1 00:00:00,000 --> 00:00:01,000 Hello guys. 2 00:00:01,000 --> 00:00:03,000 So we are going to continue the discussion with respect to Python. 3 00:00:03,000 --> 00:00:08,000 And now we are going to discuss about our new data structure which is called as dictionaries. 4 00:00:08,000 --> 00:00:13,000 So in this video this is the entire video outline where we will be discussing about the introduction 5 00:00:13,000 --> 00:00:13,000 to dictionaries. 6 00:00:13,000 --> 00:00:16,000 We will be creating dictionaries with the help of Python. 7 00:00:16,000 --> 00:00:20,000 How to access the dictionary elements, modifying dictionary elements. 8 00:00:21,000 --> 00:00:26,000 Then we'll be seeing some of the amazing dictionary methods that we usually use while we are developing 9 00:00:26,000 --> 00:00:27,000 projects. 10 00:00:27,000 --> 00:00:30,000 Along with that, we'll also be iterating over dictionaries. 11 00:00:31,000 --> 00:00:35,000 Then we will be discussing about nested dictionaries, then dictionary comprehension. 12 00:00:35,000 --> 00:00:40,000 And finally we will be seeing some of the common errors that we usually face. 13 00:00:40,000 --> 00:00:46,000 Now in this it is very much important that we probably do a lot of practicals. 14 00:00:46,000 --> 00:00:50,000 So that is the reason I will be showing you each and every thing with the help of coding. 15 00:00:50,000 --> 00:00:51,000 Now let me go ahead. 16 00:00:51,000 --> 00:00:55,000 And first of all, uh, let's see the definition of dictionaries. 17 00:00:55,000 --> 00:00:59,000 So dictionaries are nothing, but it is an unordered collection of items. 18 00:00:59,000 --> 00:01:02,000 The store data in key value pairs. 19 00:01:02,000 --> 00:01:02,000 Okay. 20 00:01:02,000 --> 00:01:08,000 So they're all the data is basically stored in key value pairs. 21 00:01:08,000 --> 00:01:10,000 Key must be unique and immutable. 22 00:01:10,000 --> 00:01:14,000 So once you specifically define a key it cannot be changed. 23 00:01:14,000 --> 00:01:19,000 Values can be changed and key must always be unique, okay? 24 00:01:19,000 --> 00:01:26,000 And it can include strings, numbers or tuples uh which while values can be of any type okay. 25 00:01:26,000 --> 00:01:30,000 So let me just go ahead and I hope you have just understood the definition. 26 00:01:30,000 --> 00:01:35,000 But again to make you understand much more in a better way, first of all, we will go ahead, uh, 27 00:01:35,000 --> 00:01:38,000 in discussing about creating dictionaries. 28 00:01:38,000 --> 00:01:38,000 Okay. 29 00:01:38,000 --> 00:01:43,000 Now with respect to creating dictionaries, first of all, what we are really going to do over here 30 00:01:43,000 --> 00:01:46,000 is that create an empty dictionary. 31 00:01:46,000 --> 00:01:49,000 Now, already, you know, if I use square braces okay. 32 00:01:49,000 --> 00:01:51,000 And before that make sure you select the kernel. 33 00:01:52,000 --> 00:01:58,000 Uh, so if you are basically using this square brackets then you basically create an empty list. 34 00:01:58,000 --> 00:02:01,000 If you are using tuples you create an empty tuple. 35 00:02:01,000 --> 00:02:05,000 Now in case of dictionary we use flower braces okay. 36 00:02:05,000 --> 00:02:09,000 Now now let's go ahead and define and create our empty dictionary. 37 00:02:09,000 --> 00:02:18,000 So here you can see if I go ahead and print type of empty dictionary, you will be able to see that 38 00:02:18,000 --> 00:02:21,000 I will be getting a class which is called as dictionary. 39 00:02:21,000 --> 00:02:27,000 So in order to create an empty dictionary, all we have to do is that we have to specifically use this 40 00:02:27,000 --> 00:02:27,000 flower braces. 41 00:02:28,000 --> 00:02:28,000 Okay. 42 00:02:28,000 --> 00:02:36,000 Another way how we can actually create our empty dictionary is that by using this dict class okay. 43 00:02:36,000 --> 00:02:39,000 And here we will initialize it as a method. 44 00:02:39,000 --> 00:02:41,000 So once we initialize it here you'll be able to see. 45 00:02:41,000 --> 00:02:46,000 Now again I will be getting an complete empty dictionary okay. 46 00:02:46,000 --> 00:02:48,000 So right now it is a complete empty dictionary. 47 00:02:48,000 --> 00:02:55,000 So these are the two ways of specifically creating an empty dictionary Now, as I have already said, 48 00:02:55,000 --> 00:02:58,000 that dictionary is all about key value pairs. 49 00:02:58,000 --> 00:03:02,000 Right now, whenever we talk about key value pairs, let me just give you an example. 50 00:03:02,000 --> 00:03:03,000 So key. 51 00:03:03,000 --> 00:03:07,000 So initially we will you start writing in this flower brackets. 52 00:03:07,000 --> 00:03:12,000 So first of all what we are going to do is that we are going to give my key name, let's say one of 53 00:03:12,000 --> 00:03:15,000 the key name with respect to student information is name. 54 00:03:15,000 --> 00:03:18,000 And let me just go ahead and write the name called as Krish. 55 00:03:18,000 --> 00:03:18,000 Okay. 56 00:03:18,000 --> 00:03:20,000 So Krish is the name. 57 00:03:20,000 --> 00:03:21,000 So this basically becomes the key. 58 00:03:21,000 --> 00:03:23,000 This basically becomes the value. 59 00:03:23,000 --> 00:03:23,000 Okay. 60 00:03:24,000 --> 00:03:28,000 Now the next thing is that I will go ahead and use my another key which is called as age. 61 00:03:29,000 --> 00:03:30,000 Okay. 62 00:03:30,000 --> 00:03:34,000 And here we are specifically going to use a value let's say 32 okay. 63 00:03:34,000 --> 00:03:39,000 Third I'm just going to use another key which is called as grade. 64 00:03:39,000 --> 00:03:45,000 Now if I go ahead and write this you'll be able to see if I go ahead and print this student. 65 00:03:45,000 --> 00:03:52,000 This is a complete dictionary where I have three keys, that is name, age and grade, and the values 66 00:03:52,000 --> 00:03:55,000 are crush 32 and 24. 67 00:03:56,000 --> 00:03:57,000 Now if I go ahead and print the student. 68 00:03:57,000 --> 00:04:01,000 So this basically becomes my entire dictionary right? 69 00:04:01,000 --> 00:04:02,000 Which has this key value pairs. 70 00:04:02,000 --> 00:04:09,000 If you want to also check out the print off type of student, you will also be able to see that I'm 71 00:04:09,000 --> 00:04:11,000 able to get a dictionary over here. 72 00:04:11,000 --> 00:04:17,000 Okay, so this is how you specifically create a dictionary with the help of key value pairs. 73 00:04:17,000 --> 00:04:18,000 Okay. 74 00:04:18,000 --> 00:04:21,000 Now let me just show you one more thing here. 75 00:04:21,000 --> 00:04:22,000 When do you get an error. 76 00:04:22,000 --> 00:04:26,000 Because as I said you that key should be unique okay. 77 00:04:26,000 --> 00:04:31,000 So let's say if I go ahead and copy this and paste it over here and again I use the same name. 78 00:04:31,000 --> 00:04:33,000 Now what is going to happen. 79 00:04:33,000 --> 00:04:33,000 Okay. 80 00:04:33,000 --> 00:04:36,000 And I'll just go ahead and print student. 81 00:04:36,000 --> 00:04:40,000 Let's see what is going to happen. 