TypeError: descriptor '__subclasses__' of 'type' object needs an argument while trying to import rasa_core

python python-3.x rasa-nlu rasa-core
Rohit Nair picture Rohit Nair · May 2, 2019 · Viewed 15.9k times · Source

Trying to run a program that runs perfectly fine on my local machine, but on AWS I'm getting: TypeError: descriptor '__subclasses__' of 'type' object needs an argument. My pip3 isn't upgraded to the latest version, but that shouldn't be causing an issue since I have downloaded the latest version of rasa_core.

Tried re-installing rasa_core using pip3 -u rasa_core, also tried appending the command with sudo. This is the error I get, can someone please help

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/ubuntu/.local/lib/python3.5/site-packages/rasa_core/__init__.py", line 5, in <module>
    from rasa_core.train import train
  File "/home/ubuntu/.local/lib/python3.5/site-packages/rasa_core/train.py", line 11, in <module>
    from rasa_core.domain import TemplateDomain
  File "/home/ubuntu/.local/lib/python3.5/site-packages/rasa_core/domain.py", line 12, in <module>
    from rasa_core.actions import Action, action
  File "/home/ubuntu/.local/lib/python3.5/site-packages/rasa_core/actions/__init__.py", line 1, in <module>
    from rasa_core.actions.action import Action
  File "/home/ubuntu/.local/lib/python3.5/site-packages/rasa_core/actions/action.py", line 9, in <module>
    from rasa_core import events
  File "/home/ubuntu/.local/lib/python3.5/site-packages/rasa_core/events/__init__.py", line 73, in <module>
    class Event(object):
  File "/home/ubuntu/.local/lib/python3.5/site-packages/rasa_core/events/__init__.py", line 94, in Event
    default: Optional[Type['Event']] = None
  File "/usr/lib/python3.5/typing.py", line 649, in __getitem__
    return Union[arg, type(None)]
  File "/usr/lib/python3.5/typing.py", line 552, in __getitem__
    dict(self.__dict__), parameters, _root=True)
  File "/usr/lib/python3.5/typing.py", line 512, in __new__
    for t2 in all_params - {t1} if not isinstance(t2, TypeVar)):
  File "/usr/lib/python3.5/typing.py", line 512, in <genexpr>
    for t2 in all_params - {t1} if not isinstance(t2, TypeVar)):
  File "/usr/lib/python3.5/typing.py", line 1077, in __subclasscheck__
    if super().__subclasscheck__(cls):
  File "/usr/lib/python3.5/abc.py", line 225, in __subclasscheck__
    for scls in cls.__subclasses__():
TypeError: descriptor '__subclasses__' of 'type' object needs an argument

Can someone please help.

Answer

Ella Rohm-Ensing picture Ella Rohm-Ensing · May 6, 2019

If your python 3.5 is version 3.5.3 or below, I believe upgrading should fix it. See a relevant issue here

From the relevant error in typing:

typing will only get upgraded with Python if you are on Python 3.5+. Since this issue was fixed in August 2016, I believe any 3.5 release above 3.5.3 should work.

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