使用 全新安装后pip install apache-airflow，任何运行气流的尝试都会以 python 导入错误结束：
Traceback (most recent call last):
File "/Users/\*/env/bin/airflow", line 26, in <module> from airflow.bin.cli import CLIFactory
File "/Users/\*/env/lib/python3.7/site-packages/airflow/bin/cli.py", line 70, in <module> from airflow.www.app import (cached_app, create_app)
File "/Users/\*/env/lib/python3.7/site-packages/airflow/www/app.py", line 26, in <module> from flask_wtf.csrf import CSRFProtect
File "/Users/\*/env/lib/python3.7/site-packages/flask_wtf/__init__.py", line 17, in <module> from .recaptcha import \*
File "/Users/\*/env/lib/python3.7/site-packages/flask_wtf/recaptcha/__init__.py", line 2, in <module> from .fields import \*
File "/Users/\*/env/lib/python3.7/site-packages/flask_wtf/recaptcha/fields.py", line 3, in <module> from . import widgets
File "/Users/\*/env/lib/python3.7/site-packages/flask_wtf/recaptcha/widgets.py", line 5, in <module> …