82 00:04:40,000 --> 00:04:45,000 Because you really need to understand whether we will get an error or whether it will just print out. 83 00:04:45,000 --> 00:04:49,000 So here you can see only two keys are basically getting their name and age right. 84 00:04:49,000 --> 00:04:51,000 Name is having the value of 24. 85 00:04:51,000 --> 00:04:52,000 Age is 32. 86 00:04:52,000 --> 00:04:54,000 Now what has exactly happened over here? 87 00:04:54,000 --> 00:04:57,000 Now when I'm writing name is equal to Krish. 88 00:04:57,000 --> 00:04:59,000 This was one of the key that I have already defined. 89 00:04:59,000 --> 00:05:05,000 Now, if I'm again defining this particular key, you know, in the upcoming like or in the key value 90 00:05:05,000 --> 00:05:09,000 pairs, then what it is going to do, the value is getting going to get replaced. 91 00:05:09,000 --> 00:05:10,000 Okay. 92 00:05:10,000 --> 00:05:13,000 But it is going to consider as one key itself. 93 00:05:13,000 --> 00:05:18,000 So which is the recent value that you have replaced over here, the value that is what is getting displayed. 94 00:05:18,000 --> 00:05:24,000 So always please make sure that here you don't have to always create the key with the same name. 95 00:05:24,000 --> 00:05:29,000 I'll not say this as an error, but here you can see that, uh, I can just write. 96 00:05:29,000 --> 00:05:31,000 Single key is always used okay. 97 00:05:32,000 --> 00:05:33,000 Instead of multiple keys. 98 00:05:33,000 --> 00:05:35,000 So this is one super example. 99 00:05:35,000 --> 00:05:41,000 And this will be very much important because see, um, if you know about databases now NoSQL databases 100 00:05:41,000 --> 00:05:47,000 like MongoDB, like Cassandra over there, all key value pairs will be specifically used, right? 101 00:05:47,000 --> 00:05:49,000 All your data will be stored in key value pairs. 102 00:05:49,000 --> 00:05:53,000 So it is important that we always need to have this key unique. 103 00:05:53,000 --> 00:06:02,000 Right now let me just go ahead and let me talk about accessing dictionary elements okay. 104 00:06:02,000 --> 00:06:05,000 Now with respect to accessing dictionary elements. 105 00:06:05,000 --> 00:06:12,000 Now what I'm actually going to do, let me just go ahead and make this as, uh, I'll just copy this. 106 00:06:13,000 --> 00:06:13,000 Okay. 107 00:06:13,000 --> 00:06:16,000 And let me copy this over here. 108 00:06:17,000 --> 00:06:17,000 Oops. 109 00:06:17,000 --> 00:06:18,000 Not here. 110 00:06:18,000 --> 00:06:18,000 Sorry. 111 00:06:18,000 --> 00:06:19,000 Here. 112 00:06:19,000 --> 00:06:21,000 And let me just make this grade as a. 113 00:06:22,000 --> 00:06:22,000 Okay. 114 00:06:23,000 --> 00:06:27,000 Now, this is my entire dictionary, right? 115 00:06:27,000 --> 00:06:32,000 Now, if I want to access any value, let's say I want to access the value of grade. 116 00:06:32,000 --> 00:06:32,000 Okay. 117 00:06:32,000 --> 00:06:34,000 Now how do I do it? 118 00:06:34,000 --> 00:06:36,000 We definitely have to use this key. 119 00:06:36,000 --> 00:06:44,000 So what I will be doing is that I will just say student of I want the grade of this particular student. 120 00:06:44,000 --> 00:06:49,000 So I will just give the key name over here and let me just go ahead and print it. 121 00:06:49,000 --> 00:06:49,000 Okay. 122 00:06:49,000 --> 00:06:55,000 So here, once I do the print over here right, I should be able to get to see the grade. 123 00:06:55,000 --> 00:06:58,000 Similarly, let's say I want to go ahead and get the age. 124 00:06:59,000 --> 00:07:06,000 So I will go ahead and write student of student of age. 125 00:07:07,000 --> 00:07:07,000 Right. 126 00:07:07,000 --> 00:07:10,000 And if I go ahead and print it it is 32. 127 00:07:10,000 --> 00:07:10,000 Right. 128 00:07:10,000 --> 00:07:20,000 So this is one of the method of accessing I'll write it down over here accessing dictionary elements. 129 00:07:20,000 --> 00:07:20,000 Okay. 130 00:07:20,000 --> 00:07:24,000 This is one of the easiest way to probably do it. 131 00:07:24,000 --> 00:07:33,000 There is also one way where we will be able to access the values using the default get method that is 132 00:07:33,000 --> 00:07:35,000 provided by the dictionary. 133 00:07:35,000 --> 00:07:38,000 Okay, get method that is provided by dictionary. 134 00:07:38,000 --> 00:07:40,000 Now how to do this, I will just show you. 135 00:07:40,000 --> 00:07:44,000 Okay, so first of all I will just go ahead and write Print. 136 00:07:44,000 --> 00:07:47,000 Let's say I want to get the grade right. 137 00:07:47,000 --> 00:07:49,000 What is the grade of this particular student. 138 00:07:49,000 --> 00:07:51,000 So I will just go ahead and use Dot get. 139 00:07:51,000 --> 00:07:55,000 And here I'm just going to give my key name that is dot grade okay. 140 00:07:55,000 --> 00:08:04,000 Similarly let's say if I want to go ahead and print student dot and uh, let's say I want to probably, 141 00:08:05,000 --> 00:08:10,000 um, you know, let's say that there is no, like over here. 142 00:08:10,000 --> 00:08:13,000 The key that are available are name, age, grade. 143 00:08:13,000 --> 00:08:13,000 Right. 144 00:08:13,000 --> 00:08:17,000 Let's say I will go ahead and search for last name. 145 00:08:17,000 --> 00:08:17,000 Okay. 146 00:08:17,000 --> 00:08:19,000 I know the key is not present over there. 147 00:08:19,000 --> 00:08:23,000 So let's see what is the value that I will be getting okay. 148 00:08:23,000 --> 00:08:26,000 And by using get we will be able to get the value anyhow. 149 00:08:26,000 --> 00:08:30,000 But if I execute it here you'll be able to see first student grade. 150 00:08:30,000 --> 00:08:32,000 I got a student age. 151 00:08:32,000 --> 00:08:33,000 I got 32 again. 152 00:08:33,000 --> 00:08:37,000 When I'm writing student dot get of grade, I can get a. 153 00:08:37,000 --> 00:08:42,000 But when I'm searching for last name, I'm not getting anything right. 154 00:08:42,000 --> 00:08:43,000 I'm getting it as none. 155 00:08:43,000 --> 00:08:49,000 Now let's say that, uh, if I find out if I don't find any key, I want to probably give a default 156 00:08:49,000 --> 00:08:49,000 value. 157 00:08:49,000 --> 00:08:56,000 So for that I will go ahead and write print student student Dot. 158 00:08:56,000 --> 00:08:57,000 Get. 159 00:08:57,000 --> 00:08:57,000 Okay. 160 00:08:58,000 --> 00:09:04,000 And here I'm going to specifically write last underscore name I know last number underscore name key 161 00:09:04,000 --> 00:09:05,000 is not available. 162 00:09:05,000 --> 00:09:08,000 But I will give a default value if it is not available. 163 00:09:08,000 --> 00:09:10,000 So I'll write not available. 164 00:09:10,000 --> 00:09:13,000 Now let's see the value that we are going to get. 165 00:09:13,000 --> 00:09:14,000 So see over here. 166 00:09:14,000 --> 00:09:16,000 Last name was not present in this particular key. 167 00:09:16,000 --> 00:09:20,000 So I am getting the default value which I have provided it over here as not available. 168 00:09:20,000 --> 00:09:22,000 So before it was giving us none. 169 00:09:22,000 --> 00:09:25,000 Now it is probably giving us not available. 170 00:09:25,000 --> 00:09:25,000 Right? 