背景：使用python3.6老版本，按照如下依赖，flask无法运行

如下为requirements.txt

click==8.0.4
colorama==0.4.5
dataclasses==0.8
Flask==2.0.3
importlib-metadata==4.8.3
itsdangerous==2.0.1
Jinja2==3.0.0
MarkupSafe==2.0.1
typing_extensions==4.1.1
vsearch @ file:///D:/Python_Project/Head_first/mymodules/dist/vsearch-1.0.tar.gz
Werkzeug==2.0.3
zipp==3.6.0

运行报错如下：

 

D:\Python_Project\Head_first\venv\Scripts\python.exe D:\Python_Project\Head_first\C5--构建一个Web应用\webapp\vsearch4web.py 
Traceback (most recent call last):
  File "D:\Python_Project\Head_first\C5--构建一个Web应用\webapp\vsearch4web.py", line 1, in <module>
    from flask import Flask,render_template
  File "D:\Python_Project\Head_first\venv\lib\site-packages\flask\__init__.py", line 6, in <module>
    from . import json as json
  File "D:\Python_Project\Head_first\venv\lib\site-packages\flask\json\__init__.py", line 9, in <module>
    from jinja2.utils import htmlsafe_json_dumps as _jinja_htmlsafe_dumps
  File "D:\Python_Project\Head_first\venv\lib\site-packages\jinja2\__init__.py", line 8, in <module>
    from .environment import Environment
  File "D:\Python_Project\Head_first\venv\lib\site-packages\jinja2\environment.py", line 16, in <module>
    from . import nodes
  File "D:\Python_Project\Head_first\venv\lib\site-packages\jinja2\nodes.py", line 1199, in <module>
    def _failing_new(*args: t.Any, **kwargs: t.Any) -> t.NoReturn:
AttributeError: module 'typing' has no attribute 'NoReturn'

实在难得折腾了，删除以3.6版本为基础的python虚拟环境，重新弄了3.10的虚拟环境

瞬间解决