1 00:00:00,000 --> 00:00:00,000 Hello guys. 2 00:00:00,000 --> 00:00:03,000 So we are going to continue the discussion with respect to Python. 3 00:00:03,000 --> 00:00:05,000 And in this video we are going to discuss about variables. 4 00:00:05,000 --> 00:00:06,000 Okay. 5 00:00:06,000 --> 00:00:07,000 Now what exactly is variables. 6 00:00:07,000 --> 00:00:10,000 And uh here I have also given the entire video outline. 7 00:00:10,000 --> 00:00:15,000 So we will first of all introduce like uh the topic is introduction to variables. 8 00:00:15,000 --> 00:00:18,000 Then we'll be seeing how we can declare and assign variables. 9 00:00:18,000 --> 00:00:20,000 Then we'll talk about the naming convention. 10 00:00:20,000 --> 00:00:21,000 Then we'll understand variable type. 11 00:00:21,000 --> 00:00:24,000 We'll see type checking and conversion dynamic typing. 12 00:00:24,000 --> 00:00:28,000 And finally we'll be seeing a lot of practical examples and common errors okay. 13 00:00:28,000 --> 00:00:31,000 So all these things will be specifically covered in this video okay. 14 00:00:31,000 --> 00:00:34,000 Now first of all, as usual let's go with the definition. 15 00:00:34,000 --> 00:00:39,000 So variables are fundamental elements in programming used to store data that can be referenced and manipulated 16 00:00:39,000 --> 00:00:41,000 in a program in Python. 17 00:00:41,000 --> 00:00:46,000 Variables are created when you assign a value to them, and they do not need explicit declaration to 18 00:00:46,000 --> 00:00:48,000 reserve memory space. 19 00:00:48,000 --> 00:00:52,000 The declaration happens automatically when you assign a value to a variable. 20 00:00:52,000 --> 00:00:52,000 Okay. 21 00:00:52,000 --> 00:00:57,000 So, uh, the best way to give you an example is that let's say if I define a is equal to 100. 22 00:00:57,000 --> 00:00:59,000 So this basically becomes the variable. 23 00:00:59,000 --> 00:01:04,000 And always remember guys, whenever you start a new notebook file always make sure to select the kernel 24 00:01:04,000 --> 00:01:04,000 okay. 25 00:01:04,000 --> 00:01:06,000 Now if I'm going to write a is equal to 100. 26 00:01:06,000 --> 00:01:11,000 This basically means that I've created a variable a and I've assigned a value to 100 okay. 27 00:01:11,000 --> 00:01:16,000 Now uh, obviously in my previous video I've also defined some basic variables and all and I've assigned 28 00:01:16,000 --> 00:01:21,000 some values, let's say string, numerical, uh, integers, floating point, anything, any values 29 00:01:21,000 --> 00:01:22,000 you can basically assign. 30 00:01:23,000 --> 00:01:24,000 Uh, we'll be learning more about it. 31 00:01:24,000 --> 00:01:34,000 Uh, so first of all, let's go ahead and understanding about declaring, declaring and assigning variables. 32 00:01:34,000 --> 00:01:34,000 Okay. 33 00:01:35,000 --> 00:01:40,000 So here, uh, you'll be able to see that, uh, let's say I'm going to define age is equal to 32. 34 00:01:40,000 --> 00:01:45,000 I'm going to probably define height is equal to six feet or 6.1. 35 00:01:45,000 --> 00:01:47,000 That is specifically my height. 36 00:01:47,000 --> 00:01:48,000 So I'm writing it down. 37 00:01:48,000 --> 00:01:49,000 Height is equal to 6.1. 38 00:01:49,000 --> 00:01:52,000 Then let's say name is equal to my name. 39 00:01:52,000 --> 00:01:53,000 I will go ahead and define crush. 40 00:01:54,000 --> 00:01:58,000 Uh, and then here you can also see that I can also define a boolean variable. 41 00:01:58,000 --> 00:02:02,000 Let's say I will go ahead and define is underscore student okay. 42 00:02:02,000 --> 00:02:04,000 I will also talk about naming convention. 43 00:02:04,000 --> 00:02:07,000 Uh what is the best naming convention of defining a variable. 44 00:02:07,000 --> 00:02:08,000 What are the good practices. 45 00:02:08,000 --> 00:02:09,000 Everything I'll be discussing about. 46 00:02:09,000 --> 00:02:12,000 So let's say I'm going to define a boolean variable as true right. 47 00:02:12,000 --> 00:02:15,000 We'll learn more about the specific data types in my next video. 