• python time模块


      1 import time
      2 
      3 # 2种表示时间的方法:
      4 # (1)时间戳,从1970.1.1开始
      5 # (2)一个9个整数的元组
      6 #    这个元组内容:
      7 #       year (including century, e.g. 1998)
      8 #       month (1-12)
      9 #       day (1-31)
     10 #       hours (0-23)
     11 #       minutes (0-59)
     12 #       seconds (0-59)
     13 #       weekday (0-6, Monday is 0)
     14 #       Julian day (day in the year, 1-366)
     15 #       DST (Daylight Savings Time) flag (-1, 0 or 1)
     16 #          1 if summer time is in effect, 0 if not, and -1 if unknown
     17 
     18 
     19 # FUNCTIONS
     20 """
     21     time(...)
     22         time() -> floating point number
     23 
     24         Return the current time in seconds since the Epoch.
     25         Fractions of a second may be present if the system clock provides them.
     26         本地的当前时间的时间戳
     27 """
     28 print(time.time())
     29 
     30 """
     31     localtime(...)
     32         localtime([seconds]) -> (tm_year,tm_mon,tm_mday,tm_hour,tm_min,
     33                                   tm_sec,tm_wday,tm_yday,tm_isdst)
     34 
     35         Convert seconds since the Epoch to a time tuple expressing local time.
     36         When 'seconds' is not passed in, convert the current time instead.
     37         没有参数时本地的当前时间的元组形式
     38 """
     39 print(time.localtime())
     40 
     41 """
     42     gmtime(...)
     43         gmtime([seconds]) -> (tm_year, tm_mon, tm_mday, tm_hour, tm_min,
     44                                tm_sec, tm_wday, tm_yday, tm_isdst)
     45 
     46         Convert seconds since the Epoch to a time tuple expressing UTC (a.k.a.
     47         GMT).  When 'seconds' is not passed in, convert the current time instead.
     48 
     49         If the platform supports the tm_gmtoff and tm_zone, they are available as
     50         attributes only.
     51 """
     52 print(time.gmtime(time.time()))
     53 
     54 
     55 """
     56     mktime(...)
     57         mktime(tuple) -> floating point number
     58 
     59         Convert a time tuple in local time to seconds since the Epoch.
     60         Note that mktime(gmtime(0)) will not generally return zero for most
     61         time zones; instead the returned value will either be equal to that
     62         of the timezone or altzone attributes on the time module.
     63 """
     64 print(time.mktime(time.localtime()))
     65 
     66 
     67 """
     68     asctime(...)
     69         asctime([tuple]) -> string
     70 
     71         Convert a time tuple to a string, e.g. 'Sat Jun 06 16:26:11 1998'.
     72         When the time tuple is not present, current time as returned by localtime()
     73         is used.
     74         tuple转字符串,默认是当前时间
     75 """
     76 print(time.asctime())   # Thu Jan 18 16:36:07 2018
     77 
     78 """
     79     ctime(...)
     80         ctime(seconds) -> string
     81 
     82         Convert a time in seconds since the Epoch to a string in local time.
     83         This is equivalent to asctime(localtime(seconds)). When the time tuple is
     84         not present, current time as returned by localtime() is used.
     85         时间戳转字符串,默认是当前时间
     86 """
     87 print(time.ctime())
     88 
     89 """
     90     strftime(...)
     91         strftime(format[, tuple]) -> string
     92 
     93         Convert a time tuple to a string according to a format specification.
     94         See the library reference manual for formatting codes. When the time tuple
     95         is not present, current time as returned by localtime() is used.
     96 
     97         Commonly used format codes:
     98 
     99         %Y  Year with century as a decimal number.
    100         %m  Month as a decimal number [01,12].
    101         %d  Day of the month as a decimal number [01,31].
    102         %H  Hour (24-hour clock) as a decimal number [00,23].
    103         %M  Minute as a decimal number [00,59].
    104         %S  Second as a decimal number [00,61].
    105         %z  Time zone offset from UTC.      +0800                    
    106         %a  Locale's abbreviated weekday name.      Thu
    107         %A  Locale's full weekday name.      Thursday
    108         %b  Locale's abbreviated month name.     Jan
    109         %B  Locale's full month name.     January
    110         %c  Locale's appropriate date and time representation. Thu Jan 18 16:53:35 2018
    111         %I  Hour (12-hour clock) as a decimal number [01,12].  04 
    112         %p  Locale's equivalent of either AM or PM.            PM
    113 
    114         Other codes may be available on your platform.  See documentation for
    115         the C library strftime function.
