Since, Thanksgiving is always a Thursday AND Black Friday is always a day later, you can identify Thankgiving Day directly (via holidays package) and then just add a day:

from datetime import datetime, timedelta
import holidays

us_holidays = holidays.UnitedStates(years=2020)
black_friday = us_holidays.get_named('Thanksgiving')[0] + timedelta(days=1)

print(black_friday)