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`timedelta` is a really handy tool. Let's see more about how to use them.

`timedelta`

objects represent gaps in time. They are returned when you subtract one `datetime`

from another. They can also be assigned to a variable and then used to augment `datetime`

objects.

Like we saw in the last video, timedelta objects represent a gap of time. 0:00 We can get them by subtracting one datetime object from another, but 0:04 we can actually create them on their own. 0:08 Let's check them out on their own with datetimes, with dates, and with times. 0:10 So since I've reset my Python interpreter, I need to import datetime again. 0:15 And let's make an object that represents now, just so 0:21 we don't have to keep typing out datetime.datetime.now. 0:24 And we don't really care if we have new values or not. 0:28 We just want something that's held on to here. 0:31 Let's see if we can move this forward in time by three days. 0:34 So, the way that we manipulate date times is with our timedeltas. 0:38 So, let's make a timedelta and we can say in here like, hours equals 5. 0:43 Okay, and I've got this thing back and you see it's 18,000 seconds. 0:49 What I wanna do though is I want to make one of these that's days. 0:54 So, I wanna do days equals we said 3, so 3. 0:59 So we just got a three there. 1:07 You notice we had the zero before. 1:08 That's because it was zero days it was just five hours. 1:10 Okay if I was to do now plus daytime.time delta days equals 3. 1:13 Then where it was the 15th, it is now the 18th, okay? 1:19 . 1:26 Everything else is exactly the same, right? 1:26 It's still 18 hours and 30 seconds or sorry, 18 hours and 30 minutes. 1:29 Just the days changed. 1:34 All right, what if I wanted to go back in time? 1:35 So we could do now plus datetime.timedelta, 1:38 days equals, lets go back five days. 1:44 I did minus five days. 1:47 So again, we went from the 15th to the 10th. 1:49 Now, adding negative five days, that's a little confusing to some people. 1:52 I can see why, it's a little strange. 1:57 So what we can do is we can actually subtract. 1:59 So, let's do now minus datetime.timedelta days equal 5. 2:01 So we've subtracted five days, we get the exact same number. 2:07 So it works. 2:11 It gives us the same day. 2:12 So we have two different ways to manipulate our datetimes. 2:13 So what if we just want a date? 2:17 Or we just want a time? 2:20 I just want the date. 2:22 I don't care about what time it is. 2:23 So I can actually do now.date, and I get back a date. 2:24 And I can do now.time and I get back a time. 2:29 So these can be used if I just need the time, I just need the, the date, whatever. 2:33 What else can we do with these, though? 2:38 Well, we can work with multiple timedeltas, which is kinda cool. 2:40 So let's make a timedelta here that's hour, which is a timedelta hours equals 1. 2:44 So it's one hour long. 2:51 3600 minute seconds. 2:52 And we're gonna say a workday equals hour times 9. 2:55 Cuz you got a lunch hour. 2:59 So eight hour day plus one hour lunch gives you nine hours, right? 3:01 Let's do tomorrow equals datetime.datetime.now.replace 3:05 hour equals 9, minute equals 0. 3:12 And then really, we should do plus datetime.timedelta days equal 1. 3:16 So if we look at tomorrow, that's tomorrow morning at 9 a.m, more or 3:26 less we've got a couple seconds in there, but whatever. 3:30 If we did that and 3:32 we want to say okay what time would I be off tomorrow, if it wasn't standard. 3:33 We could do tomorrow plus work day and we get out 18:00. 3:38 So six, 6 p.m. 3:43 That's really nice. 3:44 I, I can use this to calculate the ends of an appointment or something. 3:46 I just need to make a timedelta as the length of the appointment. 3:49 So let's see. 3:52 We did appointment equals datetime.timedelta minutes equals 45. 3:53 Maybe I have a standard 45 minute meeting slot that I give out. 3:59 All right and we'll say the start is a datetime of the 1st of November and 4:03 it's gonna be 45 minutes after noon. 4:12 Okay? 4:17 So, the end of that is going to be start plus appointment. 4:18 And if we look at end, 4:23 then we see that it ends at 1:30 which is 45 minutes after 12:45. 4:24 >> Manipulating datetimes with timedelta is probably the best part of the datetime 4:30 library. 4:34 It's fairly simple and intuitive and it's really handy for 4:35 a lot of real world scenarios. 4:37

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