Flask 极简入门

创建虚拟环境

mkdir flask-demo

cd flask-demo

# 默认会创建.venv目录
uv venv        

# 激活

source .venv/bin/activate

# 如果想要取消激活的话可以使用如下命令

deactivate

配置VS Code

设置VS Code使用的Python虚拟环境，编辑.vscode/settings.json,添加如下内容

{
  "python.defaultInterpreterPath": "${workspaceFolder}/.venv/bin/python"
}

初始化项目

# 在我们创建的项目目录flask-demo下执行
uv init

uv配置国内源

编辑pyproject.toml添加如下内容

[[tool.uv.index]]
name = "tsinghua"
url = "https://pypi.tuna.tsinghua.edu.cn/simple"
default = true

安装Flask

uv add flask

Flask示例程序

from flask import Flask


# 创建一个Flask对象
app = Flask(__name__)

@app.route('/')
def hello_world():
    return "hello world!"

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

运行

默认监听在5000端口

(flask-demo) ➜  flask-demo git:(master) ✗ uv run main.py                                                  
 * Serving Flask app 'main'
 * Debug mode: off
WARNING: This is a development server. Do not use it in a production deployment. Use a production WSGI server instead.
 * Running on http://127.0.0.1:5000
Press CTRL+C to quit
127.0.0.1 - - [23/Apr/2026 23:00:53] "GET / HTTP/1.1" 200 -

测试

➜  ~ curl http://127.0.0.1:5000  
hello world!%