48 00:02:15,000 --> 00:02:17,000 But here I'm just giving you an example okay. 49 00:02:17,000 --> 00:02:19,000 So h is equal to 32. 50 00:02:19,000 --> 00:02:19,000 This this is there. 51 00:02:19,000 --> 00:02:21,000 And I have actually written it right now. 52 00:02:21,000 --> 00:02:23,000 Let me quickly go ahead and print it. 53 00:02:23,000 --> 00:02:26,000 And this is how we assign a variable right. 54 00:02:26,000 --> 00:02:28,000 We are declaring a variable and we signing some values. 55 00:02:28,000 --> 00:02:29,000 Right. 56 00:02:29,000 --> 00:02:34,000 So now let me just go ahead and print printing the variables. 57 00:02:34,000 --> 00:02:34,000 Right. 58 00:02:34,000 --> 00:02:36,000 So here you can see. 59 00:02:36,000 --> 00:02:39,000 So now first of all I'm going to print age right. 60 00:02:39,000 --> 00:02:45,000 And this is where I will also show you how you can use uh different print, how you can uh, display 61 00:02:45,000 --> 00:02:46,000 in your console in a different way. 62 00:02:46,000 --> 00:02:48,000 So first of all, let's say I want to print age. 63 00:02:48,000 --> 00:02:53,000 So age colon let's say I want to assign this age colon with some value over here. 64 00:02:53,000 --> 00:02:55,000 So I will go ahead and define my variable h right. 65 00:02:55,000 --> 00:03:01,000 Similarly, if I go ahead and show you the next print statement here, I'm going to basically write 66 00:03:01,000 --> 00:03:02,000 height okay. 67 00:03:02,000 --> 00:03:06,000 And with respect to this particular height I am going to define another variable. 68 00:03:06,000 --> 00:03:08,000 Let's say this will basically be my height. 69 00:03:08,000 --> 00:03:12,000 Another next thing that I'm going to print over here is my name. 70 00:03:12,000 --> 00:03:17,000 And here you can probably see that I'm going to basically define my name. 71 00:03:17,000 --> 00:03:19,000 And let me just go ahead and write comma. 72 00:03:19,000 --> 00:03:20,000 And this will basically be my name. 73 00:03:20,000 --> 00:03:21,000 Right. 74 00:03:21,000 --> 00:03:25,000 So if I want to define all these things you here, you can see I'm displaying age is equal to 32. 75 00:03:25,000 --> 00:03:26,000 Height is equal to 6.1. 76 00:03:26,000 --> 00:03:28,000 Name is equal to crush. 77 00:03:28,000 --> 00:03:32,000 That basically means see, when I'm printing I can also call this particular variable that I have actually 78 00:03:32,000 --> 00:03:32,000 defined. 79 00:03:32,000 --> 00:03:33,000 Okay. 80 00:03:33,000 --> 00:03:35,000 So these are some of the ways. 81 00:03:35,000 --> 00:03:40,000 Again we will be discussing about more different boolean type more different data types as we go ahead. 82 00:03:40,000 --> 00:03:43,000 And that is how we declare different different variables. 83 00:03:43,000 --> 00:03:46,000 But just a basic idea for you with respect to the variable declaration. 84 00:03:47,000 --> 00:03:47,000 Okay. 85 00:03:47,000 --> 00:03:51,000 Now coming to the next one, which is basically called as naming convention. 86 00:03:51,000 --> 00:03:52,000 And this is the most important one. 87 00:03:52,000 --> 00:03:55,000 Like how should we name a variable. 88 00:03:55,000 --> 00:03:55,000 Right. 89 00:03:56,000 --> 00:03:58,000 Then for this you really need to know about the naming convention. 90 00:03:59,000 --> 00:04:05,000 Some of the important points that I would like to mention over here, let's say uh, variables, uh, 91 00:04:05,000 --> 00:04:06,000 name. 92 00:04:06,000 --> 00:04:06,000 Right. 93 00:04:06,000 --> 00:04:14,000 The variable name that we define right should be should be descriptive. 94 00:04:15,000 --> 00:04:15,000 Okay. 95 00:04:15,000 --> 00:04:16,000 Then. 96 00:04:16,000 --> 00:04:24,000 Uh, the second point that I would like to mention, they must always start with a letter. 97 00:04:24,000 --> 00:04:24,000 Okay. 98 00:04:24,000 --> 00:04:26,000 So this is the second condition. 99 00:04:26,000 --> 00:04:29,000 Or it can also start with an underscore. 100 00:04:29,000 --> 00:04:29,000 Okay. 101 00:04:29,000 --> 00:04:33,000 Underscore like underscore uh this kind of underscore mark. 102 00:04:33,000 --> 00:04:33,000 Right. 