WEBVTT 00:00.140 --> 00:00.830 Hello guys. 00:00.830 --> 00:03.050 We are going to continue the discussion with respect to Python. 00:03.050 --> 00:05.600 And in this video we are going to talk about loops. 00:05.600 --> 00:10.430 Already in our previous video we have uh, we have seen a lot of examples with respect to conditional 00:10.430 --> 00:13.040 statements like if else, if else. 00:13.040 --> 00:19.130 And we have seen multiple examples out there right now in loops, we will be discussing about what are 00:19.130 --> 00:24.860 the different types of loop we usually use in Python programming language, like for loop while loop 00:25.100 --> 00:27.680 loop control statements like break, continue and pass. 00:27.680 --> 00:32.180 Then we'll be discussing about nested loops, and then we'll be seeing like all these things, we will 00:32.210 --> 00:35.660 be seeing much more in with the help of practical examples. 00:35.810 --> 00:39.920 And what are the common errors we usually face and how to avoid those errors. 00:39.920 --> 00:42.320 So all these things we'll be discussing in this particular video. 00:42.320 --> 00:48.620 So first of all let's go ahead and work with for loop with a simple, uh, you know, syntax. 00:48.620 --> 00:53.780 So in order to write a for loop right you need to understand what a for loop is. 00:53.810 --> 00:55.640 A for loop is a loop right. 00:55.640 --> 00:58.220 It is used to iterate over a sequence of numbers. 00:58.250 --> 00:58.790 Okay. 00:58.790 --> 01:01.980 So let's say I will give one example like for AI. 01:02.010 --> 01:07.800 Okay, AI is just a temporary variable right now in let's say I want to create a sequence of numbers. 01:07.800 --> 01:12.270 Now, in order to create a sequence of numbers, I will show you with the help of range. 01:12.300 --> 01:12.480 Okay. 01:12.510 --> 01:14.580 So what exactly is range okay. 01:14.610 --> 01:18.270 So let's say in this particular range I give five elements. 01:18.270 --> 01:20.040 I basically want five elements over here. 01:20.040 --> 01:24.360 So this is turn actually help us to generate numbers between 0 to 5. 01:24.390 --> 01:24.720 Right. 01:24.720 --> 01:30.030 So here you can see that hey I'm getting a range between 0 to 5 over here. 01:30.030 --> 01:36.390 And let's say I want to just display all these numbers inside this right range is just giving us a sequence 01:36.390 --> 01:37.800 of numbers between 0 to 5. 01:37.830 --> 01:42.360 But if I want to iterate through this, all the numbers I can basically use for loop. 01:42.360 --> 01:46.560 So if I write for I in range five, right. 01:46.560 --> 01:52.950 And here if I go ahead and print I right now, you will be seeing that after every iteration. 01:52.950 --> 01:58.320 First of all, when we are looping inside this sequence of numbers between 0 to 5, first it will go 01:58.350 --> 01:59.790 ahead and display zero. 01:59.820 --> 02:01.900 Then it will go ahead and display one. 02:01.930 --> 02:06.460 That basically means after every iteration, this number is basically getting incremented and it is 02:06.460 --> 02:08.620 traversing through all this range of numbers. 02:08.650 --> 02:14.170 One important thing that you should understand that since I have used range between 0 to 5, the last 02:14.170 --> 02:15.700 number is not going to get included. 02:15.700 --> 02:20.290 So that is the reason you can see zero is here, one is here, two is here, three is here, and four 02:20.320 --> 02:20.800 is here. 02:20.830 --> 02:21.160 Right. 02:21.190 --> 02:24.760 But the total number of elements is five over here and here. 02:24.910 --> 02:28.570 In short I have spoken about for loop and range as a function. 02:28.600 --> 02:28.810 Okay. 02:28.840 --> 02:30.850 So range as a function is also given. 02:30.850 --> 02:34.690 Let's say I want to probably use for loop with different range of numbers. 02:34.690 --> 02:34.930 Right. 02:34.930 --> 02:40.260 Let's say if I go ahead and write one comma six, that basically means I want the number between 1 to 02:40.260 --> 02:40.510 6. 02:40.510 --> 02:42.010 Six is the last number. 02:42.010 --> 02:47.800 So we are not going to include it because at the end of the day, with respect to Python, whenever 02:47.800 --> 02:50.800 we are seeing indexing right, it always starts with zero, right. 02:50.800 --> 02:53.320 So I'll talk more about it as I go ahead. 02:53.350 --> 02:57.400 Now if I go ahead and execute this here you'll be able to see one is getting displayed, two is getting 02:57.400 --> 02:59.530 displayed, three is getting displayed, four is getting displayed. 02:59.530 --> 03:00.640 Five is getting displayed. 03:00.640 --> 03:08.020 So I can also call all my range of numbers with respect to by giving numbers between one number to the 03:08.020 --> 03:09.460 other number itself, right. 03:09.730 --> 03:13.870 Now let me just give you more examples over here by using range. 03:13.870 --> 03:16.180 So if I go ahead and write range. 03:16.480 --> 03:19.360 Range of one comma ten. 03:19.360 --> 03:23.050 And let me just go ahead and give some third parameter. 03:23.080 --> 03:23.320 Right. 03:23.320 --> 03:27.760 So third parameter over here you'll be able to see that it is something called as step. 03:27.760 --> 03:29.170 Now see see the syntax. 