171 00:09:25,000 --> 00:09:30,000 So this is how with the help of key, you will be able to access it. 172 00:09:30,000 --> 00:09:34,000 And two ways I have actually shown you how to access dictionary elements. 173 00:09:34,000 --> 00:09:39,000 Either you are directly calling the key or you are using the Get method right. 174 00:09:39,000 --> 00:09:48,000 Now let me just go ahead and let me talk about the next method that is called as modifying dictionary 175 00:09:49,000 --> 00:09:50,000 elements. 176 00:09:50,000 --> 00:09:50,000 Okay. 177 00:09:50,000 --> 00:09:57,000 Now with respect to modifying dictionary elements, one very important key that I really want to write, 178 00:09:57,000 --> 00:09:57,000 right? 179 00:09:57,000 --> 00:10:00,000 Dictionary are mutable right? 180 00:10:00,000 --> 00:10:08,000 So you can add, update, update or delete elements. 181 00:10:08,000 --> 00:10:12,000 Okay, so this is the most important thing about dictionary. 182 00:10:12,000 --> 00:10:13,000 But you cannot see. 183 00:10:13,000 --> 00:10:16,000 You cannot like always all the time. 184 00:10:16,000 --> 00:10:19,000 Your key needs to be unique right at any point of time. 185 00:10:19,000 --> 00:10:23,000 So let me just go ahead and show you some of the examples over here. 186 00:10:23,000 --> 00:10:27,000 So let us go ahead and discuss about modifying dictionary elements. 187 00:10:27,000 --> 00:10:33,000 Uh, so here uh, already, uh, let us go ahead and print this students. 188 00:10:33,000 --> 00:10:34,000 Right. 189 00:10:35,000 --> 00:10:38,000 And, uh, here you can see the name is the key. 190 00:10:38,000 --> 00:10:43,000 The key name, uh, is basically having the value crush age is 32. 191 00:10:43,000 --> 00:10:44,000 Grade is a. 192 00:10:44,000 --> 00:10:46,000 Now let me do one thing. 193 00:10:46,000 --> 00:10:49,000 Let me just go ahead and, uh, add a new key. 194 00:10:49,000 --> 00:10:53,000 I'll also be showing to add a new key and also updating let's say age. 195 00:10:53,000 --> 00:11:01,000 So here now if I go ahead and write student of age and let's say the age is now 33. 196 00:11:01,000 --> 00:11:01,000 Okay. 197 00:11:01,000 --> 00:11:09,000 And uh, I'm just going to print the student now along with that, what I am actually going to do is 198 00:11:09,000 --> 00:11:11,000 that I'm going to add a new key. 199 00:11:11,000 --> 00:11:14,000 And the new key will be something like address. 200 00:11:15,000 --> 00:11:16,000 Okay. 201 00:11:16,000 --> 00:11:20,000 And let me just go ahead and write the address as India. 202 00:11:20,000 --> 00:11:20,000 Okay. 203 00:11:21,000 --> 00:11:23,000 So this is the new key that I'm specifically adding. 204 00:11:23,000 --> 00:11:27,000 Now I will go ahead and print the student. 205 00:11:29,000 --> 00:11:35,000 Now here you can actually see that the first key age has got updated to 33. 206 00:11:35,000 --> 00:11:41,000 Now once it got updated I again added a new key over here which is called as address. 207 00:11:41,000 --> 00:11:47,000 So now I will be able to see the address India that has been added to the same, uh, student dictionary. 208 00:11:47,000 --> 00:11:48,000 Okay. 209 00:11:48,000 --> 00:11:51,000 Along with this, uh, we can also go ahead and delete any key. 210 00:11:51,000 --> 00:11:52,000 Right. 211 00:11:52,000 --> 00:11:56,000 So what I'm actually going to do is that I'm going to delete the key over here. 212 00:11:56,000 --> 00:11:57,000 Okay. 213 00:11:57,000 --> 00:11:59,000 Let's consider that I'm going to delete the grade key. 214 00:11:59,000 --> 00:12:01,000 So let's go ahead and see that. 215 00:12:02,000 --> 00:12:12,000 So here what we have actually done we have updated the value for the key Right here we have added a 216 00:12:12,000 --> 00:12:19,000 new key and value, added a new key and value. 217 00:12:21,000 --> 00:12:27,000 And in the next statement, what I'm actually going to do is that I'm going to delete the key. 218 00:12:27,000 --> 00:12:32,000 So in order to delete the key I just need to use this del keyword okay. 219 00:12:32,000 --> 00:12:36,000 That is available in Python and I will be using the student. 220 00:12:36,000 --> 00:12:38,000 And let me just give the key name. 221 00:12:38,000 --> 00:12:45,000 So if I go ahead and write like this, this will basically delete the key and value pair. 222 00:12:45,000 --> 00:12:46,000 Okay. 223 00:12:46,000 --> 00:12:56,000 Now if I go ahead and print the student, you will be able to see that I will now have the entire key 224 00:12:56,000 --> 00:12:57,000 right? 225 00:12:57,000 --> 00:13:03,000 Grade has got deleted along with the value, and I just have the remaining key that is key value pairs 226 00:13:03,000 --> 00:13:06,000 like name crush, age 33 address India. 227 00:13:06,000 --> 00:13:09,000 Okay, so this is how you delete the key value pair. 228 00:13:09,000 --> 00:13:13,000 So these are some of the operations and how we can modify dictionary elements. 229 00:13:13,000 --> 00:13:13,000 Okay. 230 00:13:14,000 --> 00:13:21,000 Um now let me just go ahead and show you some of the dictionary common dictionary methods that we use. 231 00:13:21,000 --> 00:13:22,000 Okay. 232 00:13:23,000 --> 00:13:29,000 Now you'll be also seeing more examples because after this I will be also showing showing some use cases 233 00:13:29,000 --> 00:13:30,000 examples okay. 234 00:13:30,000 --> 00:13:33,000 So there again we will be discussing more about dictionaries okay. 235 00:13:33,000 --> 00:13:38,000 Now some of the important dictionary methods okay. 236 00:13:38,000 --> 00:13:39,000 So first of all let me just go ahead. 237 00:13:39,000 --> 00:13:44,000 Let's say you just want to get the all the keys of that particular dictionary okay. 238 00:13:44,000 --> 00:13:54,000 So I will go ahead and write keys is equal to student which is my dictionary student dot keys. 239 00:13:54,000 --> 00:13:55,000 Okay. 240 00:13:55,000 --> 00:13:59,000 And let me just go ahead and print all the keys over here. 241 00:13:59,000 --> 00:14:02,000 Okay then let me just go ahead and write. 242 00:14:02,000 --> 00:14:06,000 Values is equal to student dot values. 243 00:14:07,000 --> 00:14:07,000 Okay. 244 00:14:07,000 --> 00:14:14,000 If I want to get the values right off all the dictionary that I have basically in the dictionary, all 245 00:14:14,000 --> 00:14:17,000 the values that I if I want all the values, how can I get it? 246 00:14:17,000 --> 00:14:22,000 So this first code that I've actually written, this will actually help you to get all the keys. 247 00:14:23,000 --> 00:14:23,000 Okay. 248 00:14:23,000 --> 00:14:28,000 And this will actually help you to get all the values okay. 249 00:14:28,000 --> 00:14:33,000 And if I go ahead and print the values I will be able to see the values over here. 250 00:14:34,000 --> 00:14:35,000 Uh, one more. 251 00:14:35,000 --> 00:14:42,000 Uh, let's say I want to get all the key value pairs, let's say in the form of three items. 252 00:14:42,000 --> 00:14:42,000 Okay. 253 00:14:42,000 --> 00:14:46,000 How do I get the key value pairs right in that case. 254 00:14:46,000 --> 00:14:48,000 So let me just go ahead and write. 255 00:14:48,000 --> 00:14:50,000 And I'll define a variable called as items. 