U ovom ćete članku naučiti manipulirati datumom i vremenom u Pythonu uz pomoć primjera.
Python ima modul nazvan datetime za rad s datumima i vremenima. Stvorimo nekoliko jednostavnih programa povezanih s datumom i vremenom prije nego što dublje zakopamo.
Primjer 1: Dohvatite trenutni datum i vrijeme
import datetime datetime_object = datetime.datetime.now() print(datetime_object)
Kada pokrenete program, izlaz će biti otprilike:
2018-12-19 09: 26: 03.478039
Ovdje smo uveli modul datuma i vremena koristeći import datetimenaredbu.
Jedna od klasa definiranih u datetimemodulu je datetimeklasa. Zatim smo now()metodom stvorili datetimeobjekt koji sadrži trenutni lokalni datum i vrijeme.
Primjer 2: Dohvatite trenutni datum
import datetime date_object = datetime.date.today() print(date_object)
Kada pokrenete program, izlaz će biti otprilike:
2018-12-19
U ovom smo programu koristili today()metodu definiranu u dateklasi da bismo dobili dateobjekt koji sadrži trenutni lokalni datum.
Što je unutra datum i vrijeme?
Možemo koristiti funkciju dir () da bismo dobili popis koji sadrži sve atribute modula.
import datetime print(dir(datetime))
Kada pokrenete program, izlaz će biti:
('MAXYEAR', 'MINYEAR', '__builtins__', '__cached__', '__doc__', '__file__', '__loader__', '__name__', '__package__', '__spec__', '_divide_and_round', 'date', ' datetime ',' datetime_CAPI ',' time ',' timedelta ',' timezone ',' tzinfo ')
Uobičajene klase u modulu datetime su:
- datum Razred
- vrijeme Klasa
- datum i vrijeme Razred
- klasa timedelta
datetime.date Klasa
Možete instancirati dateobjekte iz dateklase. Objekt datuma predstavlja datum (godinu, mjesec i dan).
Primjer 3: Datumski objekt koji predstavlja datum
import datetime d = datetime.date(2019, 4, 13) print(d)
Kada pokrenete program, izlaz će biti:
2019-04-13
Ako se pitate, date()u gornjem primjeru je konstruktor dateklase. Konstruktor uzima tri argumenta: godinu, mjesec i dan.
Varijabla a je dateobjekt.
dateKlasu možemo uvesti samo iz datetimemodula. Evo kako:
from datetime import date a = date(2019, 4, 13) print(a)
Primjer 4: Dohvatite trenutni datum
dateObjekt koji sadrži trenutni datum možete stvoriti pomoću imenovane metode klase today(). Evo kako:
from datetime import date today = date.today() print("Current date =", today)
Primjer 5: Dohvatite datum iz vremenske oznake
dateObjekte možemo stvoriti i iz vremenske oznake. Unix vremenska oznaka je broj sekundi između određenog datuma i 1. siječnja 1970. u UTC. Oznaku vremena možete pretvoriti u datum pomoću fromtimestamp()metode.
from datetime import date timestamp = date.fromtimestamp(1326244364) print("Date =", timestamp)
Kada pokrenete program, izlaz će biti:
Datum = 2011-11-11
Primjer 6: Ispišite današnju godinu, mjesec i dan
Iz objekta datuma možemo lako dobiti godinu, mjesec, dan, dan u tjednu itd. Itd. Evo kako:
from datetime import date # date object of today's date today = date.today() print("Current year:", today.year) print("Current month:", today.month) print("Current day:", today.day)
datetime.time
Vremenski objekt instanciran iz timeklase predstavlja lokalno vrijeme.
Primjer 7: Objekt vremena koji predstavlja vrijeme
from datetime import time # time(hour = 0, minute = 0, second = 0) a = time() print("a =", a) # time(hour, minute and second) b = time(11, 34, 56) print("b =", b) # time(hour, minute and second) c = time(hour = 11, minute = 34, second = 56) print("c =", c) # time(hour, minute, second, microsecond) d = time(11, 34, 56, 234566) print("d =", d)
Kada pokrenete program, izlaz će biti:
a = 00:00:00 b = 11:34:56 c = 11:34:56 d = 11: 34: 56,234566
Primjer 8: Ispis sata, minute, sekunde i mikrosekunde
Jednom kada stvorite timeobjekt, lako možete ispisati njegove atribute kao što su sat, minuta itd.
from datetime import time a = time(11, 34, 56) print("hour =", a.hour) print("minute =", a.minute) print("second =", a.second) print("microsecond =", a.microsecond)
Kada pokrenete primjer, izlaz će biti:
sat = 11 minuta = 34 sekunde = 56 mikrosekundi = 0
Primijetite da nismo proslijedili mikrosekundni argument. Stoga 0se ispisuje njegova zadana vrijednost .
datetime.datetime
The datetime module has a class named dateclass that can contain information from both date and time objects.
Example 9: Python datetime object
from datetime import datetime #datetime(year, month, day) a = datetime(2018, 11, 28) print(a) # datetime(year, month, day, hour, minute, second, microsecond) b = datetime(2017, 11, 28, 23, 55, 59, 342380) print(b)
When you run the program, the output will be:
2018-11-28 00:00:00 2017-11-28 23:55:59.342380
The first three arguments year, month and day in the datetime() constructor are mandatory.
Example 10: Print year, month, hour, minute and timestamp
from datetime import datetime a = datetime(2017, 11, 28, 23, 55, 59, 342380) print("year =", a.year) print("month =", a.month) print("hour =", a.hour) print("minute =", a.minute) print("timestamp =", a.timestamp())
When you run the program, the output will be:
year = 2017 month = 11 day = 28 hour = 23 minute = 55 timestamp = 1511913359.34238
datetime.timedelta
A timedelta object represents the difference between two dates or times.
