WEBVTT 00:02.190 --> 00:03.180 Hello and welcome back. 00:03.180 --> 00:05.820 So in the last session we learned about four loops. 00:05.820 --> 00:12.300 And now in this session we want to increase the functionality or the flexibility of our followers by 00:12.300 --> 00:14.830 introducing the key words continue. 00:14.850 --> 00:16.700 Break and pass. 00:16.710 --> 00:26.750 So first of all let's create a list L with the elements 1 3 5 7 10 11 13 14 and 15. 00:26.770 --> 00:30.800 What we want to do now we want to find the first even element an hour. 00:31.140 --> 00:37.110 So what does even means that even means that I am modulo 2 equals zero. 00:37.110 --> 00:40.560 We are introducing a fault of every element an error. 00:40.590 --> 00:46.190 And then we are having an if statement if I model two is zero. 00:46.200 --> 00:52.090 Then please print me the first even elements X and this element is odd. 00:52.140 --> 00:59.610 Then please print me the elements at so let's have a look what we get here. 01:00.290 --> 01:01.010 And here we get. 01:01.010 --> 01:01.370 Okay. 01:01.370 --> 01:04.350 One is up 3 Assad fighters not seven Assad. 01:04.460 --> 01:07.940 Then the first element is 10 first even element. 01:07.940 --> 01:12.770 But now you can see that iteration goes on until the very last element 15. 01:12.770 --> 01:19.550 But what we actually wanted we wanted to determine the first element that is even and we do not care 01:19.550 --> 01:24.230 about all any other elements that comes after the first even element. 01:24.470 --> 01:29.050 And therefore we can here include the keyboard break. 01:29.150 --> 01:31.200 So let's execute again. 01:31.350 --> 01:36.610 They can see that the iteration stops once we have reached the first even element. 01:36.630 --> 01:40.220 So what Python is doing here it iterate over the list. 01:40.220 --> 01:47.780 And once our condition is met once so tense our first even element we print it and then break means 01:47.810 --> 01:50.420 that we completely stop the iteration here. 01:50.420 --> 01:50.890 All right. 01:50.990 --> 01:56.120 We are only interested in the first even element we do not care about what elements so we don't want 01:56.120 --> 02:00.650 to print out that let's for example say one is up and. 02:00.810 --> 02:01.010 Yeah. 02:01.030 --> 02:08.330 What we can do B can instead of having here the action print the element is what we can just say pass 02:08.330 --> 02:09.150 or do nothing. 02:09.270 --> 02:19.030 If an element is not and they can see it the only message the only result we get is that the first element 02:19.030 --> 02:27.640 is 10 and even we we don't actually need here hear the complete s statement so if you just delete it 02:28.950 --> 02:30.010 then it also works. 02:30.450 --> 02:33.870 So now maybe you're asking yourself why do we need the pass statement. 02:33.870 --> 02:37.180 I mean here we just deleted the whole s statement. 02:37.180 --> 02:40.570 But let's assume we want to have the if statement the other way around. 02:40.560 --> 02:44.410 So first of all we want to check if the element is art. 02:44.430 --> 02:47.030 And in this case we just want to do nothing. 02:47.160 --> 02:55.740 And if it's not art we want to print the very first even element and let's run the cell here and you 02:55.740 --> 03:00.790 see it still works because here we are saying if the element is art then pass. 03:01.140 --> 03:02.190 But what if we. 03:02.280 --> 03:06.660 But what if we completely cross out paths and just have nothing here. 03:06.660 --> 03:09.150 So if the element is up I do not care. 03:09.180 --> 03:17.950 I'm not interested in again error message so far a statement we always have to define an action and 03:17.950 --> 03:23.030 if you want to do nothing the past keyword is just a fill about which we need. 03:23.140 --> 03:24.880 Otherwise we get an error message. 03:24.880 --> 03:29.490 All right so we'll have a better understanding how the path keyword works. 03:29.560 --> 03:31.590 We are just here having the same code. 03:31.600 --> 03:35.010 But after our past keyword we say OK. 03:35.040 --> 03:44.050 Even if our element is Art please print me the element and then we get one two three five seven and 03:44.050 --> 03:46.960 then the first element even element is 10. 03:47.140 --> 03:52.740 So maybe you want to print out all other elements but what if we don't want to print out all elements 03:52.760 --> 03:58.270 so we are checking if an element is up and if it's art we are just wanting to go to the next element 03:58.960 --> 04:02.140 and they are the keyword continue comes in to play. 04:02.140 --> 04:10.850 So instead of having pass here we have continue and still we have printed. 04:10.890 --> 04:14.340 But let's look if the behavior is different. 04:14.820 --> 04:18.830 And here you can see we are just having the statement the first even element is 10. 04:18.820 --> 04:20.590 So what Python does here. 04:20.610 --> 04:29.220 It checks whether an element is odd and if it's art continuum means please go to the next element do 04:29.220 --> 04:32.190 nothing and go to the next element even don't print it. 04:32.190 --> 04:35.770 So that's actually the difference between past and continue. 04:35.910 --> 04:42.180 So continuous is a keyword saying that please go to the next element and pass is just a keyword for 04:42.220 --> 04:43.500 please do nothing. 04:43.500 --> 04:45.050 And to make it a little bit more clear. 04:45.060 --> 04:49.010 So let's assume we still want to find the first even element. 04:49.050 --> 04:51.380 But for whatever reason we want to exclude 10. 04:51.390 --> 04:53.010 As a result that's the here. 04:53.010 --> 04:54.840 So this is the code we already know. 04:54.840 --> 05:03.360 So if two is even then please print the first even elements x y z and then please break the if you want 05:03.360 --> 05:05.140 to exclude that we get 10. 05:05.190 --> 05:10.830 We have to introduce another if statement saying if I equals 10 please continue. 05:10.830 --> 05:15.780 So please ignore if 10 this and minus because I don't want to have 10 as a result 05:18.980 --> 05:22.010 so this gets me here 14 as a final result. 05:22.020 --> 05:26.460 So the first even element is 14 because I just ignore 10. 05:26.480 --> 05:28.660 All right so this is it for the time being. 05:28.660 --> 05:31.010 And I hope to you in the next session by.