Flask application!

Summary:

This article introduces the installation process of Flask and provides a simple Hello World application code example. By following the steps above, you can quickly get started with Flask and start doing more complex web development. I hope this tutorial is helpful to you, and I wish you success in learning and developing Flask!

The above is the detailed content of Clear and easy-to-understand Flask installation tutorial to get you started quickly. For more information, please follow other related articles on the PHP Chinese website!