03:29.170 --> 03:32.800 It shows start as the first parameter inside range function. 03:32.800 --> 03:34.510 Then you have the stop parameter. 03:34.510 --> 03:36.490 Then you have the step parameter okay. 03:36.520 --> 03:39.580 By default step parameter is usually given as one. 03:39.610 --> 03:43.870 Now start I'm saying hey start from one end till ten right. 03:43.900 --> 03:49.270 And before ten I will not say till ten, but before ten and use the step size as one. 03:49.270 --> 03:51.790 That basically means only increment one number at a time. 03:51.790 --> 03:56.200 So if I go ahead and execute it, this will basically give me a range of value between 1 to 10. 03:56.200 --> 03:57.970 But and the step size will be one. 03:58.000 --> 04:00.370 Right now let me just go ahead and make it two okay. 04:00.400 --> 04:03.980 So here you can see that I'm starting from one before ten. 04:04.010 --> 04:04.640 It will stop. 04:04.640 --> 04:05.930 And here the range is two. 04:05.960 --> 04:08.690 That basically means the two numbers will get incremented. 04:08.720 --> 04:09.980 Now let me do one thing. 04:10.010 --> 04:10.280 Okay. 04:10.310 --> 04:16.040 Let me just write one over here and let me use a for loop again for I in range of this. 04:16.040 --> 04:18.080 And let me go ahead and print I. 04:18.110 --> 04:18.770 Okay. 04:18.800 --> 04:22.190 Now when I'm printing I you'll be able to see that what I'm actually getting. 04:22.190 --> 04:24.140 123456789. 04:24.170 --> 04:27.350 Now let me make this change from step size 1 to 2. 04:27.380 --> 04:28.160 Now what will happen? 04:28.190 --> 04:33.320 See, after one directly three will get displayed because we are going to skip one number. 04:33.320 --> 04:35.840 So it is just going to jump two steps ahead. 04:35.840 --> 04:36.290 Right. 04:36.320 --> 04:37.400 Now see this. 04:37.640 --> 04:41.330 So now I can see 13579 right. 04:41.330 --> 04:46.400 So I am not probably traversing to each and every number, but instead I have given a step size of two. 04:46.430 --> 04:48.470 So it is jumping two numbers ahead. 04:48.890 --> 04:50.930 And that is how it is basically getting printed. 04:50.960 --> 04:52.730 Let me just show you one more example. 04:52.730 --> 04:59.450 Let's say that I want all the numbers between, um, 10 to 1. 04:59.450 --> 05:03.410 But now this time I will use a step size of minus one. 05:03.410 --> 05:08.630 Now what it is going to do, it is going to display a number between 10 to 1, and step size will be 05:08.630 --> 05:09.050 minus one. 05:09.050 --> 05:12.170 That basically means after ten it will become nine, then eight, then seven. 05:12.200 --> 05:12.800 See this. 05:12.800 --> 05:20.120 So here you can see 910 987654321 is not getting displayed as we know that last number will be skipped. 05:20.120 --> 05:22.100 Before this all the numbers will be displayed. 05:22.100 --> 05:25.010 One more example that we if I really want to show it to you. 05:25.010 --> 05:27.860 So here you can see minus two if I'm using minus two. 05:27.890 --> 05:31.310 So ten 86542642. 05:31.340 --> 05:31.790 Right. 05:31.790 --> 05:34.940 So I hope you have got an idea with respect to for loops. 05:34.940 --> 05:37.730 And with the help of range how we can actually move. 05:37.760 --> 05:38.270 Okay. 05:38.300 --> 05:42.650 Now let me show you with respect to strings I hope everybody has learned strings. 05:42.650 --> 05:43.010 Right. 05:43.010 --> 05:45.770 So strings are how to properly create string. 05:45.770 --> 05:48.110 Let's say that this is my string okay. 05:48.140 --> 05:49.310 This is my string. 05:49.340 --> 05:51.890 And here I am going to write Krish Nayak. 05:51.920 --> 05:52.490 Okay. 05:52.730 --> 05:55.430 Now if I want to traverse to this particular string. 05:55.460 --> 06:00.410 Now see, one amazing thing about this data structure called a string is that we can traverse to each 06:00.410 --> 06:01.710 and every character over here. 06:01.710 --> 06:09.030 So if I go ahead and write for I in str, okay, and uh, for I in str. 06:09.030 --> 06:12.060 And if I just go ahead and print I okay. 06:12.060 --> 06:14.550 So string is basically a data structure. 06:14.550 --> 06:15.360 It is just nothing. 06:15.360 --> 06:17.160 But it is a collection of characters. 06:17.160 --> 06:20.910 Right now if I'm going to print over here, here you can see k r I s h. 06:20.940 --> 06:22.950 Then again space and I k right. 06:22.980 --> 06:27.060 Let's say that I am traversing to this particular string. 06:27.060 --> 06:32.160 And I also want to do something like I may have a sentence, I may have a paragraph. 06:32.160 --> 06:34.590 So based on that also I can print it over here. 06:34.620 --> 06:34.890 Right. 06:34.920 --> 06:40.680 Just to give you an idea what exactly this is, uh, because string is a collection of characters, 06:40.680 --> 06:40.980 right? 06:41.010 --> 06:42.300 It is a collection of characters. 06:42.300 --> 06:43.800 And we can also traverse thing. 06:43.800 --> 06:49.260 So the for loop main functionality is that whenever you have any collection items, like any collection 06:49.260 --> 06:54.180 data structure, you can traverse through it very much easily by just using a for loop. 06:54.210 --> 06:54.630 Right. 