Error when use an unittest.

[weqopy]

Here is the error information:

Traceback (most recent call last):
  File "manage.py", line 34, in <module>
    manager.run()
  File "/Users/...../venv/lib/python3.6/site-packages/flask_script/__init__.py", line 412, in run
    result = self.handle(sys.argv[0], sys.argv[1:])
  File "/Users/....../venv/lib/python3.6/site-packages/flask_script/__init__.py", line 350, in handle
    app_parser = self.create_parser(prog)
  File "/Users/....../venv/lib/python3.6/site-packages/flask_script/__init__.py", line 193, in create_parser
    command_parser = command.create_parser(name, func_stack=func_stack, parent=self)
AttributeError: 'function' object has no attribute 'create_parser'

In fact, this situation is same as https://segmentfault.com/q/1010000008301871.
Hope you can help me solve it, thanks.