Python – Date & Time

 

Python – Date & Time, A Python software can cope with date and time in numerous approaches. Converting among date codecs is a not unusual chore for computers. Python’s time and calendar modules assist song dates and instances.

What is Tick?

Time durations are floating-factor numbers in units of seconds. Particular instants in time are expressed in seconds considering that 12:00am, January 1, 1970(epoch).

There is a famous time module to be had in Python which presents functions for operating with times, and for converting between representations. The function time.Time() returns the present day system time in ticks on the grounds that 12:00am, January 1, 1970(epoch).

Example

#!/usr/bin/python
import time;  # This is required to include time module.

ticks = time.time()
print "Number of ticks since 12:00am, January 1, 1970:", ticks

This could produce a end result some thing as follows −

Number of ticks since 12:00am, January 1, 1970: 7186862.73399

Date mathematics is straightforward to do with ticks. However, dates before the epoch can’t be represented in this form. Dates inside the far destiny also can’t be represented this way – the cutoff point is someday in 2038 for UNIX and Windows.

What is TimeTuple?

Many of Python’s time capabilities deal with time as a tuple of 9 numbers, as proven below −

Index	Field	Values
0	4-digit year	2008
1	Month	1 to 12
2	Day	1 to 31
3	Hour	0 to 23
4	Minute	0 to 59
5	Second	0 to 61 (60 or 61 are leap-seconds)
6	Day of Week	0 to 6 (0 is Monday)
7	Day of year	1 to 366 (Julian day)
8	Daylight savings	-1, 0, 1, -1 means library determines DST

The above tuple is equivalent to struct_time structure. This structure has following attributes −

Index	Attributes	Values
0	tm_year	2008
1	tm_mon	1 to 12
2	tm_mday	1 to 31
3	tm_hour	0 to 23
4	tm_min	0 to 59
5	tm_sec	0 to 61 (60 or 61 are leap-seconds)
6	tm_wday	0 to 6 (0 is Monday)
7	tm_yday	1 to 366 (Julian day)
8	tm_isdst	-1, 0, 1, -1 means library determines DST

Getting current time

Python – Date & Time, To translate a time instantaneous from a seconds for the reason that epoch floating-point value into a time-tuple, bypass the floating-factor cost to a feature (e.G., localtime) that returns a time-tuple with all nine objects valid.

#!/usr/bin/python
import time;

localtime = time.localtime(time.time())
print "Local current time :", localtime

This could produce the subsequent result, which may be formatted in some other presentable form −

Local current time : time.struct_time(tm_year=2013, tm_mon=7, 
tm_mday=17, tm_hour=21, tm_min=26, tm_sec=3, tm_wday=2, tm_yday=198, tm_isdst=0)

Getting formatted time

You can layout any time as in line with your requirement, but simple method to get time in readable format is asctime() −

#!/usr/bin/python
import time;

localtime = time.asctime( time.localtime(time.time()) )
print "Local current time :", localtime

This might produce the subsequent end result −

Local current time : Tue Jan 13 10:17:09 2009

Getting calendar for a month

The calendar module gives a wide range of strategies to play with yearly and monthly calendars. Here, we print a calendar for a given month ( Jan 2008 ) −

#!/usr/bin/python
import calendar

cal = calendar.month(2008, 1)
print "Here is the calendar:"
print cal

This could produce the following end result −

Here is the calendar:
   January 2008
Mo Tu We Th Fr Sa Su
    1  2  3  4  5  6
 7  8  9 10 11 12 13
14 15 16 17 18 19 20
21 22 23 24 25 26 27
28 29 30 31

Python – Date & Time, The time Module

There is a popular time module to be had in Python which offers functions for operating with instances and for changing among representations. Here is the listing of all to be had techniques −