    116         格式化元组到字符串
    117 """
    118 print(time.strftime('%Y-%m-%d %H:%M:%S', time.localtime()))
    119 
    120 """
    121     strptime(...)
    122         strptime(string, format) -> struct_time
    123 
    124         Parse a string to a time tuple according to a format specification.
    125         See the library reference manual for formatting codes (same as
    126         strftime()).
    127 
    128         Commonly used format codes:
    129 
    130         %Y  Year with century as a decimal number.
    131         %m  Month as a decimal number [01,12].
    132         %d  Day of the month as a decimal number [01,31].
    133         %H  Hour (24-hour clock) as a decimal number [00,23].
    134         %M  Minute as a decimal number [00,59].
    135         %S  Second as a decimal number [00,61].
    136         %z  Time zone offset from UTC.
    137         %a  Locale's abbreviated weekday name.
    138         %A  Locale's full weekday name.
    139         %b  Locale's abbreviated month name.
    140         %B  Locale's full month name.
    141         %c  Locale's appropriate date and time representation.
    142         %I  Hour (12-hour clock) as a decimal number [01,12].
    143         %p  Locale's equivalent of either AM or PM.
    144 
    145         Other codes may be available on your platform.  See documentation for
    146         the C library strftime function.
    147         字符串到元组
    148 """
    149 #
    150 print(time.strptime('2018-01-18 16:55:01', '%Y-%m-%d %H:%M:%S'))
    151 print(time.strptime('Thu Jan 18 16:55:56 2018', '%c'))
    152 
    153 """
    154     sleep(...)
    155         sleep(seconds)
    156 
    157         Delay execution for a given number of seconds.  The argument may be
    158         a floating point number for subsecond precision.
    159 """
    160 """
    161     clock(...)
    162         clock() -> floating point number
    163 
    164         Return the CPU time or real time since the start of the process or since
    165         the first call to clock().  This has as much precision as the system
    166         records.
    167 """
    168 def func():
    169     sum = 0
    170     for i in range(1000):
    171         sum = sum + 1
    172         time.sleep(0.01)
    173 
    174 t0 = time.clock()
    175 p0 = time.time()
    176 print(t0, p0)
    177 func()
    178 t1 = time.clock()
    179 p1 = time.time()
    180 print(t1, p1)
    181 print(t1-t0, p1-p0)   # 0.08869099999999999 10.986821174621582
    182 # linux端,clock只统计cpu运行的时间,执行语句,sleep不统计。windows不一样
    183 
    184 """
    185     get_clock_info(...)
    186         get_clock_info(name: str) -> dict
    187 
    188         Get information of the specified clock.
    189 """
    190 print(time.get_clock_info('clock'))
    191 print(time.get_clock_info('monotonic'))
    192 print(time.get_clock_info('perf_counter'))
    193 print(time.get_clock_info('process_time'))
    194 print(time.get_clock_info('time'))
    195 
    196 
    197 """
    198     monotonic(...)
    199         monotonic() -> float
    200 
    201         Monotonic clock, cannot go backward.
    202         系统启动,开启的一个时钟,也就是系统开启时间
    203 """
    204 
    205 
    206 """
    207     perf_counter(...)
    208         perf_counter() -> float
    209 
    210         Performance counter for benchmarking.
    211         系统运行时间
    212 """
    213 
    214 
    215 """
    216     process_time(...)
    217         process_time() -> float
    218 
    219         Process time for profiling: sum of the kernel and user-space CPU time.
    220 """
    221 def func():
    222     sum = 0
    223     for i in range(1000):
    224         sum = sum + 1
    225         time.sleep(0.01)
    226 
    227 t0 = time.process_time()
    228 p0 = time.time()
    229 print(t0, p0)
    230 func()
    231 t1 = time.process_time()
    232 p1 = time.time()
    233 print(t1, p1)
    234 print(t1-t0, p1-p0)   # 0.08869099999999999 10.986821174621582
    235 # 统计内核和用户空间占用cpu的时间
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  • 原文地址:https://www.cnblogs.com/gundan/p/8311183.html
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