如何把字符串转化成时间

import datetime

dateTime_p = datetime.datetime.now() 

date_p = dateTime_p.date()

print(dateTime_p) #2019-01-30 15:17:46.573139

print(date_p) #2019-01-30

#!/usr/bin/env python3

import datetime

date_p = datetime.datetime.now().date()

str_p = str(date_p)

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

print(str_p,type(str_p)) #2019-01-30 <class 'str'>

import datetime

str_p = '2019-01-30 15:29:08'

dateTime_p = datetime.datetime.strptime(str_p,'%Y-%m-%d %H:%M:%S')

print(dateTime_p) # 2019-01-30 15:29:08