06:54.630 --> 06:56.670 So I have just given you an idea about it. 06:56.670 --> 07:01.200 But as we go ahead, we'll be seeing more complicated example, uh, as we go ahead. 07:01.240 --> 07:01.600 Right. 07:01.600 --> 07:05.740 But just to understand the basic example, this is what a for loop is all about. 07:05.770 --> 07:09.310 Now let's go ahead and discuss about something called as while loop okay. 07:09.340 --> 07:11.770 So while loop. 07:11.950 --> 07:15.580 So now let's see something about while. 07:16.180 --> 07:18.220 So now I have a while loop. 07:18.250 --> 07:18.700 Okay. 07:18.730 --> 07:20.950 Now with respect to while loop right. 07:20.950 --> 07:28.900 If I really want to give a small definition, this while loop is nothing, but it continues to execute 07:28.900 --> 07:31.000 as long as the condition is true. 07:31.030 --> 07:31.540 Okay. 07:31.570 --> 07:36.670 That basically means unless and until this while loop, whatever condition I'm writing in while loop, 07:36.850 --> 07:38.980 it is true it is just going to execute it. 07:39.010 --> 07:39.400 Okay. 07:39.430 --> 07:40.570 Now let me do one thing. 07:40.570 --> 07:43.570 Let me create a temporary variable called as count. 07:43.600 --> 07:44.170 Okay. 07:44.710 --> 07:45.310 Count. 07:45.340 --> 07:45.730 Okay. 07:45.760 --> 07:52.150 Now with respect to this particular count, let me just go ahead and write while count is less than 07:52.150 --> 07:52.780 five. 07:54.160 --> 07:54.760 Okay. 07:54.760 --> 07:59.080 And now I have gone inside my while loop while block or while loop over here. 07:59.590 --> 08:05.530 So I'm putting this particular condition, unless until this count is not, is less than five. 08:05.560 --> 08:07.510 Just go ahead and print it. 08:07.540 --> 08:08.050 Okay. 08:08.080 --> 08:10.450 Let's say I'm going to print the count. 08:10.480 --> 08:10.990 Okay. 08:11.020 --> 08:17.080 And after this, if I'm executing C, I also need to increment the count over here. 08:17.080 --> 08:19.480 So I will go ahead and write count plus one. 08:19.570 --> 08:20.110 Okay. 08:20.140 --> 08:24.130 So what I'm doing unless and until this count is less than five I'm going to print the count. 08:24.130 --> 08:28.780 And for every iteration, because we have initially initialized, count is equal to zero. 08:28.810 --> 08:31.900 For every iteration I am writing, count is equal to count plus one. 08:31.930 --> 08:32.350 Okay. 08:32.380 --> 08:34.600 Now see what will happen if I execute this. 08:34.630 --> 08:36.490 You'll be seeing that zero is getting displayed. 08:36.490 --> 08:38.020 Initially I will be having zero. 08:38.020 --> 08:40.510 So when I write while count is less than five, this is true. 08:40.540 --> 08:42.340 It is just going to print the count. 08:42.340 --> 08:43.930 So I'm going to get zero over here. 08:43.930 --> 08:46.300 And then it is going to increment the count. 08:46.330 --> 08:49.300 Now my temporary variable count will have one value right. 08:49.330 --> 08:55.000 I'll not say temporary, but my count value from this zero has got incremented to one. 08:55.030 --> 08:57.160 Then again this file while loop will run. 08:57.160 --> 08:57.340 Why? 08:57.340 --> 09:00.430 It will run because this condition is still true, right? 09:00.430 --> 09:03.140 So now here you can see when one is less than five. 09:03.140 --> 09:04.430 So one is obviously less than five. 09:04.460 --> 09:05.240 In the second loop. 09:05.240 --> 09:06.800 So again this will get executed. 09:06.800 --> 09:08.330 Then again this will get incremented. 09:08.330 --> 09:09.770 Then again it will go to the next loop. 09:09.770 --> 09:11.870 Then this will become 234. 09:11.900 --> 09:12.440 Then. 09:12.440 --> 09:15.050 But once it becomes five right. 09:15.080 --> 09:17.750 While five is less than five now this becomes false. 09:17.750 --> 09:19.970 It is just going to come outside the loop, right. 09:19.970 --> 09:24.080 So that is how you are getting displayed with 01234. 09:24.110 --> 09:24.500 Right. 09:24.500 --> 09:30.020 So this is a simple way of probably displaying or understanding about the while loop. 09:30.050 --> 09:30.560 Okay. 09:30.860 --> 09:34.730 Uh, I may also write something like this while okay. 09:34.760 --> 09:36.080 Let's go ahead and write. 09:36.110 --> 09:38.750 Count is equal to zero okay. 09:40.700 --> 09:52.520 Count is equal to zero while count while count percentile two is double equal to zero okay. 09:52.550 --> 09:54.020 So now see this condition. 09:54.020 --> 09:59.210 What I'm saying while count percentile two is double equal to zero. 09:59.210 --> 10:04.200 If this is true right I will probably go ahead and print the count over here. 10:04.620 --> 10:05.130 Right? 10:05.460 --> 10:05.880 Right. 10:05.880 --> 10:11.160 And let's say that I will go ahead and or let me do one thing. 10:11.190 --> 10:11.490 Okay. 10:11.520 --> 10:13.590 If I'm starting from count is equal to zero. 10:13.620 --> 10:17.130 And this condition is basically to check whether a number is even number or not. 10:17.160 --> 10:17.580 Right. 