Example 11: Difference between two dates and times
from datetime import datetime, date t1 = date(year = 2018, month = 7, day = 12) t2 = date(year = 2017, month = 12, day = 23) t3 = t1 - t2 print("t3 =", t3) t4 = datetime(year = 2018, month = 7, day = 12, hour = 7, minute = 9, second = 33) t5 = datetime(year = 2019, month = 6, day = 10, hour = 5, minute = 55, second = 13) t6 = t4 - t5 print("t6 =", t6) print("type of t3 =", type(t3)) print("type of t6 =", type(t6))
When you run the program, the output will be:
t3 = 201 days, 0:00:00 t6 = -333 days, 1:14:20 type of t3 = type of t6 =
Notice, both t3 and t6 are of type.
Example 12: Difference between two timedelta objects
from datetime import timedelta t1 = timedelta(weeks = 2, days = 5, hours = 1, seconds = 33) t2 = timedelta(days = 4, hours = 11, minutes = 4, seconds = 54) t3 = t1 - t2 print("t3 =", t3)
When you run the program, the output will be:
t3 = 14 days, 13:55:39
Here, we have created two timedelta objects t1 and t2, and their difference is printed on the screen.
Example 13: Printing negative timedelta object
from datetime import timedelta t1 = timedelta(seconds = 33) t2 = timedelta(seconds = 54) t3 = t1 - t2 print("t3 =", t3) print("t3 =", abs(t3))
When you run the program, the output will be:
t3 = -1 day, 23:59:39 t3 = 0:00:21
Example 14: Time duration in seconds
You can get the total number of seconds in a timedelta object using total_seconds() method.
from datetime import timedelta t = timedelta(days = 5, hours = 1, seconds = 33, microseconds = 233423) print("total seconds =", t.total_seconds())
When you run the program, the output will be:
total seconds = 435633.233423
You can also find sum of two dates and times using + operator. Also, you can multiply and divide a timedelta object by integers and floats.
Python format datetime
The way date and time is represented may be different in different places, organizations etc. It's more common to use mm/dd/yyyy in the US, whereas dd/mm/yyyy is more common in the UK.
Python has strftime() and strptime() methods to handle this.
Python strftime() - datetime object to string
The strftime() method is defined under classes date, datetime and time. The method creates a formatted string from a given date, datetime or time object.
Example 15: Format date using strftime()
from datetime import datetime # current date and time now = datetime.now() t = now.strftime("%H:%M:%S") print("time:", t) s1 = now.strftime("%m/%d/%Y, %H:%M:%S") # mm/dd/YY H:M:S format print("s1:", s1) s2 = now.strftime("%d/%m/%Y, %H:%M:%S") # dd/mm/YY H:M:S format print("s2:", s2)
When you run the program, the output will be something like:
time: 04:34:52 s1: 12/26/2018, 04:34:52 s2: 26/12/2018, 04:34:52
Here, %Y, %m, %d, %H etc. are format codes. The strftime() method takes one or more format codes and returns a formatted string based on it.
In the above program, t, s1 and s2 are strings.
%Y- year (0001,… , 2018, 2019,… , 9999)%m- month (01, 02,… , 11, 12)%d- day (01, 02,… , 30, 31)%H- hour (00, 01,… , 22, 23%M- minute (00, 01,… , 58, 59)%S- second (00, 01,… , 58, 59)
To learn more about strftime() and format codes, visit: Python strftime().
Python strptime() - string to datetime
The strptime() method creates a datetime object from a given string (representing date and time).
Example 16: strptime()
from datetime import datetime date_string = "21 June, 2018" print("date_string =", date_string) date_object = datetime.strptime(date_string, "%d %B, %Y") print("date_object =", date_object)
When you run the program, the output will be:
date_string = 21 June, 2018 date_object = 2018-06-21 00:00:00
The strptime() method takes two arguments:
- niz koji predstavlja datum i vrijeme
- kod formata ekvivalentan prvom argumentu
Usput, %d, %Bi %Yformat kodovi se koriste za dan, mjesec (puni naziv) i godišnje respektivno.
Posjetite Python strptime () da biste saznali više.
Rukovanje vremenskom zonom u Pythonu
Pretpostavimo da radite na projektu i trebate prikazati datum i vrijeme na temelju njihove vremenske zone. Umjesto da sami pokušavate obraditi vremensku zonu, predlažemo da koristite nezavisni pytZ modul.
from datetime import datetime import pytz local = datetime.now() print("Local:", local.strftime("%m/%d/%Y, %H:%M:%S")) tz_NY = pytz.timezone('America/New_York') datetime_NY = datetime.now(tz_NY) print("NY:", datetime_NY.strftime("%m/%d/%Y, %H:%M:%S")) tz_London = pytz.timezone('Europe/London') datetime_London = datetime.now(tz_London) print("London:", datetime_London.strftime("%m/%d/%Y, %H:%M:%S"))
Kada pokrenete program, izlaz će biti otprilike:
Lokalno vrijeme: 2018-12-20 13: 10: 44.260462 Amerika / New_York vrijeme: 2018-12-20 13: 10: 44.260462 Europa / London vrijeme: 2018-12-20 13: 10: 44.260462
Ovdje su datetime_NY i datetime_London objekti datetime koji sadrže trenutni datum i vrijeme njihove odgovarajuće vremenske zone.