256 00:14:50,000 --> 00:14:55,000 And if I go ahead and write student dot items right. 257 00:14:55,000 --> 00:15:01,000 And this will actually help me to get all key value pairs. 258 00:15:01,000 --> 00:15:02,000 Okay. 259 00:15:02,000 --> 00:15:07,000 Now let me just go ahead and print this specific items. 260 00:15:07,000 --> 00:15:08,000 Okay. 261 00:15:08,000 --> 00:15:12,000 So here you can see that uh let's see the first one okay. 262 00:15:12,000 --> 00:15:14,000 Student Dot keys I'm getting all the key. 263 00:15:14,000 --> 00:15:16,000 So name, age and address are the key. 264 00:15:16,000 --> 00:15:18,000 When I wrote student dot values I got all the values. 265 00:15:18,000 --> 00:15:19,000 I'm printing it. 266 00:15:19,000 --> 00:15:21,000 So Krish 33 and India. 267 00:15:21,000 --> 00:15:24,000 And when I want all the key value pairs. 268 00:15:24,000 --> 00:15:26,000 So like this I'm able to get it right. 269 00:15:26,000 --> 00:15:31,000 So this will be a new type which is called as dictionary items which will be in the form of list of 270 00:15:31,000 --> 00:15:31,000 tuples. 271 00:15:31,000 --> 00:15:33,000 So these are nothing but tuples right. 272 00:15:33,000 --> 00:15:35,000 Tuples tuples tuples. 273 00:15:35,000 --> 00:15:37,000 Right I will be able to access this particular tuples also. 274 00:15:37,000 --> 00:15:39,000 And it is a list of tuples okay. 275 00:15:39,000 --> 00:15:44,000 So here you can see name Chris age 33 A address India. 276 00:15:44,000 --> 00:15:46,000 Right now one more thing. 277 00:15:46,000 --> 00:15:50,000 Uh, I really want to do is do a shallow copy. 278 00:15:50,000 --> 00:15:50,000 Okay. 279 00:15:50,000 --> 00:15:53,000 Now let us discuss about shallow copy over here. 280 00:15:53,000 --> 00:15:57,000 So, guys, now let me just go ahead and show you the working of shallow copy. 281 00:15:57,000 --> 00:15:59,000 And this is something really, really important. 282 00:15:59,000 --> 00:16:01,000 And trust me, you should never do this mistake. 283 00:16:01,000 --> 00:16:07,000 Whenever you are implementing in any kind of project, you have to make sure that whenever, uh. 284 00:16:07,000 --> 00:16:12,000 And you need to remember this concept because this can be a very small mistake whenever you're developing 285 00:16:12,000 --> 00:16:13,000 projects. 286 00:16:13,000 --> 00:16:19,000 Okay, now I have student dictionary over here right now. 287 00:16:19,000 --> 00:16:19,000 Let me do one thing. 288 00:16:19,000 --> 00:16:22,000 Let me create another variable. 289 00:16:22,000 --> 00:16:25,000 Let's say I will go ahead and write student underscore copy. 290 00:16:25,000 --> 00:16:27,000 And I will assign the student value over here. 291 00:16:27,000 --> 00:16:32,000 And as you all know what is present in the student the key value pairs. 292 00:16:32,000 --> 00:16:41,000 Right now if I go ahead and print student, and if I go ahead and print student underscore copy okay. 293 00:16:43,000 --> 00:16:45,000 Student underscore copy. 294 00:16:45,000 --> 00:16:47,000 What am I getting? 295 00:16:47,000 --> 00:16:48,000 I'm getting the same value. 296 00:16:48,000 --> 00:16:49,000 This is perfectly fine. 297 00:16:49,000 --> 00:16:54,000 And obviously since I'm copying this particular value to another variable. 298 00:16:54,000 --> 00:16:57,000 So this will also be a dictionary that will be having the same value over here okay. 299 00:16:57,000 --> 00:16:57,000 Okay. 300 00:16:58,000 --> 00:17:04,000 But now what I will do I will just go ahead and take student name value. 301 00:17:05,000 --> 00:17:05,000 Right. 302 00:17:05,000 --> 00:17:08,000 Student name value. 303 00:17:08,000 --> 00:17:11,000 And I will assign some other value itself. 304 00:17:11,000 --> 00:17:11,000 Right. 305 00:17:11,000 --> 00:17:13,000 Let's say crush one okay. 306 00:17:13,000 --> 00:17:19,000 Now let me just go ahead and print student and let me print the same student underscore copy. 307 00:17:20,000 --> 00:17:25,000 What do you think should be the name in student underscore copy? 308 00:17:26,000 --> 00:17:28,000 Should it be Christian or Christian? 309 00:17:28,000 --> 00:17:29,000 Okay, I'll make it to Christian. 310 00:17:29,000 --> 00:17:30,000 Okay. 311 00:17:30,000 --> 00:17:35,000 Let's say I'm changing the name of this particular student right over here to Cristo. 312 00:17:36,000 --> 00:17:41,000 Now, since I'm making the change to this student dictionary, since I made a copy of this in student 313 00:17:41,000 --> 00:17:46,000 underscore copy, then you may be thinking, okay, student underscore copy should still have Christian, 314 00:17:46,000 --> 00:17:47,000 but it does not happen in that way. 315 00:17:47,000 --> 00:17:52,000 If I go ahead and see the output, you'll be seeing that since student also got the name as Krish two 316 00:17:52,000 --> 00:17:55,000 since we had assigned the value to student underscore copy. 317 00:17:55,000 --> 00:17:57,000 So here also we are getting Krish two. 318 00:17:57,000 --> 00:17:59,000 And this is a big problem right? 319 00:17:59,000 --> 00:18:02,000 So how do I make a separate copy. 320 00:18:02,000 --> 00:18:07,000 You know whenever I probably want to make a copy for this particular dictionary to an another variable 321 00:18:07,000 --> 00:18:13,000 in such a way that after that if I update this, the same update should not happen in your copy variable. 322 00:18:13,000 --> 00:18:17,000 So for that I will be showing you about shallow copy. 323 00:18:17,000 --> 00:18:23,000 Now in shallow copy, what we do is that let's say I go ahead and create my student copy one variable. 324 00:18:23,000 --> 00:18:26,000 I will go ahead and write student dot copy function. 325 00:18:26,000 --> 00:18:26,000 Okay. 326 00:18:26,000 --> 00:18:30,000 Now this copy function is responsible for doing the shallow copy over here. 327 00:18:30,000 --> 00:18:35,000 In short if you really want to understand this will basically allocate a different memory. 328 00:18:35,000 --> 00:18:40,000 It will take this variable and it will give the reference of this variable to an another memory, which 329 00:18:40,000 --> 00:18:43,000 will have that entire value that we really want to store. 330 00:18:44,000 --> 00:18:44,000 Okay. 331 00:18:44,000 --> 00:18:53,000 Now if I go ahead and print student underscore copy student underscore copy one okay. 332 00:18:53,000 --> 00:18:57,000 And if I go want to go ahead and print student. 333 00:18:57,000 --> 00:18:58,000 Right. 334 00:18:58,000 --> 00:19:01,000 And if I execute it now here you can see, okay, I'm having the same value. 335 00:19:01,000 --> 00:19:08,000 But now let me just update the student name, okay. 336 00:19:08,000 --> 00:19:13,000 If I go ahead and update the student name, let's say if I go ahead and write Chris three okay. 337 00:19:14,000 --> 00:19:19,000 Now if I go ahead and print both of them, will I get the same value of the name? 338 00:19:19,000 --> 00:19:20,000 The answer is no. 339 00:19:20,000 --> 00:19:25,000 See, I will execute this now in my student underscore copy one. 340 00:19:25,000 --> 00:19:29,000 I still have Chris two and student I have Chris three. 341 00:19:29,000 --> 00:19:29,000 Right. 342 00:19:29,000 --> 00:19:33,000 And why this was possible because of the shallow copy itself. 