Easily learn how to install and configure Flask

Easily learn how to install and configure Flask, you need specific code examples

Introduction:
Flask is a lightweight Python for building web applications frame. It is easy to learn, has flexible design concepts and rich extension functions, so it is widely used in the field of web development. This article will introduce you to the installation and configuration methods of Flask, and provide specific code examples to help you get started easily.

1. Install Flask
To install Flask, you first need to ensure that the Python environment is installed on the computer (Python3.x version is recommended). Next, follow the steps below to install:

1. Open a terminal or command prompt and enter the following command to install Flask:

   pip install flask

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   If you are using the Python3.x version , you may need to use the pip3 command:

   pip3 install flask

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2. After the installation is completed, you can verify whether the installation is successful through the following command:

   flask --version

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2. Create Flask application
After the installation is complete, we can create a simple Flask application to verify whether it is configured correctly. Please follow these steps:

1. Create a new Python file, for example app.py, and enter the following code:

   from flask import Flask
   
   app = Flask(__name__)
   
   @app.route('/')
   def hello_world():
       return 'Hello, Flask!'
   
   if __name__ == '__main__':
       app.run()

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2. Save file and execute the following command in the terminal or command prompt to start the application:

   python app.py

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3. Open the browser and enter http://localhost:5000/, you will see "Hello, Flask" displayed on the page !", which means the app ran successfully.

3. Configure Flask application
Flask provides many configuration options that can be configured according to needs. The following are some commonly used configuration methods:

1. Use configuration file
   Create a config.py file and enter the following content:

   DEBUG = True
   SECRET_KEY = 'your_secret_key'

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   Import the configuration file in the application , and use the configuration items:

   app.config.from_pyfile('config.py')

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2. Use environment variables
   Use environment variable configuration in the application:

   import os
   
   app.config['DEBUG'] = os.environ.get('DEBUG')
   app.config['SECRET_KEY'] = os.environ.get('SECRET_KEY')

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3. Usage examples Configure the configuration class
   Create a config.py file and enter the following content:

   class Config:
       DEBUG = True
       SECRET_KEY = 'your_secret_key'
   
   app.config.from_object(Config)

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After the configuration is completed, you can use these configurations in the application. For example, you can use the following code in the view function:

from flask import current_app

@app.route('/')
def hello_world():
    debug = current_app.config.get('DEBUG')
    secret_key = current_app.config.get('SECRET_KEY')
    return f'Debug: {debug}, Secret Key: {secret_key}'

IV. Summary
Through the introduction of this article, you should already know how to install and configure the Flask framework. Flask is a very flexible and easy-to-learn framework with rich extension functions that can meet the needs of various web application development. I hope that through the guidance of this article, you can successfully start using Flask to build your own web applications. Happy studying!

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