10:17.610 --> 10:21.690 So if I just go ahead and execute it, how many times this will get displayed. 10:21.720 --> 10:23.880 See zero is getting displayed over here right. 10:23.880 --> 10:25.440 And it is continuously getting displayed. 10:25.440 --> 10:26.220 I'll stop this. 10:26.250 --> 10:28.350 See because I have not written any condition over here. 10:28.350 --> 10:29.910 So let me just go ahead and write. 10:29.940 --> 10:32.730 Count is equal to count plus one okay. 10:32.790 --> 10:34.860 Now how many times it will get displayed. 10:34.860 --> 10:36.060 You just see this okay. 10:36.090 --> 10:37.050 Only one time. 10:37.050 --> 10:39.660 Because the next time it became one this count became one. 10:39.690 --> 10:41.460 Then one percentile two is not equal to zero. 10:41.460 --> 10:45.840 So it is just going to come outside of the loop right of this particular loop. 10:45.840 --> 10:48.030 This is just to show you an example over here. 10:48.030 --> 10:50.940 But we will be seeing with more amazing examples. 10:50.940 --> 10:55.290 First of all, let's go ahead and just see the basic syntax of for while. 10:55.290 --> 11:00.060 And now we are going to go ahead with respect to loop control statements okay. 11:00.060 --> 11:02.790 Loop control statements. 11:03.720 --> 11:05.070 You'll be seeing that crash. 11:05.100 --> 11:05.580 Uh. 11:05.760 --> 11:06.960 Uh, please give more examples. 11:06.990 --> 11:07.470 Don't worry. 11:07.470 --> 11:12.210 After I probably make you understand all these things, then we will be seeing more examples as we go 11:12.240 --> 11:12.450 ahead. 11:12.480 --> 11:17.250 Okay, now with respect to the loop control statement, first of all, we will discuss about something 11:17.250 --> 11:18.180 called as break. 11:18.210 --> 11:18.750 Okay. 11:18.780 --> 11:23.850 Now if you really want to understand break I'll just go ahead and write this definition. 11:23.850 --> 11:26.550 The break statement exists. 11:26.730 --> 11:29.670 Exits the loop. 11:30.810 --> 11:31.380 Permanent. 11:33.030 --> 11:36.420 Uh, exits the loop prematurely. 11:36.450 --> 11:36.780 Okay. 11:36.810 --> 11:38.160 What does this basically mean? 11:38.160 --> 11:39.270 I will just make you understand. 11:39.300 --> 11:39.810 Okay. 11:40.800 --> 11:43.980 Let's say I want to write a break statement. 11:44.010 --> 11:45.990 Now, how do I write a break statement? 11:46.410 --> 11:50.340 So first of all, let's say I am going to run for I in range. 11:50.370 --> 11:51.030 Okay. 11:51.240 --> 11:54.840 Please make sure that you understand the syntax for I in range. 11:54.840 --> 11:56.010 Range of the collection. 11:56.010 --> 11:57.660 This is nothing, but this is collection. 11:57.660 --> 11:58.590 It can be a list. 11:58.590 --> 11:59.370 It can be a dictionary. 11:59.400 --> 12:00.060 It can be range. 12:00.060 --> 12:00.810 It can be string. 12:00.810 --> 12:01.750 Anything it can be. 12:01.780 --> 12:03.430 And let's say I'm writing ten. 12:03.430 --> 12:07.060 So ten basically means it is going to iterate from 0 to 1 okay. 12:07.180 --> 12:12.730 For one of the condition I'll say if I is double equal to five okay. 12:12.820 --> 12:19.750 If this I is equal to five I don't want to probably or I want to come outside this particular loop okay. 12:19.780 --> 12:22.300 I want to come outside this entire for loop. 12:22.300 --> 12:24.940 So I will go ahead and just write break okay. 12:25.060 --> 12:27.550 And once we probably write break okay. 12:27.550 --> 12:31.480 It is probably going to come outside of this particular for loop itself. 12:31.480 --> 12:31.900 Right. 12:31.930 --> 12:33.190 Now one more thing. 12:33.190 --> 12:36.640 If I is not equal to five at that time, we just need to print I. 12:36.670 --> 12:36.880 Okay. 12:36.910 --> 12:41.710 So now see what is this entire code that I have actually written for I in range of ten. 12:41.710 --> 12:46.330 If I is double equal to five, I am saying only when I is equal to five do. 12:46.330 --> 12:49.360 The break statement comes outside of this particular for loop. 12:49.360 --> 12:52.660 When I is not equal to five, you just need to keep on printing the numbers. 12:52.690 --> 12:53.020 Okay? 12:53.050 --> 12:57.700 So now if I go ahead and execute it here, you'll be able to see 012345. 12:57.880 --> 13:02.690 Then when five came automatically we came outside of this particular for loop. 13:02.720 --> 13:02.930 Okay. 13:02.960 --> 13:05.240 And then after that, nothing is getting printed. 13:05.240 --> 13:09.530 So we are executing this particular loop permanently. 13:09.560 --> 13:10.040 Okay. 13:10.070 --> 13:12.800 Permanently with the help of break over here. 13:13.220 --> 13:17.990 But this break will only get applied on any statement on any condition as such. 13:18.020 --> 13:18.410 Right. 13:18.410 --> 13:22.220 So that is why we are specifically using this break statement. 13:22.250 --> 13:22.790 Okay. 13:23.180 --> 13:25.670 Uh, this is one of the good examples. 13:25.670 --> 13:30.950 Uh, again, uh, now with respect to the another loop control statement, we also have something called 13:30.950 --> 13:31.790 as continue. 13:32.150 --> 13:32.630 Okay. 13:32.630 --> 13:35.120 So now we will go ahead and write continue. 