Hi,
After I updated Mac OS Big Sir to 11.5.2 on my MacBook Air (M1 2021), I’m not able to import zipline and pyfolio.
Below is error message. I can’t understand if this error rerates to OS update.
> Python 3.8.10 | packaged by conda-forge | (default, May 10 2021, 22:58:09) 
> [Clang 11.1.0 ] on darwin
> Type "help", "copyright", "credits" or "license" for more information.
> >>> import pyfolio
> Traceback (most recent call last):
>   File "<stdin>", line 1, in <module>
>   File "/Users/pm/opt/miniconda3/envs/ml4t/lib/python3.8/site-packages/pyfolio/__init__.py", line 1, in <module>
>     from . import utils
>   File "/Users/pm/opt/miniconda3/envs/ml4t/lib/python3.8/site-packages/pyfolio/utils.py", line 26, in <module>
>     from . import pos
>   File "/Users/pm/opt/miniconda3/envs/ml4t/lib/python3.8/site-packages/pyfolio/pos.py", line 20, in <module>
>     from zipline.assets import Equity, Future
>   File "/Users/pm/opt/miniconda3/envs/ml4t/lib/python3.8/site-packages/zipline/__init__.py", line 21, in <module>
>     from trading_calendars import get_calendar
>   File "/Users/pm/opt/miniconda3/envs/ml4t/lib/python3.8/site-packages/trading_calendars/__init__.py", line 16, in <module>
>     from .trading_calendar import TradingCalendar
>   File "/Users/pm/opt/miniconda3/envs/ml4t/lib/python3.8/site-packages/trading_calendars/trading_calendar.py", line 33, in <module>
>     from .calendar_helpers import (
>   File "/Users/pm/opt/miniconda3/envs/ml4t/lib/python3.8/site-packages/trading_calendars/calendar_helpers.py", line 6, in <module>
>     NP_NAT = np.array([pd.NaT], dtype=np.int64)[0]
> TypeError: int() argument must be a string, a bytes-like object or a number, not 'NaTType'
> >>> exit()