20.time与datetime模块

Posted 2020-09-19

time与datetime模块

 

• 时间戳               1970年1月1日之后的秒，即：time.time()
• 格式化的字符串    2014-11-11 11:11，    即：time.strftime(‘%Y-%m-%d‘)
• 结构化时间          元组包含了：年、日、星期等... time.struct_time    即：time.localtime()

import time

time.sleep(5)
‘‘‘
程序停止5秒
‘‘‘
print(time.time())
‘‘‘
时间戳：1495539499.9574285
‘‘‘

print(time.ctime())                   # 字符串格式
‘‘‘
Tue May 23 19:38:19 2017
‘‘‘
print(time.ctime(time.time()-86400))  # 减去一天的秒数，将时间戳转换成字符串时间
‘‘‘
Mon May 22 19:38:19 2017
‘‘‘

# 将时间戳转换成时间对象格式
time_obj = time.gmtime(time.time())
print(time_obj)
‘‘‘
time.struct_time(tm_year=2017, tm_mon=5, tm_mday=23, tm_hour=11, tm_min=38, tm_sec=19, tm_wday=1, tm_yday=143, tm_isdst=0)
‘‘‘
print(time_obj.tm_year)
‘‘‘
2017
‘‘‘
print(str(time_obj.tm_year) + ‘-‘ + str(time_obj.tm_mon) + ‘-‘ + str(time_obj.tm_mday))
‘‘‘
2017-5-23
‘‘‘

# 字符串格式化
print("%s-%s-%s %s:%s" % (time_obj.tm_year, time_obj.tm_mon, time_obj.tm_mday, time_obj.tm_hour, time_obj.tm_min))
‘‘‘
2017-5-23 11:38
‘‘‘
print("%d-%f-%d %d:%d" % (time_obj.tm_year, time_obj.tm_mon, time_obj.tm_mday, time_obj.tm_hour, time_obj.tm_min))
‘‘‘
2017-5.000000-23 11:38
%d只能接收整型数剧，但是%s都可以各种类型的数据
‘‘‘

# 本地时间  输出一个时间对象
print(time.localtime(time.time()))
‘‘‘
time.struct_time(tm_year=2017, tm_mon=5, tm_mday=23, tm_hour=19, tm_min=38, tm_sec=19, tm_wday=1, tm_yday=143, tm_isdst=0)
‘‘‘

# 将时间对象转换成时间戳
print(time.mktime(time.localtime()))
‘‘‘
1495539499.0
‘‘‘

# 将时间对象格式转换成指定的字符串格式
print(time.strftime("%Y-%m-%d %H:%M:%S", time.gmtime()))
‘‘‘
2017-05-23 11:38:19
‘‘‘
print(time.strftime("%Y-%m-%d %H:%M:%S", time.localtime()))
‘‘‘
2017-05-23 19:38:19
‘‘‘

# 将字符串格式转换成时间对象格式
print(time.strptime("2016-01-28", "%Y-%m-%d"))
‘‘‘
time.struct_time(tm_year=2016, tm_mon=1, tm_mday=28, tm_hour=0, tm_min=0, tm_sec=0, tm_wday=3, tm_yday=28, tm_isdst=-1)
‘‘‘


import datetime

print(datetime.date.today())
‘‘‘
2017-05-23
‘‘‘
print(datetime.date.fromtimestamp(time.time()-664000000))
‘‘‘
1996-05-08
‘‘‘
current_time = datetime.datetime.now()
print(current_time)
‘‘‘
2017-05-23 19:38:20.001431
‘‘‘
print(current_time.timetuple()) # 返回时间对象格式
‘‘‘
time.struct_time(tm_year=2017, tm_mon=5, tm_mday=23, tm_hour=19, tm_min=38, tm_sec=20, tm_wday=1, tm_yday=143, tm_isdst=-1)
‘‘‘
print(current_time.replace(2014, 12, 12))# 输出当前时间，指定值被替换
‘‘‘
2014-12-12 19:38:20.001431
‘‘‘
str_to_date = datetime.datetime.strptime("21/11/06 16:30", "%d/%m/%y %H:%M")#将字符串转换成日期的字符串格式
print(str_to_date)
‘‘‘
2006-11-21 16:30:00
‘‘‘

# 时间的加减  用得很多
new_date0 = datetime.datetime.now() + datetime.timedelta(days=-10)  #减10天
‘‘‘

‘‘‘
new_date1 = datetime.datetime.now() + datetime.timedelta(hours=-10) #减10个小时
‘‘‘

‘‘‘
new_date2 = datetime.datetime.now() + datetime.timedelta(seconds=-10) # 减10秒
‘‘‘

‘‘‘