Sr.No.	Function with Description
1	time.altzoneThe offset of the local DST timezone, in seconds west of UTC, if one is defined. This is negative if the local DST timezone is east of UTC (as in Western Europe, including the UK). Only use this if daylight is nonzero.
2	time.asctime([tupletime])Accepts a time-tuple and returns a readable 24-character string such as ‘Tue Dec 11 18:07:14 2008’.
3	time.clock( )Returns the current CPU time as a floating-point number of seconds. To measure computational costs of different approaches, the value of time.clock is more useful than that of time.time().
4	time.ctime([secs])Like asctime(localtime(secs)) and without arguments is like asctime( )
5	time.gmtime([secs])Accepts an instant expressed in seconds since the epoch and returns a time-tuple t with the UTC time. Note : t.tm_isdst is always 0
6	time.localtime([secs])Accepts an instant expressed in seconds since the epoch and returns a time-tuple t with the local time (t.tm_isdst is 0 or 1, depending on whether DST applies to instant secs by local rules).
7	time.mktime(tupletime)Accepts an instant expressed as a time-tuple in local time and returns a floating-point value with the instant expressed in seconds since the epoch.
8	time.sleep(secs)Suspends the calling thread for secs seconds.
9	time.strftime(fmt[,tupletime])Accepts an instant expressed as a time-tuple in local time and returns a string representing the instant as specified by string fmt.
10	time.strptime(str,fmt=’%a %b %d %H:%M:%S %Y’)Parses str according to format string fmt and returns the instant in time-tuple format.
11	time.time( )Returns the current time instant, a floating-point number of seconds since the epoch.
12	time.tzset()Resets the time conversion rules used by the library routines. The environment variable TZ specifies how this is done.

Let us go through the functions in short −

There are following crucial attributes available with time module −

Sr.No.	Attribute with Description
1	time.timezoneAttribute time.timezone is the offset in seconds of the local time zone (without DST) from UTC (>0 in the Americas; <=0 in most of Europe, Asia, Africa).
2	time.tznameAttribute time.tzname is a pair of locale-dependent strings, which are the names of the local time zone without and with DST, respectively.

Python – Date & Time, The calendar Module

The calendar module resources calendar-related features, consisting of functions to print a textual content calendar for a given month or yr.

Python – Date & Time, By default, calendar takes Monday because the first day of the week and Sunday as the final one. To change this, name calendar.Setfirstweekday() function.

Here is a listing of capabilities to be had with the calendar module −

Sr.No.	Function with Description
1	calendar.calendar(year,w=2,l=1,c=6)Returns a multiline string with a calendar for year year formatted into three columns separated by c spaces. w is the width in characters of each date; each line has length 21*w+18+2*c. l is the number of lines for each week.
2	calendar.firstweekday( )Returns the current setting for the weekday that starts each week. By default, when calendar is first imported, this is 0, meaning Monday.
3	calendar.isleap(year)Returns True if year is a leap year; otherwise, False.
4	calendar.leapdays(y1,y2)Returns the total number of leap days in the years within range(y1,y2).
5	calendar.month(year,month,w=2,l=1)Returns a multiline string with a calendar for month month of year year, one line per week plus two header lines. w is the width in characters of each date; each line has length 7*w+6. l is the number of lines for each week.
6	calendar.monthcalendar(year,month)Returns a list of lists of ints. Each sublist denotes a week. Days outside month month of year year are set to 0; days within the month are set to their day-of-month, 1 and up.
7	calendar.monthrange(year,month)Returns two integers. The first one is the code of the weekday for the first day of the month month in year year; the second one is the number of days in the month. Weekday codes are 0 (Monday) to 6 (Sunday); month numbers are 1 to 12.
8	calendar.prcal(year,w=2,l=1,c=6)Like print calendar.calendar(year,w,l,c).
9	calendar.prmonth(year,month,w=2,l=1)Like print calendar.month(year,month,w,l).
10	calendar.setfirstweekday(weekday)Sets the first day of each week to weekday code weekday. Weekday codes are 0 (Monday) to 6 (Sunday).
11	calendar.timegm(tupletime)The inverse of time.gmtime: accepts a time instant in time-tuple form and returns the same instant as a floating-point number of seconds since the epoch.
12	calendar.weekday(year,month,day)Returns the weekday code for the given date. Weekday codes are 0 (Monday) to 6 (Sunday); month numbers are 1 (January) to 12 (December).

Python – Date & Time, Other Modules & Functions

If you are interested, then here you will discover a listing of different critical modules and capabilities to play with date & time in Python −

• The datetime Module
• The pytz Module
• The dateutil Module