问尝试导入pandas_market_calender时出现NP_NAT错误

EN

import sys
sys.path.append("../")
from datetime import time
import pandas as pd
import pandas_market_calendars as mcal

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "C:\Users\User\Anaconda3\envs\py39\lib\site-packages\pandas_market_calendars\__init__.py", line 19, in <module>
    from .calendar_registry import get_calendar, get_calendar_names
  File "C:\Users\User\Anaconda3\envs\py39\lib\site-packages\pandas_market_calendars\calendar_registry.py", line 21, in <module>
    from .exchange_calendars_mirror import *
  File "C:\Users\User\Anaconda3\envs\py39\lib\site-packages\pandas_market_calendars\exchange_calendars_mirror.py", line 9, in <module>
    import exchange_calendars
  File "C:\Users\User\Anaconda3\envs\py39\lib\site-packages\exchange_calendars\__init__.py", line 16, in <module>
    from .calendar_utils import (
  File "C:\Users\User\Anaconda3\envs\py39\lib\site-packages\exchange_calendars\calendar_utils.py", line 3, in <module>
    from .always_open import AlwaysOpenCalendar
  File "C:\Users\User\Anaconda3\envs\py39\lib\site-packages\exchange_calendars\always_open.py", line 5, in <module>
    from .exchange_calendar import ExchangeCalendar
  File "C:\Users\User\Anaconda3\envs\py39\lib\site-packages\exchange_calendars\exchange_calendar.py", line 27, in <module>
    from .calendar_helpers import (
  File "C:\Users\User\Anaconda3\envs\py39\lib\site-packages\exchange_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