343 00:19:33,000 --> 00:19:33,000 Right. 344 00:19:33,000 --> 00:19:35,000 So just get an idea about shallow copy. 345 00:19:35,000 --> 00:19:42,000 Uh, shallow copy in turns, you know, provides a different memory location so that whenever we change 346 00:19:42,000 --> 00:19:45,000 one of the variable, it should not impact the other one. 347 00:19:45,000 --> 00:19:45,000 Okay. 348 00:19:45,000 --> 00:19:50,000 So just a smaller thing to understand over here because this will be important when you are doing the 349 00:19:50,000 --> 00:19:51,000 coding. 350 00:19:51,000 --> 00:19:58,000 Now let's go ahead and discuss about iterating over dictionaries. 351 00:19:58,000 --> 00:19:59,000 Okay. 352 00:19:59,000 --> 00:20:04,000 First thing you can use loops to iterate. 353 00:20:04,000 --> 00:20:11,000 Like how did we do in the in the in the case of list or in the case of tuples. 354 00:20:11,000 --> 00:20:14,000 So here also we are specifically. 355 00:20:15,000 --> 00:20:16,000 Okay I'll write. 356 00:20:16,000 --> 00:20:22,000 You can use okay loops to iterate. 357 00:20:23,000 --> 00:20:26,000 And we can iterate over dictionaries. 358 00:20:26,000 --> 00:20:28,000 And you know in dictionaries. 359 00:20:28,000 --> 00:20:34,000 Uh, if I probably talk about we have keys, we have values or we have items. 360 00:20:34,000 --> 00:20:38,000 Items basically means the combination of key and value pair, right. 361 00:20:38,000 --> 00:20:40,000 So let me just go ahead and show you the same example. 362 00:20:40,000 --> 00:20:43,000 Let's say that this is my student variable okay. 363 00:20:43,000 --> 00:20:47,000 And for this particular student I will go ahead and iterate through each and everything. 364 00:20:47,000 --> 00:20:53,000 So first of all I will try to show you iterating over keys okay. 365 00:20:53,000 --> 00:20:59,000 Now iterating over keys for keys in again we'll use a for loop and I will just go ahead and write student 366 00:20:59,000 --> 00:21:00,000 dot keys. 367 00:21:00,000 --> 00:21:04,000 When I write student dot keys, obviously you'll be able to see that I'll be getting the keys itself. 368 00:21:04,000 --> 00:21:08,000 If I go ahead and print the key, you'll be able to see. 369 00:21:09,000 --> 00:21:09,000 Oops. 370 00:21:10,000 --> 00:21:10,000 Uh, keys. 371 00:21:10,000 --> 00:21:11,000 Sorry. 372 00:21:11,000 --> 00:21:14,000 You'll be able to see name, age, and address. 373 00:21:14,000 --> 00:21:16,000 These are the keys that I have actually defined. 374 00:21:16,000 --> 00:21:28,000 Similarly, you can iterate iterate over values, and for that what you need to do again, copy the 375 00:21:28,000 --> 00:21:28,000 same thing. 376 00:21:29,000 --> 00:21:29,000 Right? 377 00:21:29,000 --> 00:21:32,000 Paste it over here instead of student dot keys. 378 00:21:32,000 --> 00:21:35,000 Now you go ahead and write student dot values. 379 00:21:36,000 --> 00:21:37,000 Okay. 380 00:21:37,000 --> 00:21:43,000 And once I go ahead and write it over here I can print it over here itself. 381 00:21:43,000 --> 00:21:46,000 And this is what you will be able to get a value Chris three. 382 00:21:46,000 --> 00:21:49,000 You'll be able to get 33 India. 383 00:21:49,000 --> 00:22:05,000 Okay, now if I want to iterate, iterate over key value pairs, then what we really need to do I will 384 00:22:05,000 --> 00:22:08,000 be using two variable in my for loop. 385 00:22:08,000 --> 00:22:15,000 One is key, comma value and student dot items. 386 00:22:16,000 --> 00:22:21,000 And now I will just go ahead and print by using an f string. 387 00:22:21,000 --> 00:22:22,000 Okay. 388 00:22:22,000 --> 00:22:25,000 So this is one way of formatting. 389 00:22:25,000 --> 00:22:28,000 Um in sprint formatting I can go ahead and write my key. 390 00:22:29,000 --> 00:22:30,000 Along with this. 391 00:22:30,000 --> 00:22:34,000 I can go ahead and write my value if I go ahead and see this. 392 00:22:34,000 --> 00:22:35,000 This is my age. 393 00:22:35,000 --> 00:22:37,000 Three age. 394 00:22:37,000 --> 00:22:37,000 Uh, sorry. 395 00:22:37,000 --> 00:22:39,000 Name Chris three, age 33. 396 00:22:39,000 --> 00:22:40,000 Address India. 397 00:22:41,000 --> 00:22:44,000 So you can also iterate over the key value pairs. 398 00:22:44,000 --> 00:22:49,000 And just by writing string dot items, you get that value in tuples right in list of tuples. 399 00:22:49,000 --> 00:22:54,000 So all these things you can basically work and you can basically iterate over the dictionaries. 400 00:22:54,000 --> 00:23:01,000 Now talking about the next one, uh, here we are going to go ahead with let me make some cells. 401 00:23:01,000 --> 00:23:01,000 Okay. 402 00:23:01,000 --> 00:23:07,000 So we are going to talk about nested dictionaries. 403 00:23:07,000 --> 00:23:07,000 Okay. 404 00:23:08,000 --> 00:23:09,000 Now nested dictionaries. 405 00:23:09,000 --> 00:23:12,000 A dictionary inside another dictionary okay. 406 00:23:12,000 --> 00:23:15,000 And usually if I talk about databases MongoDB. 407 00:23:15,000 --> 00:23:16,000 Right. 408 00:23:16,000 --> 00:23:17,000 NoSQL database over there. 409 00:23:17,000 --> 00:23:19,000 Everything is stored in key value pair. 410 00:23:19,000 --> 00:23:23,000 Whenever we say key value pair later on we can read that convert that into a dictionary. 411 00:23:23,000 --> 00:23:26,000 And I may have any number of records in the MongoDB database. 412 00:23:26,000 --> 00:23:27,000 Right. 413 00:23:27,000 --> 00:23:29,000 So let me just go ahead and do one thing. 414 00:23:29,000 --> 00:23:33,000 Let me go ahead and write students, and let me just show you how you can create key value pairs. 415 00:23:33,000 --> 00:23:34,000 Okay. 416 00:23:35,000 --> 00:23:37,000 So let's say this is my first key. 417 00:23:37,000 --> 00:23:39,000 That is nothing but student one. 418 00:23:39,000 --> 00:23:42,000 And I will just go ahead and write my key value pair here. 419 00:23:42,000 --> 00:23:47,000 The first thing I will go and see name name is let's say Krish. 420 00:23:48,000 --> 00:23:50,000 Uh, age is. 421 00:23:50,000 --> 00:23:54,000 Let's say colon 32. 422 00:23:54,000 --> 00:23:55,000 Okay. 423 00:23:55,000 --> 00:23:57,000 And, uh, age 32. 424 00:23:57,000 --> 00:24:00,000 And here I am specifically creating this. 425 00:24:00,000 --> 00:24:00,000 Right. 426 00:24:00,000 --> 00:24:01,000 Sorry. 427 00:24:01,000 --> 00:24:05,000 It should be colon not equal to colon 32. 428 00:24:05,000 --> 00:24:05,000 Okay. 429 00:24:06,000 --> 00:24:07,000 This is my first record. 430 00:24:07,000 --> 00:24:08,000 Huh. 431 00:24:08,000 --> 00:24:11,000 Now let me go ahead and create my second record. 432 00:24:11,000 --> 00:24:17,000 Let's say I may have student two data And now with respect to this particular student two data, I may 433 00:24:17,000 --> 00:24:18,000 have name. 434 00:24:19,000 --> 00:24:32,000 Name is nothing but let's say fresh or I'll just say, um, Spider-Man or Peter Parker or anyone. 435 00:24:32,000 --> 00:24:32,000 Right? 436 00:24:32,000 --> 00:24:33,000 So Peter. 437 00:24:33,000 --> 00:24:34,000 Right. 438 00:24:35,000 --> 00:24:38,000 Age is nothing but let's say 35. 