flask console log

from flask import Flask

app = Flask(__name__)

@app.route('/')
def hello_world():
    app.logger.debug('This is a debug message')
    app.logger.info('This is an info message')
    app.logger.warning('This is a warning message')
    app.logger.error('This is an error message')
    app.logger.critical('This is a critical message')
    return 'Hello, World!'

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

Explanation:

1. Import Flask: Imports the Flask class from the Flask package.
2. Create an instance of Flask: Initializes a Flask object named app.
3. Decorate a route: Uses the @app.route('/') decorator to define a route for the root URL '/'.
4. Define a function for the route: Creates the hello_world() function that will be executed when the root URL is accessed.
5. Logging messages: Within the hello_world() function, logs different levels of messages using the app.logger object. Messages are logged with varying severity levels: debug, info, warning, error, and critical.
6. Return a response: Returns the string 'Hello, World!' as a response when the root URL is accessed.
7. Run the Flask application: Checks if the script is executed directly (if __name__ == '__main__':) and starts the Flask web server if so.

This code creates a Flask web application with a route for the root URL and demonstrates logging different types of messages using Flask's built-in logger.