103 00:04:33,000 --> 00:04:42,000 And uh it can contain letters numbers and underscore in between. 104 00:04:42,000 --> 00:04:43,000 Right. 105 00:04:43,000 --> 00:04:44,000 In between. 106 00:04:44,000 --> 00:04:49,000 But always understand they must always start with a letter or underscore. 107 00:04:49,000 --> 00:04:52,000 And it can contain letters, numbers and underscores. 108 00:04:52,000 --> 00:04:52,000 Okay. 109 00:04:52,000 --> 00:04:54,000 Within inside that okay. 110 00:04:55,000 --> 00:04:57,000 And uh, one more thing. 111 00:04:57,000 --> 00:04:59,000 Very important point, which I've already mentioned. 112 00:04:59,000 --> 00:05:04,000 Variables names are case sensitive. 113 00:05:05,000 --> 00:05:05,000 Okay. 114 00:05:05,000 --> 00:05:06,000 This also I have defined it. 115 00:05:06,000 --> 00:05:11,000 So these are some of the naming important naming convention with respect to the variables okay. 116 00:05:11,000 --> 00:05:13,000 Now let's see some kind of example over here. 117 00:05:13,000 --> 00:05:17,000 So first of all I will just go ahead and write some valid variable name. 118 00:05:17,000 --> 00:05:17,000 Okay. 119 00:05:17,000 --> 00:05:20,000 So valid variable names. 120 00:05:20,000 --> 00:05:26,000 So first valid variable name I'm going to define it as first underscore name is equal to crush okay. 121 00:05:26,000 --> 00:05:30,000 Uh last underscore name is equal to Nick. 122 00:05:30,000 --> 00:05:30,000 Right. 123 00:05:30,000 --> 00:05:34,000 So is this a good way of writing a variable. 124 00:05:34,000 --> 00:05:34,000 Yes. 125 00:05:34,000 --> 00:05:35,000 Does it start with a letter. 126 00:05:35,000 --> 00:05:36,000 Yes. 127 00:05:36,000 --> 00:05:37,000 It starts with a letter. 128 00:05:37,000 --> 00:05:41,000 Does can it contain letter number or numbers or underscores? 129 00:05:41,000 --> 00:05:42,000 Yes, it can contain. 130 00:05:42,000 --> 00:05:45,000 So here you can see I am having letters or underscore. 131 00:05:45,000 --> 00:05:49,000 I can also put numbers in between but not in the starting right. 132 00:05:49,000 --> 00:05:51,000 So this is a good way of defining a variable. 133 00:05:51,000 --> 00:05:52,000 Okay. 134 00:05:52,000 --> 00:05:55,000 So here uh this absolutely works fine. 135 00:05:55,000 --> 00:06:02,000 Let me say show you some invalid variable name invalid variable names okay. 136 00:06:02,000 --> 00:06:05,000 So let's say that I define with a number. 137 00:06:05,000 --> 00:06:05,000 Right. 138 00:06:05,000 --> 00:06:08,000 And if I go ahead and define over here age is equal to 30. 139 00:06:08,000 --> 00:06:11,000 See I'm getting an error saying that invalid decimal literal right. 140 00:06:11,000 --> 00:06:13,000 So I cannot start with a letter. 141 00:06:13,000 --> 00:06:14,000 So this is one way okay. 142 00:06:15,000 --> 00:06:20,000 The another way is that, uh can I define something like this first dash name. 143 00:06:20,000 --> 00:06:21,000 Right. 144 00:06:21,000 --> 00:06:22,000 Can I define like this. 145 00:06:22,000 --> 00:06:24,000 First dash name is equal to, let's say Krish. 146 00:06:25,000 --> 00:06:26,000 Can I define like this? 147 00:06:26,000 --> 00:06:27,000 Will I get an error. 148 00:06:27,000 --> 00:06:30,000 So here you can see cannot assign to expression here. 149 00:06:30,000 --> 00:06:34,000 Maybe you mean double equal to or instead of equal to. 150 00:06:34,000 --> 00:06:36,000 So this is not being considered. 151 00:06:36,000 --> 00:06:38,000 This symbol is also not being used. 152 00:06:38,000 --> 00:06:38,000 Right. 153 00:06:39,000 --> 00:06:43,000 Uh so obviously this is also an invalid variable name. 154 00:06:43,000 --> 00:06:43,000 Right. 155 00:06:43,000 --> 00:06:48,000 The third invalid variable name can I use at the rate and define a name variable. 156 00:06:48,000 --> 00:06:49,000 Right. 157 00:06:49,000 --> 00:06:51,000 So let me just go ahead and check it out. 158 00:06:51,000 --> 00:06:54,000 So here I'll go ahead and write Chris will I get an error. 