Python Date/Time modules

`datetime`	Can provide time difference calculations >>> # dates are easily constructed and formatted >>> from datetime import date >>> now = date.today() >>> now datetime.date(2003, 12, 2) >>> now.strftime("%m-%d-%y. %d %b %Y is a %A on the %d day of %B.") '12-02-03. 02 Dec 2003 is a Tuesday on the 02 day of December.' >>> # dates support calendar arithmetic >>> birthday = date(1964, 7, 31) >>> age = now - birthday >>> age.days 14368 Using strptime() >>> from datetime import datetime >>> >>> datetime.strptime('2016-01-01', '%Y-%m-%d') datetime.datetime(2016, 1, 1, 0, 0) >>> >>> datetime.strptime('03-01-2018', '%Y-%m-%d') Traceback (most recent call last):   File "", line 1, in   File "/usr/lib/python2.7/_strptime.py", line 332, in _strptime (data_string, format)) ValueError: time data '03-01-2018' does not match format '%Y-%m-%d' >>> >>> >>> datetime.strptime('2016-01-01', '%Y-%m-%d %H:%M:%S') Traceback (most recent call last):   File "", line 1, in   File "/usr/lib/python2.7/_strptime.py", line 332, in _strptime (data_string, format)) ValueError: time data '2016-01-01' does not match format '%Y-%m-%d %H:%M:%S' >>> >>> datetime.strptime('2016-01-01 04:16:34', '%Y-%m-%d %H:%M:%S') datetime.datetime(2016, 1, 1, 4, 16, 34)         >>> https://docs.python.org/3/library/datetime.html#datetime.datetime.strptime Managing time differences >>> a = timedelta(days=365) >>> b = timedelta(days=100) >>> a - b datetime.timedelta(265) >>> Callable methods on datetime >>> date = datetime.strptime('2018-03-18', '%Y-%m-%d') >>> >>> dir(date) ['add', 'class', 'delattr', 'dir', 'doc', 'eq', 'format', 'ge', 'getattribute', 'gt', 'hash', 'init', 'init_subclass', 'le', 'lt', 'ne', 'new', 'radd', 'reduce', 'reduce_ex', 'repr', 'rsub', 'setattr', 'sizeof', 'str', 'sub', 'subclasshook', 'astimezone', 'combine', 'ctime', 'date', 'day', 'dst', 'fold', 'fromordinal', 'fromtimestamp', 'hour', 'isocalendar', 'isoformat', 'isoweekday', 'max', 'microsecond', 'min', 'minute', 'month', 'now', 'replace', 'resolution', 'second', 'strftime', 'strptime', 'time', 'timestamp', 'timetuple', 'timetz', 'today', 'toordinal', 'tzinfo', 'tzname', 'utcfromtimestamp', 'utcnow', 'utcoffset', 'utctimetuple', 'weekday', 'year'] >>> >>> date.timestamp() 1521302400.0 >>>
`time`	Can do simple time operations and also include a sleep function. >>> import time >>> dir(time) ['CLOCK_MONOTONIC', 'CLOCK_MONOTONIC_RAW', 'CLOCK_PROCESS_CPUTIME_ID', 'CLOCK_REALTIME', 'CLOCK_THREAD_CPUTIME_ID', '_STRUCT_TM_ITEMS', '__doc__', '__loader__', '__name__', '__package__', '__spec__', 'altzone', 'asctime', 'clock', 'clock_getres', 'clock_gettime', 'clock_settime', 'ctime', 'daylight', 'get_clock_info', 'gmtime', 'localtime', 'mktime', 'monotonic', 'perf_counter', 'process_time', 'sleep', 'strftime', 'strptime', 'struct_time', 'time', 'timezone', 'tzname', 'tzset'] >>> time.localtime >>> time.localtime() time.struct_time(tm_year=2017, tm_mon=8, tm_mday=29, tm_hour=18, tm_min=20, tm_sec=35, tm_wday=1, tm_yday=241, tm_isdst=0) >>> >>> >>> >>> time.sleep(3) >>>
`timeit`	Measures speed of small code snippets. >>> from timeit import Timer >>> Timer('t=a; a=b; b=t', 'a=1; b=2').timeit() 0.57535828626024577 >>> Timer('a,b = b,a', 'a=1; b=2').timeit() 0.54962537085770791 For larger codes, use `profile` and `pstats`