Why does the server immediately stop working when starting the server?

Question

Flask

It was written in the documentation that by default it will start at 127.0.0.1:5000
But when the file is opened, it executes a function and the server stops working immediately and waits for the next command on the command line, and the file is not working.

from flask import Flask
app = Flask(__name__)

@app.route("/")
def home():
  return "hello world"

Answer 1

The code you provided doesn't run, just import the Flask class, set the app variable to an instance of the Flask class, and define a handler for the route. You should either change the documentation, or read it more carefully.

from flask import Flask
app = Flask(__name__)

@app.route("/")
def home():
  return "hello world"

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