Monday, July 13, 2020

Python Date and Time with examples



Hello guys! Welcome back to another section of my tutorial on Python. In this tutorial guide, we are going to be studying about the Python Date and Time.

A Python program can handle date and time in several ways. Converting between date formats is a common chore for computers. The Python's time and calendar module help track dates and time.

What is Tick?

Time intervals are floating - point numbers which are in the units of seconds. A particular instant in time are being expressed in seconds since 12:00am, January 1, 1970.

There is a popular time module that is available in Python which provides functions for working with times and also for converting between several representations. The Python module time.time() returns the current time in ticks since 12:00am, January 1, 1970.


Example

Following below is a simple 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

Output

Below is the output of the above example -

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

Date arithmetic is easy to do with ticks. But the dates before the epoch can not be represented in this form. Dates in the far future also can not be represented in this form. The cut off point is sometime in 2038 for UNIX and Windows.

What is Time Tuple?

Many of the Python's time function handle time as a tuple of 9 numbers, as shown below -

IndexFieldValues
04-digit year2008
1Month1 to 12
2Day1 to 31
3Hour0 to 23
4Minute0 to 59
5Second0 to 61 (60 or 61 are leap-seconds)
6Day of Week0 to 6 (0 is Monday)
7Day of year1 to 366 (Julian day)
8Daylight savings-1, 0, 1, -1 means library determines DST

RECOMMENDED POST: Decision Making in Python

The above tuple is equivalent to the struct_time structure. The structure has following attributes -

IndexAttributesValues
0tm_year2008
1tm_mon1 to 12
2tm_mday1 to 31
3tm_hour0 to 23
4tm_min0 to 59
5tm_sec0 to 61 (60 or 61 are leap-seconds)
6tm_wday0 to 6 (0 is Monday)
7tm_yday1 to 366 (Julian day)
8tm_isdst-1, 0, 1, -1 means library determines DST

Getting Current Time

To translate a time instant from a second since the epoch floating-point value into a time-tuple, then pass the floating-point value to the function (e.g., localtime) that returns a time-tuple with all nine items valid.

Example

Following below is a simple example -

#!/usr/bin/python
import time;

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

Output

This would produce the following result, which could be formatted in any other orderly form -

Local current time : time.struct_time(tm_year=2020, tm_mon=7, 
tm_mday=13, tm_hour=15, tm_min=26, tm_sec=35, tm_wday=0, tm_yday=198, tm_isdst=0)

RECOMMENDED POST: Python Operators

Getting Formatted Time

You can format any time based on your needs, but the simple method of getting time in a readable format is asctime -

Example

Following below is a simple example -

#!/usr/bin/python
import time;

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

Output

Below is the output of the above example -

Local current time : Mon Jul 13 15:45:38 2020

Getting Calendar for a Month

The Python calendar module gives a wide range of methods to play with the yearly and monthly calendars. Here, we print a calendar for a given month ( Jul 2020 ) -

#!/usr/bin/python
import calendar

cal = calendar.month(2020, 07)
print "Here is the calendar:"
print cal

Output

Below is the output of the above example -

Here is the calendar:
   July 2020
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

RECOMMENDED POST: Python Basic Syntax Tutorial


The Time Module
There is a popular time module that is available in Python which provides functions for working with times and also used for converting between the representations. Here is a list of all the available methods -

Sr.No.Function with Description
1time.altzone
The 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.
2time.asctime([tupletime])
Accepts a time-tuple and returns a readable 24-character string such as 'Tue Dec 11 18:07:14 2008'.
3time.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().
4time.ctime([secs])
Like asctime(localtime(secs)) and without arguments is like asctime( )
5time.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
6time.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).
7time.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.
8time.sleep(secs)
Suspends the calling thread for secs seconds.
9time.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.
10time.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.
11time.time( )
Returns the current time instant, a floating-point number of seconds since the epoch.
12time.tzset()
Resets the time conversion rules used by the library routines. The environment variable TZ specifies how this is done.

In our subsequent tutorials, we are going to be discussing about each of the above methods.

Following below are two important attributes available with time module -

Sr.No.Attribute with Description
1
time.timezone
Attribute 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.tzname
Attribute time.tzname is a pair of locale-dependent strings, which are the names of the local time zone without and with DST, respectively.



The Calendar Module
Python's calendar module supplies calendar related functions, including functions for printing a text calendar for a given month or year.

By default, calendar takes Monday as the first day of the week and Sunday as the last. In order to change this, then call calendar.setfirstweekday() function.

Following below is the list of the modules available 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).

RECOMMENDED POST: Python Variables and Data Types 

Alright guys! This is where we are rounding up for this tutorial post. In my next tutorial, we are going to be discussing about the Python Time altzone() Method

Feel free to ask your questions where necessary and i will attend to them as soon as possible. If this tutorial was helpful to you, you can use the share button to share this tutorial.

Follow us on our various social media platforms to stay updated with our latest tutorials. You can also subscribe to our newsletter in order to get our tutorials delivered directly to your emails.

Thanks for reading and bye for now.
Share:

0 comments:

Post a Comment

Hello dear readers! Please kindly try your best to make sure your comments comply with our comment policy guidelines. You can visit our comment policy page to view these guidelines which are clearly stated. Thank you.