13:35.150 --> 13:37.400 Now what exactly continue is okay. 13:37.430 --> 13:42.470 And you also need to know this if I really want to define continue. 13:42.500 --> 13:43.040 Okay. 13:43.070 --> 13:43.730 Continue. 13:43.760 --> 13:47.570 Statement skips the current iteration and continues with the next. 13:47.600 --> 13:48.080 Okay. 13:48.080 --> 13:51.710 So that basically means let's say I'm going to write for I in range. 13:51.740 --> 13:52.370 Okay. 13:52.400 --> 13:55.910 For I in range for I in range. 13:55.910 --> 13:58.640 And let's say I write some elements over here ten. 13:58.670 --> 13:59.210 Okay. 13:59.210 --> 14:06.350 And now if I go ahead and write if I modulus two right is double equal to zero okay. 14:06.800 --> 14:10.610 And this condition is basically just to check whether the number is even or not. 14:10.640 --> 14:15.380 If the number is even let's say that I will go ahead and write continue okay. 14:15.410 --> 14:17.120 I will just go ahead and write continue. 14:17.150 --> 14:23.090 And then I will just go over here and print I okay. 14:23.120 --> 14:29.660 Now in short, if I really want to make you understand, this is just like displaying all the odd numbers 14:29.660 --> 14:31.880 between 0 to 10, right? 14:31.910 --> 14:33.350 Do you agree with me or not? 14:33.380 --> 14:38.990 See what I'm doing over here for I in range of ten if I percentile if I modulus two is equal to zero, 14:39.020 --> 14:40.430 that basically means this is an even number. 14:40.460 --> 14:41.630 We are just going to continue. 14:41.900 --> 14:44.960 Otherwise if it is not which is an odd number, we are just going to print it. 14:44.990 --> 14:50.660 So if I go ahead and execute this you'll be able to see that I will only get an odd number 13579 between 14:50.660 --> 14:51.470 0 to 10. 14:51.500 --> 14:51.830 Right. 14:51.860 --> 14:55.220 And that is what is a continue example with respect to continue. 14:55.250 --> 14:57.650 We are just we are just skipping the current iteration. 14:57.650 --> 14:58.640 This will just skip. 14:58.670 --> 15:00.530 It will even not go to the print statement. 15:00.560 --> 15:02.610 It will just go ahead and continue the loop. 15:02.640 --> 15:03.060 Right. 15:03.060 --> 15:06.960 So this is what is the power with respect to the continuous statement. 15:06.990 --> 15:12.300 There is also one more amazing flow control that we use that is basically called as pass. 15:12.330 --> 15:12.930 Okay. 15:12.930 --> 15:17.190 And you should know all these things because some or the other way we will be using all these things 15:17.190 --> 15:17.760 right. 15:18.000 --> 15:23.760 Further when we'll be seeing multiple example, the pass statement is a null operation and it does nothing 15:23.790 --> 15:24.210 okay. 15:24.240 --> 15:25.320 It does nothing. 15:25.320 --> 15:27.120 Nothing means nothing right. 15:27.150 --> 15:31.440 It will just say, hey, I don't want to do anything on a specific condition, okay? 15:31.470 --> 15:41.460 So now if we go ahead and write for I in range for I in range of five, let's say okay for I in range 15:41.460 --> 15:41.940 of five. 15:41.940 --> 15:44.520 Let's say I'm giving this particular condition okay. 15:44.550 --> 15:52.230 I'm saying hey if I is equal to three, if I is double equal to three okay. 15:52.260 --> 15:55.350 Then I'm saying hey just pass okay. 15:55.380 --> 15:56.760 Do nothing okay. 15:56.790 --> 15:59.940 I don't want you to do anything over here, okay? 15:59.970 --> 16:03.320 And then we are going to print I. 16:03.350 --> 16:03.620 Okay. 16:03.650 --> 16:06.290 Now see what will happen in this particular case. 16:06.290 --> 16:10.490 Whenever I say hey, whenever the number is even, just skip this for loop. 16:10.490 --> 16:13.310 But here it is saying do nothing, just go ahead. 16:13.340 --> 16:13.820 Right? 16:13.820 --> 16:16.400 Just go ahead and skip it right now. 16:16.400 --> 16:18.590 If I go ahead and execute it now, see what is happening. 16:18.620 --> 16:22.910 Zero is getting displayed, one is getting displayed, two is getting displayed. 16:22.910 --> 16:24.050 When I is three. 16:24.080 --> 16:25.970 Again, I'm just saying hey, skip it. 16:25.970 --> 16:27.980 So it has just skipped this if loop, right. 16:28.010 --> 16:33.080 Or the best way will be to print something like this okay. 16:33.170 --> 16:39.680 The number is okay I will write number is over here as I okay. 16:39.710 --> 16:41.300 Now you'll be able to understand this. 16:41.330 --> 16:46.220 Now this pass as soon as we do the pass right at that time, what will happen now? 16:46.220 --> 16:49.040 First of all, see when I is equal to three it only this will get printed. 16:49.040 --> 16:50.750 And we are just going to skip this okay. 16:50.780 --> 16:52.400 Or do nothing as such. 16:52.400 --> 16:54.320 So here you can see 0123. 16:54.320 --> 16:56.450 The number is 334. 16:56.480 --> 16:56.960 Right. 16:56.990 --> 16:58.040 Pass in. 16:58.070 --> 16:59.540 It's just like a null statement. 16:59.540 --> 17:01.670 Suppose I don't have anything to give over here. 17:01.670 --> 17:04.370 I will just remove this and I will just write pass. 17:04.400 --> 17:05.420 Do nothing as such. 17:05.450 --> 17:05.870 Okay. 17:05.870 --> 17:08.060 So this can also be useful. 