439 00:24:38,000 --> 00:24:39,000 Right. 440 00:24:39,000 --> 00:24:41,000 So here you can see key value pairs. 441 00:24:41,000 --> 00:24:42,000 Right. 442 00:24:42,000 --> 00:24:43,000 And this is nothing. 443 00:24:43,000 --> 00:24:45,000 But this is basically a nested dictionary. 444 00:24:45,000 --> 00:24:53,000 Right now if I go ahead and print students you will be able to see that hey it looks like a dictionary. 445 00:24:53,000 --> 00:24:54,000 Key value pairs. 446 00:24:54,000 --> 00:24:56,000 Again it can have nested key value pairs. 447 00:24:56,000 --> 00:24:57,000 Right. 448 00:24:57,000 --> 00:25:04,000 But these are just like a kind of records like how we uploaded in MongoDB or in any other NoSQL database, 449 00:25:04,000 --> 00:25:06,000 NoSQL databases right now. 450 00:25:06,000 --> 00:25:08,000 How do we access this? 451 00:25:08,000 --> 00:25:16,000 Nested dictionaries access nested dictionaries, dictionaries, elements. 452 00:25:16,000 --> 00:25:17,000 Okay. 453 00:25:17,000 --> 00:25:22,000 So I will just go ahead and print right students. 454 00:25:24,000 --> 00:25:29,000 And here I'm going to use, let's say I want to read The Age of Peter Parker. 455 00:25:29,000 --> 00:25:30,000 Then how do I write? 456 00:25:30,000 --> 00:25:31,000 So I will just go ahead and write. 457 00:25:31,000 --> 00:25:32,000 Student uh. 458 00:25:32,000 --> 00:25:34,000 Student two okay. 459 00:25:34,000 --> 00:25:39,000 And the next bracket will be specifically name okay or name or age. 460 00:25:39,000 --> 00:25:43,000 I can also get name if I want to print, I can print name. 461 00:25:43,000 --> 00:25:48,000 Let's say if I go ahead and print this entire information along with age, here I will be getting age 462 00:25:48,000 --> 00:25:49,000 or name of Peter Parker. 463 00:25:49,000 --> 00:25:52,000 And and here I'll be getting the age right. 464 00:25:52,000 --> 00:25:55,000 So if I go and see Peter and 35 right. 465 00:25:55,000 --> 00:26:00,000 So here with respect to the nested dictionaries, also like how we read in in nested list. 466 00:26:00,000 --> 00:26:02,000 Similarly we can go ahead and do that here. 467 00:26:02,000 --> 00:26:06,000 The main thing is that we only have to call the key names, and automatically you'll be able to get 468 00:26:06,000 --> 00:26:08,000 the value names right. 469 00:26:08,000 --> 00:26:11,000 So this is one amazing way of playing with nested dictionaries. 470 00:26:11,000 --> 00:26:12,000 Okay. 471 00:26:12,000 --> 00:26:15,000 Now uh, again, you can try multiple example. 472 00:26:15,000 --> 00:26:19,000 You can create your own nested dictionaries, any level of nested dictionaries. 473 00:26:20,000 --> 00:26:22,000 Uh, there is no limit as such inside name. 474 00:26:22,000 --> 00:26:25,000 Also, you can again go ahead and create another nested dictionary if you want. 475 00:26:25,000 --> 00:26:26,000 Okay. 476 00:26:26,000 --> 00:26:34,000 Now let me just go ahead and show you one more thing iterating over nested dictionaries. 477 00:26:34,000 --> 00:26:34,000 Okay. 478 00:26:35,000 --> 00:26:38,000 Now for let's say I will go ahead and write for student underscore ID. 479 00:26:39,000 --> 00:26:39,000 Okay. 480 00:26:39,000 --> 00:26:42,000 Since I require ID and information. 481 00:26:42,000 --> 00:26:44,000 So let's say I will go ahead and write like this. 482 00:26:44,000 --> 00:26:46,000 Just see this okay. 483 00:26:46,000 --> 00:26:53,000 Student underscore info okay I will consider this as ID and this as the entire info okay. 484 00:26:53,000 --> 00:27:01,000 And if I go ahead and write students students students okay Okay. 485 00:27:01,000 --> 00:27:03,000 Dot items. 486 00:27:04,000 --> 00:27:09,000 So what will student dot item give me if I go ahead and execute a code over here? 487 00:27:09,000 --> 00:27:14,000 What will students dot items items give me. 488 00:27:14,000 --> 00:27:17,000 It will give me dictionary in the key value pairs. 489 00:27:17,000 --> 00:27:18,000 Right. 490 00:27:18,000 --> 00:27:23,000 Like student one will be one key and this will be a entire value right inside this. 491 00:27:23,000 --> 00:27:27,000 This can be a key and this can be a value, but it will be giving you in this particular format. 492 00:27:27,000 --> 00:27:32,000 Now if I iterate over this nested dictionary, this I will consider as my id, and this will I'll consider 493 00:27:32,000 --> 00:27:33,000 as my value. 494 00:27:33,000 --> 00:27:34,000 Right. 495 00:27:34,000 --> 00:27:38,000 So that is the reason I've written from student underscore ID and student underscore info. 496 00:27:38,000 --> 00:27:38,000 Right. 497 00:27:38,000 --> 00:27:40,000 So this can be a temporary variable. 498 00:27:40,000 --> 00:27:43,000 Right now I will just go ahead and print okay. 499 00:27:43,000 --> 00:27:46,000 So one print I will just use an F string. 500 00:27:46,000 --> 00:27:51,000 And inside this f string let me first of all go ahead and display my student underscore ID okay. 501 00:27:51,000 --> 00:27:56,000 And this will basically be my student underscore info. 502 00:27:56,000 --> 00:28:04,000 Right now I may want a scenario wherein I traverse through or I iterate over all the elements that are 503 00:28:04,000 --> 00:28:05,000 inside this. 504 00:28:05,000 --> 00:28:05,000 Right. 505 00:28:05,000 --> 00:28:06,000 So let me do that. 506 00:28:06,000 --> 00:28:10,000 So I will go ahead and write for key comma value okay. 507 00:28:10,000 --> 00:28:16,000 In student underscore info right I need to iterate through this. 508 00:28:16,000 --> 00:28:19,000 And this all information are present inside student underscore info. 509 00:28:19,000 --> 00:28:22,000 Now inside this also I will be able to find out keys and values. 510 00:28:22,000 --> 00:28:27,000 So I will go ahead and print F again my key. 511 00:28:28,000 --> 00:28:35,000 And this will be nothing but it will be colon again my value right now let's go ahead and see. 512 00:28:35,000 --> 00:28:42,000 Uh so there is an error for key comma value in student underscore info dot items. 513 00:28:42,000 --> 00:28:47,000 I, I missed out dot items because I am not getting too many information out of it. 514 00:28:47,000 --> 00:28:49,000 So see how it is printing this first information. 515 00:28:49,000 --> 00:28:51,000 This is my student. 516 00:28:51,000 --> 00:28:52,000 All the information is over here. 517 00:28:52,000 --> 00:28:56,000 Then I took this info and I iterated through every key and values. 518 00:28:56,000 --> 00:28:57,000 Right? 519 00:28:57,000 --> 00:28:58,000 So name is equal to crush. 520 00:28:58,000 --> 00:28:59,000 Age is equal to 32. 521 00:28:59,000 --> 00:29:01,000 Then again it went to the for loop. 522 00:29:01,000 --> 00:29:07,000 It found out the another student ID that is student two with this name and now it is printing name is 523 00:29:07,000 --> 00:29:08,000 equal to Peter and age is equal to five. 524 00:29:09,000 --> 00:29:13,000 So this is how you iterate over nested dictionaries. 525 00:29:13,000 --> 00:29:16,000 And you can play with different different elements as you want. 526 00:29:16,000 --> 00:29:16,000 Okay. 527 00:29:17,000 --> 00:29:22,000 So again Ellen any level of nesting let it be right. 