python time datetime模块使用方法记录

import time
import datetime

#time datetime使用方法备份

print(time.clock())
#   4.665275792443746e-07       返回处理器时间
print(time.process_time())
#   0.0780005
print(time.time())
#   1488616321.8451998          返回当前时间戳 <class 'float'>
print(time.ctime())
#   Sat Mar  4 16:34:51 2017    格式化返回系统时间   <class 'str'>
print(time.ctime(887665))
#   Sun Jan 11 14:34:25 1970
print(time.ctime(time.time() - 60*60*24 ))
#   Fri Mar  3 16:39:17 2017    输出前一天
print(time.gmtime())
#   time.struct_time(tm_year=2017, tm_mon=3, tm_mday=4, tm_hour=8, tm_min=41, tm_sec=32, tm_wday=5, tm_yday=63, tm_isdst=0)
#   <class 'time.struct_time'>  格林尼治时间

print(time.localtime())
#   time.struct_time(tm_year=2017, tm_mon=3, tm_mday=4, tm_hour=16, tm_min=43, tm_sec=43, tm_wday=5, tm_yday=63, tm_isdst=0)
#   <class 'time.struct_time'>  当地时间
#   !!此时时间格式为struct_time

print(time.mktime(time.localtime()))
#   1488617178.0
#   将struct_time时间转化为float格式的时间

print(time.strftime("%Y-%m-%d %H:%M:%S",time.localtime(time.time() - 60*60*24)))
#   2017-03-03 16:59:15
#   将struct_time转化为字符串类型的时间
#   首先：time.time() 为float格式 time.localtime() 的输入格式即为float，输出格式为struct_time
#   time.strftime 又将struct_time 转化为字符串输出格式

print(time.strptime('2017-03-03 16:59:15',"%Y-%m-%d %H:%M:%S"))
#   time.struct_time(tm_year=2017, tm_mon=3, tm_mday=3, tm_hour=16, tm_min=59, tm_sec=15, tm_wday=4, tm_yday=62, tm_isdst=-1)
#   与strftime相反，输入为字符串格式，按照格式对应的字段转化为struct_time格式
#   '2017-03-03 16:59:15'与"%Y-%m-%d %H:%M:%S"是一一对应的。

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#   datetime
print(datetime.date.today(),type(datetime.date.today()))
#   2017-03-04     <class 'datetime.date'>
#   当前日期
print(datetime.date.fromtimestamp(time.time() - 60*60*24))
#   2017-03-03
#   将float格式的时间戳转化为<class 'datetime.date'>格式
current_time = datetime.datetime.now()
print(current_time)
#   2017-03-04 17:20:41.851214      当前时间
print(current_time.timetuple())
#   time.struct_time(tm_year=2017, tm_mon=3, tm_mday=4, tm_hour=17, tm_min=21, tm_sec=42, tm_wday=5, tm_yday=63, tm_isdst=-1)
#   将<class 'datetime.date'> 转化为 <class 'time.struct_time'>
print(current_time.replace(2012))
#   2012-03-04 17:29:53.446764
#   替换时间并输出
newtime = datetime.datetime.now() - datetime.timedelta(days=3)
print(datetime.datetime.now(),'\t',newtime)
#   2017-03-04 17:32:47.736732   2017-03-01 17:32:47.736732
#   days=3 为3天时间  -号则表示3天前