17:08.060 --> 17:09.740 And again I will talk about it. 17:09.800 --> 17:12.470 What exactly will be the use case over here. 17:12.620 --> 17:13.100 Right. 17:13.100 --> 17:19.910 But most of them if I probably consider pass continue or let's say if I'm probably defining an empty 17:19.940 --> 17:25.760 function and if I define an empty function, and if I internally write write just pass. 17:25.760 --> 17:27.620 That basically means that the function does nothing. 17:27.650 --> 17:28.070 Okay. 17:28.100 --> 17:32.000 So this is some of the amazing things that have been brought by Python. 17:32.210 --> 17:36.890 Uh, if I talk about break, this will be very handy because on a certain condition we are just going 17:36.890 --> 17:38.840 to break this or come out of this particular loop. 17:38.840 --> 17:39.800 We can use break. 17:39.830 --> 17:41.030 Then we have continue. 17:41.060 --> 17:42.590 Then we have pass. 17:42.620 --> 17:47.090 Right now let's talk about nested loops okay. 17:47.090 --> 17:50.180 So let's talk about nested loops. 17:51.530 --> 17:57.530 Nested loop is nothing but a loop inside a loop right. 17:58.400 --> 18:05.060 Let's say I will run a loop for I in range three. 18:05.660 --> 18:06.320 Okay. 18:06.380 --> 18:09.950 And let's say for J in range two. 18:10.520 --> 18:10.850 Okay. 18:10.880 --> 18:12.050 Now what I'm doing. 18:12.740 --> 18:14.720 And let's say I go ahead and print. 18:15.560 --> 18:16.520 Print. 18:16.520 --> 18:21.320 And here with respect to the print statement let me show you how you can use f string also. 18:21.350 --> 18:23.570 So f f string is nothing. 18:23.570 --> 18:25.940 But here I'm basically writing it out. 18:25.970 --> 18:35.270 And here I'll write I is equal to will be equal to I and j equal to it will be equal to j okay. 18:35.300 --> 18:41.210 So whenever we use this f string formatted statement to display the variables we have to use this curly 18:41.210 --> 18:41.930 braces. 18:41.930 --> 18:46.310 And in short this is just a formatting option of displaying the string. 18:46.310 --> 18:52.220 I can use this particular string together along with uh you know, flower braces so that I can display 18:52.220 --> 18:53.240 that particular variable. 18:53.270 --> 18:55.370 Now, what is exactly happening over here? 18:56.210 --> 18:57.560 See, it is very simple. 18:57.890 --> 19:02.280 Uh, over here, you'll be able to see for I in range of three. 19:02.310 --> 19:02.790 Right. 19:02.790 --> 19:05.220 I'm iterating through another range over here. 19:05.220 --> 19:07.110 Another iterate over here. 19:07.110 --> 19:10.140 Then I'm also running another iteration over here. 19:10.170 --> 19:10.440 Right. 19:10.440 --> 19:12.060 So there are three elements over here. 19:12.060 --> 19:13.740 So first it will run this. 19:13.740 --> 19:15.090 Then it will go inside this. 19:15.090 --> 19:20.040 And it will complete the inner loop right inner inner loop inner inner for loop. 19:20.040 --> 19:21.750 Then it will go to the outside for loop. 19:21.750 --> 19:25.710 So first time when it gets displayed this is going to get executed for the two times. 19:25.710 --> 19:29.430 Then it will going to go and increment the I to two. 19:29.460 --> 19:34.890 Then again it is going to uh run it for two times for this particular loop. 19:34.890 --> 19:39.300 If you don't know, if you don't understand, see over here, I'll show you with respect to the output. 19:39.300 --> 19:42.870 So here initially you can see when I is zero J is zero. 19:42.900 --> 19:45.660 Because initially when we are running this particular loop. 19:45.690 --> 19:46.020 Right. 19:46.050 --> 19:49.230 And then when we go inside this particular loop J will run for two times. 19:49.230 --> 19:51.930 So j is running for j is equal to zero, j is equal to one. 19:51.960 --> 19:53.610 Then you have I is equal to one. 19:53.610 --> 19:55.740 Then again j is equal to zero, j is equal to one. 19:55.740 --> 19:56.310 Then you have. 19:56.310 --> 19:59.310 When I is incremented to two, j is equal to zero and j is equal to one. 19:59.310 --> 20:02.680 So it is basically going to run with respect to all the inner loops. 20:02.710 --> 20:03.070 Right. 20:03.070 --> 20:07.990 And here this for loop, every time it will be executed based on the number of range that I've actually 20:07.990 --> 20:08.800 given over here. 20:08.830 --> 20:09.190 Right. 20:09.190 --> 20:13.030 Whenever we insert enter the upper for loop itself. 20:13.060 --> 20:13.420 Right. 20:13.420 --> 20:17.590 So this is just an example of a for loops over here. 20:17.710 --> 20:18.520 Uh sorry. 20:18.550 --> 20:20.950 Nested loops over here right now. 20:20.950 --> 20:23.650 Let us go ahead and see some examples okay. 20:23.680 --> 20:26.500 And this is where we will practice multiple things. 20:26.980 --> 20:32.770 Uh, the first examples that we are going to do is that, uh, let's say I am going to write over here, 20:32.800 --> 20:46.270 calculate the sum of first n natural numbers using a while loop, using a while and for loop. 20:46.660 --> 20:47.230 Okay. 20:47.230 --> 20:51.670 So let me just go ahead and first of all show you with the help of uh while loop okay. 20:51.670 --> 20:54.070 So first we'll see with respect to the while loop. 20:54.070 --> 20:58.210 And then we will go ahead and see with respect to the for loop okay. 20:58.240 --> 21:02.260 What we need to do, calculate the sum of first n and natural numbers. 