python_日期

一：格式化

from datetime import datetime, timedelta
	today = '2023-05-16'
	time1 = datetime.strptime(today, '%Y-%m-%d')  #字符串转为时间
    print(time1)   #结果 2023-05-16 00:00:00
    q = today.replace('-','')                    #去掉-
    print(q)       #结果 20230516
    a = time1.strftime('%Y-%m-%d %H-%M-%S')  #时间 转化 字符串
    print(a)       #结果2023-05-16 00-00-00
    b = time1 - timedelta(days=7)   #时间格式，往前7天
    c = b.strftime('%Y-%m-%d')
    print(b,c)      #结果2023-05-09 00:00:00   2023-05-09
    now7 = time1.month  # 月和日
    now8 = time1.day
    #结果 5 16

二：时间戳转化

    now = datetime.now()
    #结果 2023-05-16 12:01:06.407397
    now3 = now.date()
    #结果  2023-05-16
    day7 = now - timedelta(days=7)
    #结果  2023-05-09 12:01:06.407397
    
    # 此时时间戳
    now4 = int(datetime.now().timestamp())
    #结果 1684209666
    now5 = int(time1.timestamp())           #时间 转 时间戳
    #结果 1684166400
    now6 = datetime.fromtimestamp(now5)     #时间戳转为时间
    #结果 2023-05-16 00:00:00

三：上个月的日期

    today = datetime.now().date()
    first_day = today.replace(day=1)
    last_month = first_day - timedelta(days=1) #上个月最后一天
    first_month = last_month.replace(day=1)    #上个月第一天
    print(last_month, first_month)
    #结果 2023-04-30     2023-04-01