pip3 install jpholiday

import jpholiday

jpholiday.is_holiday(datetime.date(year, month, day)
jpholiday.is_holiday_name(datetime.date(year, month, day)
jpholiday.year_holidays(year)
jpholiday.month_holidays(year, month)
jpholiday.between(datetime.date(year, month, day), datetime(year, month, day))