21:02.290 --> 21:02.530 Okay. 21:02.560 --> 21:03.880 First n natural numbers. 21:03.880 --> 21:04.690 Very simple. 21:04.720 --> 21:11.230 So now I will just go ahead and say, let's say that the number of a n number the natural number is 21:11.230 --> 21:11.710 ten. 21:11.740 --> 21:15.280 Then initially I will define my some variable to zero. 21:15.310 --> 21:20.020 This will be my temporary variable because the addition that I'm going to do with respect to all the 21:20.020 --> 21:24.100 natural numbers, I'm going to save it in this particular variable called as sum. 21:24.190 --> 21:29.140 Then I will keep this temporary variable called as count is equal to one okay. 21:29.470 --> 21:31.660 Now let's go ahead. 21:31.690 --> 21:31.900 Okay. 21:31.930 --> 21:39.130 So here I'm going to write while okay count is less than or equal to n right. 21:39.430 --> 21:45.550 Unless until the count is less than or equal to n I'm going to just go ahead and I'm going to use this 21:45.550 --> 21:48.940 sum is equal to sum plus count. 21:48.970 --> 21:49.510 Right. 21:49.510 --> 21:52.660 So what we are doing over here we are keep on adding the count. 21:52.690 --> 21:52.990 Right. 21:53.020 --> 21:55.990 Unless and until this is not equal to less than or equal to n. 21:55.990 --> 21:57.910 And after this we will go ahead and write. 21:57.940 --> 22:00.370 Count is equal to count plus one. 22:00.370 --> 22:02.420 We are incrementing the count variable also. 22:02.450 --> 22:07.100 And finally, when this for loop is, a while loop is getting completed. 22:07.130 --> 22:14.390 I will write sum of first ten natural numbers. 22:15.080 --> 22:21.770 Okay, natural numbers will be equal to nothing but whatever sum we are probably getting over here, 22:21.800 --> 22:22.190 right? 22:22.220 --> 22:23.930 Just go through the statements here. 22:23.930 --> 22:27.200 We have initialized how many number of natural numbers we are going to consider. 22:27.200 --> 22:29.930 Initially, the sum is equal to zero, count is equal to one. 22:29.930 --> 22:35.090 Now I am saying while count is less than or equal to n, I'm going to increment this count continuously 22:35.090 --> 22:40.670 unless and until this gets satisfied, then automatically internally we are doing the sum also. 22:40.700 --> 22:41.120 Okay. 22:41.150 --> 22:44.510 So here you can actually see the sum of first n ten. 22:44.510 --> 22:47.480 Natural numbers is nothing but 55 perfect. 22:47.480 --> 22:53.420 So this is just like one plus two plus three plus four plus five plus six plus seven plus eight plus 22:53.420 --> 22:54.410 nine plus ten. 22:54.440 --> 22:55.010 Right. 22:55.250 --> 22:56.450 Uh, it will not go. 22:56.600 --> 22:59.810 Yeah, it will go till ten because we have written less than or equal to n. 22:59.840 --> 23:00.500 Okay. 23:00.500 --> 23:01.250 Perfect. 23:01.250 --> 23:03.060 So this was one of the example. 23:03.180 --> 23:05.700 Let's do it the same thing with the help of for loop. 23:05.700 --> 23:06.570 So I will write. 23:06.600 --> 23:12.330 Uh, so let me just go ahead and define this three variables again okay. 23:12.930 --> 23:17.460 So let's say for I in range. 23:17.490 --> 23:24.450 And here also I can just go ahead and write till 11 because I want to probably do from zero to 0 to 23:24.450 --> 23:25.410 10 okay. 23:25.440 --> 23:29.970 And here I'll just go ahead and write sum is equal to sum plus I. 23:30.000 --> 23:30.840 That's it. 23:30.870 --> 23:31.380 Right. 23:31.380 --> 23:33.480 And here I don't even have to write. 23:33.480 --> 23:35.010 This count is equal to one okay. 23:35.040 --> 23:39.360 Because automatically this will get integrated in uh uh incremented. 23:39.360 --> 23:42.450 So here let me just go ahead and print the sum. 23:42.450 --> 23:46.590 And if I go ahead and execute I'm also able to get it 55 okay. 23:46.590 --> 23:53.550 So here I've shown you with the help of both while and for loop how you can calculate the first ten 23:53.550 --> 23:56.160 natural uh numbers sum. 23:56.160 --> 23:57.930 And here you are able to see it. 23:57.960 --> 23:58.440 Okay. 23:58.500 --> 23:59.850 Now let me do one thing. 23:59.850 --> 24:02.070 Let me show you one more example. 24:02.100 --> 24:10.740 Okay, now this time the examples will be talk about the prime numbers or display the prime numbers 24:10.740 --> 24:12.960 between 1 and 100. 24:12.990 --> 24:14.220 Now what is prime number? 24:14.220 --> 24:18.300 Prime number are something which is divisible by one or the number itself. 24:18.330 --> 24:18.870 Right. 24:18.900 --> 24:22.560 Now, uh, here I'll just go ahead and write it down. 24:22.560 --> 24:24.510 And again for this I will use a for loop. 24:24.510 --> 24:29.700 So I'll write for num in range of one comma 101. 24:29.730 --> 24:29.910 Right. 24:29.940 --> 24:33.300 Because we need the numbers between 1 and 100 right. 