Code:
# -*- coding:utf-8 -*-
__author__ = 'yangxin'
import datetime
today = datetime.date.today()
print today
year_today = str(today)[0:4]
month_today = str(today)[5:7]
day_today = str(today)[8:10]
print year_today
print int(month_today)
print int(day_today)
yesterday = today - datetime.timedelta(days = 1)
print yesterday
year_yes = str(yesterday)[0:4]
month_yes = str(yesterday)[5:7]
day_yes = str(yesterday)[8:10]
print year_yes
print int(month_yes)
print int(day_yes)
Result: