当控制台显示“正在运行”时，浏览器上出现错误404http://127.0.0.1:5000/ "

Question

即使Flask应用程序在同一端口上的本地主机上运行，浏览器也会显示404错误。可能遗漏了什么

• 视窗10
• Python 3.7.6

我已经设置了virtualenv并运行

• 设置ExecutionPolicy不受限制-强制

我已经激活了bat文件

• env\scripts\activate.bat

(env) PS G:\Flasktut> set FLASK_APP=app.py
(env) PS G:\Flasktut> flask run
  * Environment: production
WARNING: This is a development server. Do not use it in a production deployment.
Use a production WSGI server instead.
  * Debug mode: off
  * Running on http://127.0.0.1:5000/ (Press CTRL+C to quit)
127.0.0.1 - - [17/Jul/2020 15:24:10] "GET / HTTP/1.1" 404 -
(env) PS G:\Flasktut> flask run
  * Environment: production
    WARNING: This is a development server. Do not use it in a production deployment.
    Use a production WSGI server instead.
  * Debug mode: off
  * Running on http://127.0.0.1:5000/ (Press CTRL+C to quit)
127.0.0.1 - - [17/Jul/2020 15:32:38] "GET / HTTP/1.1" 404 -

我的app.py代码

from flask import Flask

app = Flask(__name__)

app.route('/')

def index():
    return 'hello world'

if __name__ == "__main__":

    app.run(debug=True)

Answer 1

app.route('/')

def index():
    return 'hello world'

您忘记了@行之前的app.route('/')

Flask的^{}不是一个常规函数调用，而是一个装饰器。再次查看Flask文档中的Quickstart教程。它用于将URL规则/路径“附加”到特定函数，在本例中为/路径（http://127.0.0.1:5000+/）

它应该是@app.route('/')