Superset安装抛出异常No module named 'wtforms_json'

问题现象

在安装Superset执行命令superset db upgrade时抛出如下异常：

Traceback (most recent call last):
  File "/home/alphatan/anaconda3/envs/beacon-library/bin/superset", line 18, in 
    from superset.cli import superset
  File "/home/alphatan/anaconda3/envs/beacon-library/lib/python3.6/site-packages/superset/__init__.py", line 21, in 
    from superset.app import create_app
  File "/home/alphatan/anaconda3/envs/beacon-library/lib/python3.6/site-packages/superset/app.py", line 21, in 
    import wtforms_json
ModuleNotFoundError: No module named 'wtforms_json'

解决方案

pip install WTForms-JSON