cannot import pyLDAvis - ModuleNotFoundError: No module named '_contextvars'

Question

I am trying to import pyLDAvis but it gives the error ModuleNotFoundError: No module named '_contextvars' although I installed both pyLDAvis and contextvars. The error is as follows

Traceback (most recent call last):
  File "C:/Users/ebru/Documents/Arda Docs/Mydocs/ITLS/Research/Tüpraş/Python Codes/Tupras_NLPv04.py", line 249, in <module>
    import pyLDAvis
  File "C:\Users\ebru\PycharmProjects\Tuprasv01\venv\lib\site-packages\pyLDAvis\__init__.py", line 44, in <module>
    from ._display import *
  File "C:\Users\ebru\PycharmProjects\Tuprasv01\venv\lib\site-packages\pyLDAvis\_display.py", line 7, in <module>
    import jinja2
  File "C:\Users\ebru\PycharmProjects\Tuprasv01\venv\lib\site-packages\jinja2\__init__.py", line 82, in <module>
    _patch_async()
  File "C:\Users\ebru\PycharmProjects\Tuprasv01\venv\lib\site-packages\jinja2\__init__.py", line 78, in _patch_async
    from jinja2.asyncsupport import patch_all
  File "C:\Users\ebru\PycharmProjects\Tuprasv01\venv\lib\site-packages\jinja2\asyncsupport.py", line 13, in <module>
    import asyncio
  File "C:\Users\ebru\AppData\Local\Programs\Python\Python37-32\lib\asyncio\__init__.py", line 8, in <module>
    from .base_events import *
  File "C:\Users\ebru\AppData\Local\Programs\Python\Python37-32\lib\asyncio\base_events.py", line 39, in <module>
    from . import events
  File "C:\Users\ebru\AppData\Local\Programs\Python\Python37-32\lib\asyncio\events.py", line 14, in <module>
    import contextvars
  File "C:\Users\ebru\AppData\Local\Programs\Python\Python37-32\lib\contextvars.py", line 1, in <module>
    from _contextvars import Context, ContextVar, Token, copy_context
ModuleNotFoundError: No module named '_contextvars'

I tried to delete the underscore in contextvars.py but it did not work.

Plotting tools

import pyLDAvis
import pyLDAvis.sklearn

Answer 1

According to https://github.com/axnsan12/drf-yasg/issues/362#issuecomment-494360308 , this problem might result from virtualenv not upgrading to the Python version you have installed.

Also, 3.7.4 has been released & includes changes related to Context Variables. Maybe upgrading to that helps?