如何把字符串转化成时间

import datetime

dateTime_p = datetime.datetime.now()

str_p = datetime.datetime.strftime(dateTime_p,'%Y-%m-%d')

print(dateTime_p) # 2019-01-30 15:36:19.415157

#!/usr/bin/env python3

import datetime

str_p = '2019-01-30'

date_p = datetime.datetime.strptime(str_p,'%Y-%m-%d').date()

print(date_p,type(date_p)) # 2019-01-30 <class 'datetime.date'>

#!/usr/bin/env python3

import datetime

# today = datetime.datetime.today()

today = datetime.datetime.today().date()

yestoday = today + datetime.timedelta(days=-1)

tomorrow = today + datetime.timedelta(days=1)

print(today) # 2019-01-30

print(yestoday)# 2019-01-29

print(tomorrow)# 2019-01-31