528 00:29:22,000 --> 00:29:23,000 You can iterate through each and everything. 529 00:29:23,000 --> 00:29:27,000 And just by using dot items you can get the key value pairs. 530 00:29:27,000 --> 00:29:35,000 Okay, now let me just go ahead and talk about dictionary comprehension. 531 00:29:35,000 --> 00:29:39,000 Like how discussed about nested list uh list comprehension. 532 00:29:39,000 --> 00:29:43,000 Similarly we'll discuss about uh dictionary comprehension okay. 533 00:29:43,000 --> 00:29:45,000 Now dictionary comprehension. 534 00:29:45,000 --> 00:29:46,000 How does it work. 535 00:29:46,000 --> 00:29:55,000 Uh, and uh, let's say that I want to just print what is the square of a specific number between 1 536 00:29:55,000 --> 00:29:56,000 to 10. 537 00:29:56,000 --> 00:29:56,000 Okay. 538 00:29:56,000 --> 00:29:58,000 So let me just go ahead and create a variable. 539 00:29:58,000 --> 00:30:00,000 Squares is equal to. 540 00:30:00,000 --> 00:30:03,000 And again what is the mechanism in list comprehension. 541 00:30:03,000 --> 00:30:05,000 We basically write like this right. 542 00:30:05,000 --> 00:30:10,000 In dictionary comprehension we use uh angular braces right. 543 00:30:10,000 --> 00:30:13,000 So first thing first always remember we need to write. 544 00:30:13,000 --> 00:30:14,000 You can write a for loop. 545 00:30:14,000 --> 00:30:15,000 You can write any condition over here. 546 00:30:15,000 --> 00:30:19,000 So let me go ahead and write for x in range of five okay. 547 00:30:20,000 --> 00:30:25,000 So I'm iterating between 0 to 5 and what I want I want to display something like this x is equal to 548 00:30:25,000 --> 00:30:30,000 x square okay I'm basically squaring each and every number. 549 00:30:30,000 --> 00:30:33,000 And that is what is my x value. 550 00:30:33,000 --> 00:30:36,000 And this way it will probably display me. 551 00:30:36,000 --> 00:30:38,000 And this is the way how key and value pairs displays. 552 00:30:38,000 --> 00:30:39,000 Right. 553 00:30:39,000 --> 00:30:39,000 right? 554 00:30:39,000 --> 00:30:40,000 So this is my key. 555 00:30:40,000 --> 00:30:41,000 This will be the value. 556 00:30:41,000 --> 00:30:43,000 This will be my key. 557 00:30:43,000 --> 00:30:45,000 This will be the value as we keep on iterating. 558 00:30:45,000 --> 00:30:52,000 So if I just go ahead and execute this print squares again you can one assignment I definitely like 559 00:30:52,000 --> 00:30:53,000 to give you. 560 00:30:53,000 --> 00:30:57,000 Just go ahead and write this entire thing with a simple for loop okay. 561 00:30:57,000 --> 00:31:01,000 And then you try to convert this into a dictionary right a dictionary comprehension. 562 00:31:01,000 --> 00:31:04,000 So here you can see now I'm able to get a key value pair. 563 00:31:04,000 --> 00:31:05,000 So this is my zero is my key. 564 00:31:05,000 --> 00:31:06,000 Zero is the value. 565 00:31:06,000 --> 00:31:07,000 One is the key one is the value. 566 00:31:07,000 --> 00:31:09,000 Two is the key, four is the value. 567 00:31:09,000 --> 00:31:11,000 And we are doing the squaring of it right. 568 00:31:11,000 --> 00:31:12,000 Squaring off each and every number. 569 00:31:14,000 --> 00:31:20,000 Now let's say I want to probably go ahead and just find out the squares off only even number. 570 00:31:20,000 --> 00:31:22,000 So here I will also show you by writing conditions. 571 00:31:22,000 --> 00:31:27,000 So let me just go ahead and write conditional dictionary. 572 00:31:29,000 --> 00:31:31,000 Comprehension. 573 00:31:32,000 --> 00:31:33,000 Okay. 574 00:31:33,000 --> 00:31:34,000 Comprehension. 575 00:31:35,000 --> 00:31:41,000 Now the best way over here is that I will go ahead and create even variable. 576 00:31:41,000 --> 00:31:48,000 Now first of all for x in range of ten let me just go ahead and take ten variables. 577 00:31:48,000 --> 00:31:53,000 Okay I know what I need to display x square okay. 578 00:31:53,000 --> 00:31:55,000 But I will write one more condition. 579 00:31:55,000 --> 00:32:04,000 If if x modulus two is double equal to zero I will go ahead and print my events okay. 580 00:32:04,000 --> 00:32:06,000 Now let me just go ahead and execute it. 581 00:32:06,000 --> 00:32:10,000 So this is zero column zero two colon four four. 582 00:32:10,000 --> 00:32:11,000 Column 16 six. 583 00:32:11,000 --> 00:32:12,000 Colon 36 eight. 584 00:32:12,000 --> 00:32:13,000 Colon 64. 585 00:32:13,000 --> 00:32:14,000 Right. 586 00:32:14,000 --> 00:32:18,000 So this is in short giving me the square of only even numbers. 587 00:32:18,000 --> 00:32:22,000 Right now these are some of the examples. 588 00:32:22,000 --> 00:32:23,000 Again dictionary comprehension. 589 00:32:23,000 --> 00:32:26,000 You can like how do you execute with respect to list. 590 00:32:26,000 --> 00:32:30,000 Similarly you can also do it with respect to uh ordinaries only. 591 00:32:30,000 --> 00:32:35,000 The thing is that you need to have the output over here in the form of key value pairs. 592 00:32:35,000 --> 00:32:36,000 Okay. 593 00:32:36,000 --> 00:32:38,000 So this was one of the most amazing thing. 594 00:32:38,000 --> 00:32:39,000 Okay. 595 00:32:39,000 --> 00:32:46,000 Let me just show you some of the practical examples that may be beneficial for understanding, um, 596 00:32:46,000 --> 00:32:48,000 some more practical examples. 597 00:32:48,000 --> 00:32:54,000 And in the next video I will also talk about some of the amazing use cases where all this list, dictionaries 598 00:32:54,000 --> 00:32:55,000 or dictionaries will be used. 599 00:32:55,000 --> 00:32:56,000 Okay. 600 00:32:56,000 --> 00:32:59,000 So practical examples okay. 601 00:32:59,000 --> 00:33:04,000 Now with respect to this practical example I will give you a task. 602 00:33:04,000 --> 00:33:06,000 Use a dictionary. 603 00:33:08,000 --> 00:33:08,000 Okay. 604 00:33:09,000 --> 00:33:18,000 Use a dictionary to count the frequency of elements in list okay. 605 00:33:19,000 --> 00:33:21,000 Now we'll go ahead and see this. 606 00:33:21,000 --> 00:33:23,000 Let's say I have numbers. 607 00:33:23,000 --> 00:33:28,000 Numbers is nothing, but it is in the list format one comma two comma two. 608 00:33:29,000 --> 00:33:36,000 comma, three comma, three comma, three comma, four comma four comma four comma four. 609 00:33:36,000 --> 00:33:36,000 Okay. 610 00:33:36,000 --> 00:33:37,000 So these are my numbers. 611 00:33:37,000 --> 00:33:42,000 Now you need to write a code using dictionary to count the frequency of every element in the list. 612 00:33:42,000 --> 00:33:46,000 Like one is present one time, two is present two times something like this. 613 00:33:46,000 --> 00:33:48,000 So I will go ahead and create. 614 00:33:48,000 --> 00:33:49,000 First of all you try it out. 615 00:33:49,000 --> 00:33:50,000 Okay. 616 00:33:50,000 --> 00:33:56,000 Just pause for five, five, at least five minutes and just try to write whatever is possible by you 617 00:33:56,000 --> 00:33:58,000 and then go ahead and see the solution. 618 00:33:58,000 --> 00:33:58,000 Okay. 619 00:33:58,000 --> 00:34:02,000 Now let me just go ahead and create a frequency empty variable. 620 00:34:02,000 --> 00:34:08,000 Then I will go ahead and write for number in numbers. 