24:33.510 --> 24:38.940 If the first condition will be that, I will go ahead and write if num is greater than one, right. 24:38.970 --> 24:41.070 Obviously the number has to be greater than one. 24:41.070 --> 24:42.510 So one condition is over here. 24:42.540 --> 24:45.690 We are going to use if nested if nested for loops. 24:45.690 --> 24:45.810 And. 24:45.840 --> 24:46.530 All right. 24:46.650 --> 24:50.940 Please pause the video, try it by yourself and then probably see the solution. 24:50.970 --> 24:51.420 Okay. 24:51.450 --> 24:57.690 Now if this is true then what I'll do for I in range two comma num. 24:57.720 --> 24:58.380 Okay. 24:58.890 --> 25:02.530 Uh, for I in range two common norm. 25:02.530 --> 25:07.240 That basically means from this number, from two to this particular number, whichever number we are 25:07.240 --> 25:13.510 specifically discussing, or from this for loop, which number I'm able to increment, I will just go 25:13.540 --> 25:15.880 ahead and write this particular condition. 25:15.880 --> 25:23.770 If num percentile I write, I is the same number over there, right is equal to zero. 25:23.800 --> 25:26.740 Then we are just going to break it okay. 25:26.740 --> 25:31.870 And then we are just going to break and come outside this for loop. 25:31.870 --> 25:35.980 And I'm going to say else print number okay. 25:36.940 --> 25:38.200 We are just need to print this. 25:38.200 --> 25:40.210 Because if this gets satisfied right. 25:40.210 --> 25:44.050 This is basically indicating that hey I've got a prime number. 25:44.080 --> 25:44.560 Right. 25:44.560 --> 25:46.990 And then it is just going to display the prime number. 25:46.990 --> 25:49.780 So again I'm repeating first of all I'm going to check a condition. 25:49.780 --> 25:55.030 If number is greater than one then we are going to write for I in range of two comma num okay two comma 25:55.030 --> 25:55.420 num. 25:55.420 --> 25:59.740 So we are incrementing the so so we are running through this particular two comma num. 25:59.740 --> 26:01.000 Whatever num is there. 26:01.030 --> 26:03.080 Let's say the number is three. 26:03.080 --> 26:05.540 So two comma three for range in two comma three. 26:05.540 --> 26:09.740 Then we can go ahead and write three percentile two is double equal to zero. 26:09.770 --> 26:11.360 The answer is no right. 26:11.360 --> 26:14.210 If it is no we are just going to go ahead and display this number. 26:14.240 --> 26:14.720 Right. 26:14.720 --> 26:19.700 And if it breaks it is just going to go outside this particular for loop okay. 26:19.700 --> 26:23.570 So that basically means if this condition is becoming true right. 26:23.570 --> 26:26.660 That basically means it is not a prime number. 26:26.690 --> 26:29.780 Otherwise we are just going to display the number in the else block. 26:29.810 --> 26:30.320 Okay. 26:30.380 --> 26:35.780 And one more thing about for loop is that along with the for loop also you can write else block right 26:35.810 --> 26:41.930 else block if something uh you don't want to execute it, but you want to execute compulsory at the 26:41.930 --> 26:42.950 end of the for loop. 26:42.950 --> 26:44.990 So you can also use this else block okay. 26:45.020 --> 26:47.960 So once I execute this here you'll be able to see two three. 26:47.960 --> 26:54.260 So two is a prime number three is a prime number five seven is a prime number 11 1317 1923, 29. 26:54.290 --> 26:55.580 All these are prime numbers. 26:55.580 --> 26:57.710 You can probably go ahead and check it out okay. 26:58.010 --> 27:02.150 Uh these are like numbers which are only divisible by one or the number itself. 27:02.180 --> 27:02.390 Right. 27:02.420 --> 27:04.310 So here you can actually see the example. 27:04.370 --> 27:04.880 Okay. 27:05.060 --> 27:10.430 Now some more uh uh examples that you will be seeing as we go ahead. 27:10.460 --> 27:16.520 But where we'll be using when we learn more about uh, different different data structures like lists 27:16.520 --> 27:17.300 and dictionary. 27:17.300 --> 27:22.100 But at the end, uh, conclusion that I really want to give after every lesson. 27:22.130 --> 27:22.610 Right. 27:22.610 --> 27:25.910 And let me make a markdown cell over here. 27:25.970 --> 27:26.600 Okay. 27:27.260 --> 27:31.010 So conclusion is that loops are really powerful. 27:31.340 --> 27:31.850 Okay. 27:31.880 --> 27:35.000 Loops are definitely very, very powerful. 27:35.030 --> 27:35.720 Okay. 27:35.990 --> 27:41.450 Um, in Python that allows you to execute block of code multiple times by understanding, using for 27:41.450 --> 27:44.240 and while loops along with the loop control statement like break, continue, and pass. 27:44.240 --> 27:49.370 You can handle a wide range of programming tasks efficiently, and you'll be seeing that when we will 27:49.400 --> 27:51.140 be discussing about more examples. 27:51.140 --> 27:56.510 But I really want to keep the video between 20 to 25 minutes, where I show you multiple examples where 27:56.510 --> 27:59.990 I write each line of code in front of you so that you will also be able to understand. 27:59.990 --> 28:01.430 So yes, this was it from my side. 28:01.430 --> 28:02.630 I'll see you all in the next video. 28:02.630 --> 28:02.930 Thank you.