Python中的datetime包与time包包和模块详情

# coding:utf-8

from datetime import timedelta

if __name__ == '__main__':
    # 常用参数 hours:小时 days:天 seconds:秒 milliseconds:毫秒
    delta = timedelta(hours=2)
    print(delta)  # 2:00:00
    print(type(delta))  # <class 'datetime.timedelta'>

# coding:utf-8

from datetime import timedelta, timezone

if __name__ == '__main__':
    delta = timedelta(hours=2)
    zone = timezone(delta)  #配合timedelta创建时区对象
    print(zone)  # UTC+02:00
    print(type(zone))  # <class 'datetime.timezone'>

datetime.now(timezone) 获取当前时间datetime对象
# coding:utf-8

from datetime import timedelta, timezone, datetime

if __name__ == '__main__':
    '''
    获取当前时间，可以获取指定时区的当前时间
    datetime.now(timezone)
    '''
    now = datetime.now()
    print(now)  # 2022-02-23 13:59:59.224286
    print(type(now))  # <class 'datetime.datetime'>

    # 设置指定时区的当前时间
    print(datetime.now((timezone(timedelta(hours=9)))))  # 2022-02-23 14:59:59.224286+09:00

# coding:utf-8

from datetime import datetime

if __name__ == '__main__':
    '''
    datetime.strftime(fmt)
    将时间对象转换成字符串
    fmt:格式化标准，由格式符组成
    常用格式符(年:%Y,月:%m,日:%D,时:%H,分:%M,秒:%S)
    '''
    now = datetime.now()
    print(now.strftime('%Y-%m-%d %H:%M:%S'))  # 2022-02-23 14:04:24

# coding:utf-8
from datetime import datetime

if __name__ == '__main__':
    '''
    datetime.strptime(date_string,fmt)
    将字符串转换成时间对象，要求date_string的格式完全匹配fmt格式化标准
    '''
    time_obj = datetime.strptime('2022-2-22', '%Y-%m-%d')
    # datetime.strptime('2022-2-22', '%Y-%m-%d %H') Error date_string 中不存在小时而fmt中要求有小时
    print(datetime.strptime('2022-2-22 14', '%Y-%m-%d %H'))  # 2022-02-22 14:00:00
    print(time_obj)  # 2022-02-22 00:00:00
    print(type(time_obj))  # <class 'datetime.datetime'>

# coding:utf-8

from datetime import datetime

if __name__ == '__main__':
    '''
    datetime.timestamp(datetime_obj) 
    datetime_obj:datetime 时间对象
    返回 float
    '''
    print(datetime.timestamp(datetime.now()))  # 1645598565.715

# coding:utf-8

from datetime import datetime, timedelta, timezone

if __name__ == '__main__':
    '''
    datetime.fromtimestamp(t)
    t:秒级时间戳 float类型
    返回:datetime时间对象
    '''
    datetime_obj = datetime.fromtimestamp(1645598565.715)
    print(datetime_obj)  # 2022-02-23 14:42:45.715000
    print(type(datetime_obj))  # <class 'datetime.datetime'>

# coding:utf-8

from datetime import datetime, timedelta, timezone

if __name__ == '__main__':
    now = datetime.now()
    fmt = '%Y-%m-%d %H:%M:%S'
    print(now.strftime(fmt))  # 2022-02-23 15:07:01

    # 3小时后时间
    print((now + timedelta(hours=3)).strftime(fmt))  # 2022-02-23 18:07:01

    # 3小时前时间
    print((now - timedelta(hours=3)).strftime(fmt))  # 2022-02-23 12:07:01
    print((now + timedelta(hours=-3)).strftime(fmt))  # 2022-02-23 12:07:01

    # 建议timedelta的参数都使用正数(容易理解)

# coding:utf-8

import time

if __name__ == '__main__':
    print(time.time())  # 1645667203.7236724

# coding:utf-8

import time

if __name__ == '__main__':
    # second 不填，则默认当前的时间戳
    t = time.localtime(time.time())
    t2 = time.localtime()
    print(t)  # time.struct_time(tm_year=2022, tm_mon=2, tm_mday=24, tm_hour=10, tm_min=10, tm_sec=8, tm_wday=3, tm_yday=55, tm_isdst=0)
    print(t2)  # time.struct_time(tm_year=2022, tm_mon=2, tm_mday=24, tm_hour=10, tm_min=10, tm_sec=8, tm_wday=3, tm_yday=55, tm_isdst=0)
    print(type(t))  # <class 'time.struct_time'>
    print(type(t2))  # <class 'time.struct_time'>

# coding:utf-8

import time

if __name__ == '__main__':
    """
    time.strftime(fmt,time_obj)
    fmt:格式化标准 参考 datetime.strftime(fmt)
    time_obj:time时间对象，不填默认是当前日期的time时间对象
    """
    t = time.localtime(time.time() + 3600)
    print(time.strftime('%Y-%m-%d %H:%M:%S'))  # 2022-02-24 10:16:17
    print(time.strftime('%Y-%m-%d %H:%M:%S', t))  # 2022-02-24 11:16:17

# coding:utf-8

import time

if __name__ == '__main__':
    """
    time.strptime(time_string,fmt)
    参考 datetime.strptime(date_string,fmt)
    time_string:时间字符串
    fmt:格式化标准
    """
    fmt = '%Y-%m-%d %H:%M:%S'
    t = time.strftime(fmt, time.localtime())
    print(t)  # 2022-02-24 10:25:17
    print(time.strptime(t, fmt))  # time.struct_time(tm_year=2022, tm_mon=2, tm_mday=24, tm_hour=10, tm_min=25, tm_sec=40, tm_wday=3, tm_yday=55, tm_isdst=-1)

# coding:utf-8

import time

if __name__ == '__main__':
    print(time.time())  # 1645670183.6567423
    time.sleep(2)
    print(time.time())  # 1645670185.6708047