python和mysql工作台中两个日期的区别

Question

我将日期存储在 MySQL db 中，我已经使用 python 获取它并添加了 15 天（成功完成），现在我必须获取该日期与当前日期的差异

import mysql.connector
import datetime
mydb = mysql.connector.connect(host="localhost", user="root", password="afif123", db="library")
mycursor = mydb.cursor()
date_query = '''SELECT Date from issued_book WHERE Username = 'afif' AND  Book_Code = 12'''
mycursor.execute(date_query)
date_fetch = mycursor.fetchall()
date1 = date_fetch[0]
print(date1)
d1 = date1[0]
diff = d1 + datetime.timedelta(days=15)
dc = diff.strftime('%Y-%m-%d')
print("diff:", dc)
today1 = datetime.datetime.now().strftime('%Y-%m-%d')
print("today1:", today1)
day = dc - today1
print(day)

我需要天数（int）的差异，所以我可以计算罚款

错误显示如下：

Traceback（最近一次调用最后一次）：

(datetime.datetime(2019, 4, 18, 15, 47, 51),)

差异：2019-05-03

文件“C:/Users/shaik/Desktop/lib/d.py”，第 16 行，在

今天1：2019-04-28

day = dc - 今天1

TypeError: 不支持的操作数类型 -: 'str' 和 'str'

进程以退出代码 1 结束

Answer 1

要计算差异，您必须使用 datetime.datetime 对象。然后当你减去时，你会得到一个 timedelta 对象。

import mysql.connector
import datetime
mydb = mysql.connector.connect(host="localhost", user="root", password="afif123", db="library")
mycursor = mydb.cursor()
date_query = '''SELECT Date from issued_book WHERE Username = 'afif' AND  Book_Code = 12'''
mycursor.execute(date_query)
date_fetch = mycursor.fetchall()
date1 = date_fetch[0]
print(date1)
d1 = date1[0]
diff = d1 + datetime.timedelta(days=15)
dc = diff.strftime('%Y-%m-%d')
print("diff:", dc)

# Below is the updated piece from your code
today1 = datetime.datetime.today() 
print("today1:", today1.strftime('%Y-%m-%d'))
delta = diff - today1
print(delta.days) 

希望这会有所帮助！