621 00:34:08,000 --> 00:34:09,000 Okay. 622 00:34:09,000 --> 00:34:12,000 First of all I will iterate through each and every number. 623 00:34:12,000 --> 00:34:16,000 Then I will go ahead and write if number in frequency. 624 00:34:17,000 --> 00:34:17,000 Okay. 625 00:34:17,000 --> 00:34:20,000 If the number is basically present in the frequency, then it is fine. 626 00:34:21,000 --> 00:34:28,000 Then what we do, we basically take that frequency of number and we keep on incrementing it. 627 00:34:28,000 --> 00:34:28,000 Right. 628 00:34:28,000 --> 00:34:29,000 Plus is equal to one. 629 00:34:30,000 --> 00:34:35,000 Now what exactly this is basically doing this is with respect to the key and with respect to that particular 630 00:34:35,000 --> 00:34:39,000 key I need to just increment keep on incrementing the value saying that hey it is present one time two 631 00:34:39,000 --> 00:34:43,000 time three time Like when two times basically comes, right? 632 00:34:43,000 --> 00:34:46,000 So first time it will be zero and then it will go to one, two, three like that okay. 633 00:34:47,000 --> 00:34:55,000 Else if it is coming for the first time then we should basically assign that value to one, right. 634 00:34:56,000 --> 00:34:57,000 Otherwise it will keep on incrementing. 635 00:34:57,000 --> 00:34:59,000 So number is equal to one. 636 00:34:59,000 --> 00:35:02,000 Now let me just go ahead and print the frequency. 637 00:35:02,000 --> 00:35:07,000 So here you'll be able to understand how many number of times one is present, two is present and three 638 00:35:07,000 --> 00:35:07,000 is present. 639 00:35:07,000 --> 00:35:08,000 Just see this code. 640 00:35:08,000 --> 00:35:10,000 Observe this code okay. 641 00:35:10,000 --> 00:35:13,000 If I go ahead and execute it now here you can see numbers. 642 00:35:13,000 --> 00:35:14,000 It is iterating. 643 00:35:14,000 --> 00:35:16,000 If number is in the frequency initially it is not present. 644 00:35:16,000 --> 00:35:18,000 So what it will do it will go over here. 645 00:35:18,000 --> 00:35:21,000 Take this number and it will assign the value one. 646 00:35:21,000 --> 00:35:23,000 Then it will go again back to the next number. 647 00:35:23,000 --> 00:35:26,000 Two is present number is not present in the frequency. 648 00:35:26,000 --> 00:35:28,000 It will again go back to the else loop. 649 00:35:28,000 --> 00:35:29,000 And again it will update one. 650 00:35:29,000 --> 00:35:32,000 Then again it will go back okay. 651 00:35:32,000 --> 00:35:33,000 Then the next number is two. 652 00:35:33,000 --> 00:35:35,000 This time it is present in the frequency. 653 00:35:35,000 --> 00:35:36,000 So it will go inside. 654 00:35:36,000 --> 00:35:41,000 This frequency of two is equal to plus is equal to one right plus equal to one. 655 00:35:41,000 --> 00:35:43,000 So that basically we are just going to increment one with one. 656 00:35:43,000 --> 00:35:44,000 So it will become two. 657 00:35:44,000 --> 00:35:46,000 So how many number of times two is present. 658 00:35:46,000 --> 00:35:48,000 Only that much will be remaining three. 659 00:35:48,000 --> 00:35:52,000 It will increment till three four it will increment till four because there are four number of fours. 660 00:35:52,000 --> 00:35:53,000 Okay. 661 00:35:53,000 --> 00:35:53,000 okay. 662 00:35:53,000 --> 00:35:56,000 So this is how you specifically get one amazing thing okay. 663 00:35:57,000 --> 00:36:00,000 Now let me just show you another one example. 664 00:36:00,000 --> 00:36:02,000 And this is probably we have not discussed. 665 00:36:02,000 --> 00:36:06,000 Also let's go ahead and merge two dictionaries into one okay. 666 00:36:06,000 --> 00:36:10,000 There may be scenario that I may have two dictionaries and I really want to merge them into one. 667 00:36:10,000 --> 00:36:11,000 Okay. 668 00:36:11,000 --> 00:36:15,000 This is one kind of hack that I really want to show it to you. 669 00:36:15,000 --> 00:36:20,000 So dictionary one and this is what we will understand when we understand about functions, because there 670 00:36:20,000 --> 00:36:25,000 is one very key important parameter which is called as positional argument and keyword argument. 671 00:36:25,000 --> 00:36:25,000 Okay. 672 00:36:26,000 --> 00:36:29,000 Uh, why we use Asterix mask and all. 673 00:36:29,000 --> 00:36:31,000 I'll just discuss when we discuss about the function. 674 00:36:31,000 --> 00:36:37,000 So now let me say that hey, there is my dictionary elements over here a is equal to one and this B 675 00:36:37,000 --> 00:36:40,000 is nothing but equal to two okay. 676 00:36:40,000 --> 00:36:42,000 Similarly I may have a different dictionary. 677 00:36:42,000 --> 00:36:53,000 The second dictionary here B colon three and c is colon four. 678 00:36:54,000 --> 00:36:54,000 Okay. 679 00:36:54,000 --> 00:37:01,000 Now if I go ahead and write merge dictionary okay. 680 00:37:02,000 --> 00:37:07,000 Now see if I go ahead and try to merge this dictionary. 681 00:37:07,000 --> 00:37:09,000 I will use two amazing things over here. 682 00:37:09,000 --> 00:37:11,000 One is asterisk. 683 00:37:11,000 --> 00:37:12,000 Asterisk. 684 00:37:12,000 --> 00:37:13,000 Dictionary one okay. 685 00:37:13,000 --> 00:37:17,000 Comma asterisk asterisk dictionary two. 686 00:37:17,000 --> 00:37:24,000 Now, the best thing about this asterisk is that any number of a number of key value pairs. 687 00:37:24,000 --> 00:37:24,000 Right. 688 00:37:24,000 --> 00:37:29,000 If I'm giving two double asterisk any number of key value pairs, that is probably going to consider 689 00:37:29,000 --> 00:37:30,000 come. 690 00:37:30,000 --> 00:37:34,000 It is just going to take that as a key value pair, and it is just going to append it inside this particular 691 00:37:34,000 --> 00:37:35,000 dictionary okay. 692 00:37:36,000 --> 00:37:38,000 This is basically called as a keyword argument okay. 693 00:37:38,000 --> 00:37:43,000 And over here you can see in dictionary one and dictionary two both are keywords argument okay. 694 00:37:43,000 --> 00:37:47,000 So keywords argument basically means any value that is present in the form of key value pairs. 695 00:37:47,000 --> 00:37:48,000 Okay. 696 00:37:48,000 --> 00:37:53,000 Now if I go ahead and print this merge dictionary and we'll discuss more about that in functions okay. 697 00:37:54,000 --> 00:37:57,000 So here you can see that it has merged very much easily okay. 698 00:37:58,000 --> 00:38:01,000 So I hope you got an idea about dictionaries. 699 00:38:02,000 --> 00:38:06,000 We have discussed so many different lines of code I have written over here in front of you, and almost 700 00:38:06,000 --> 00:38:08,000 each and every topics with some examples. 701 00:38:08,000 --> 00:38:13,000 And all I have actually explained, explained in a way that you should be able to understand a very 702 00:38:13,000 --> 00:38:14,000 lame language. 703 00:38:14,000 --> 00:38:16,000 So I hope you like this particular video. 704 00:38:16,000 --> 00:38:17,000 This was it for my side. 705 00:38:17,000 --> 00:38:18,000 I will see you all in the next video. 706 00:38:18,000 --> 00:38:18,000 Thank you. 707 00:38:18,000 --> 00:38:18,000 Take care.