ImportError: cannot import name 'parse_rule' from 'werkzeug.routing' 解决办法

问题描述

当在其他系统上运行Flask工程时报错：

Error: While importing 'app', an ImportError was raised:

Traceback (most recent call last):
  File "c:\users\User\appdata\local\programs\python\python39\lib\site-packages\flask\cli.py", line 214, in locate_app
    __import__(module_name)
  File "C:\Users\User\Desktop\Projekt\app\__init__.py", line 3, in <module>
    from flask_restx import Namespace, Api
  File "c:\users\User\appdata\local\programs\python\python39\lib\site-packages\flask_restx\__init__.py", line 5, in <module>
  File "c:\users\User\appdata\local\programs\python\python39\lib\site-packages\flask_restx\api.py", line 50, in <module>
    from .swagger import Swagger
  File "c:\users\User\appdata\local\programs\python\python39\lib\site-packages\flask_restx\swagger.py", line 18, in <module>
    from werkzeug.routing import parse_rule
ImportError: cannot import name 'parse_rule' from 'werkzeug.routing' (c:\users\User\appdata\local\programs\python\python39\lib\site-packages\werkzeug\routing\__i
nit__.py)

工程依赖配置：

Flask~=2.1.2
psycopg2-binary==2.9.3
Flask-SQLAlchemy==2.5.1
flask-restx==0.5.1
qrcode~=7.3.1
PyPDF2==2.6.0
reportlab~=3.6.10
WTForms~=3.0.1
flask-bootstrap==3.3.7.1
flask-wtf==1.0.1

解决办法

在requirements.txt中添加:

werkzeug==2.1.2

根因分析

这是由于 parse_rule() 在最新版本的 werkzeug 上被标记为 :internal: 引起的，这会影响 flask-restx（以及许多其他功能，例如 flask-login）。

参考：
https://github.com/maxcountryman/flask-login/issues/686
https://github.com/python-restx/flask-restx/issues/460