159 00:06:54,000 --> 00:06:55,000 It says invalid syntax. 160 00:06:55,000 --> 00:06:57,000 Maybe you meant so and so right. 161 00:06:57,000 --> 00:07:00,000 So this is also not a valid variable name. 162 00:07:00,000 --> 00:07:03,000 It is an invalid variable name okay. 163 00:07:03,000 --> 00:07:06,000 And already I have spoken about case sensitive. 164 00:07:06,000 --> 00:07:07,000 Right. 165 00:07:07,000 --> 00:07:08,000 Case sensitivity. 166 00:07:08,000 --> 00:07:09,000 Right. 167 00:07:09,000 --> 00:07:12,000 If I define name is equal to Chris. 168 00:07:13,000 --> 00:07:17,000 And let's say I have defined capital name is equal to Naic. 169 00:07:17,000 --> 00:07:18,000 Right. 170 00:07:18,000 --> 00:07:20,000 Both this are different, right? 171 00:07:20,000 --> 00:07:21,000 It is not same. 172 00:07:21,000 --> 00:07:22,000 Right. 173 00:07:22,000 --> 00:07:27,000 If I really want to compare, can I compare like this num name double equal to capital name. 174 00:07:27,000 --> 00:07:29,000 It'll be giving false right? 175 00:07:29,000 --> 00:07:29,000 Yes. 176 00:07:29,000 --> 00:07:30,000 The values. 177 00:07:30,000 --> 00:07:31,000 If it is same it will give me true. 178 00:07:31,000 --> 00:07:35,000 But in short you can see that these are different identifiers, right? 179 00:07:35,000 --> 00:07:38,000 Later on I can do the comparison operation and I can do it right. 180 00:07:38,000 --> 00:07:40,000 So obviously case sensitivity is also there. 181 00:07:40,000 --> 00:07:41,000 Right. 182 00:07:41,000 --> 00:07:45,000 So this was related to something related to the naming conventions okay. 183 00:07:45,000 --> 00:07:51,000 Now let me just go ahead and make you understand about some of the variable types okay. 184 00:07:51,000 --> 00:07:55,000 So uh we will continue the writing the code here itself. 185 00:07:55,000 --> 00:08:02,000 So let me just go ahead and write understanding variable types okay. 186 00:08:02,000 --> 00:08:08,000 Now one thing you need to understand Python is dynamically typed. 187 00:08:08,000 --> 00:08:08,000 Okay. 188 00:08:08,000 --> 00:08:11,000 Dynamically typed. 189 00:08:12,000 --> 00:08:13,000 What does this mean? 190 00:08:13,000 --> 00:08:16,000 This means the type of a variable. 191 00:08:17,000 --> 00:08:22,000 Type of a variable is determined at runtime. 192 00:08:23,000 --> 00:08:25,000 Determined at runtime right. 193 00:08:25,000 --> 00:08:27,000 So this is very much important okay. 194 00:08:27,000 --> 00:08:32,000 And some of the important data types are like int float string and boolean. 195 00:08:32,000 --> 00:08:32,000 Right. 196 00:08:32,000 --> 00:08:35,000 So let's say if I write age equal to 25 right. 197 00:08:36,000 --> 00:08:40,000 So when I execute it during the runtime it will understand. 198 00:08:40,000 --> 00:08:40,000 Hey fine. 199 00:08:40,000 --> 00:08:42,000 Integer is basically getting assigned. 200 00:08:42,000 --> 00:08:44,000 So age is an integer variable right. 201 00:08:44,000 --> 00:08:48,000 And let's say that I will go ahead and define some more variables. 202 00:08:48,000 --> 00:08:48,000 Right. 203 00:08:48,000 --> 00:08:50,000 Let's say height right. 204 00:08:50,000 --> 00:08:52,000 I'm going to basically go ahead and define height. 205 00:08:52,000 --> 00:08:54,000 Let's say I'm going to write 6.1. 206 00:08:54,000 --> 00:08:57,000 So this this is nothing but it is integer. 207 00:08:57,000 --> 00:08:59,000 This is nothing but this is float. 208 00:08:59,000 --> 00:09:02,000 See how I'm also using the single line comments. 209 00:09:02,000 --> 00:09:02,000 Right. 210 00:09:02,000 --> 00:09:05,000 Let's say if I'm going to define my name. 211 00:09:05,000 --> 00:09:06,000 So this will basically be Chris. 212 00:09:06,000 --> 00:09:10,000 So this is what this is nothing but str the string. 213 00:09:10,000 --> 00:09:12,000 And finally if I go ahead and define is underscore student. 214 00:09:12,000 --> 00:09:15,000 This is basically my boolean variable right. 215 00:09:15,000 --> 00:09:16,000 So boolean. 216 00:09:16,000 --> 00:09:18,000 Uh sorry I will assign it as true. 217 00:09:18,000 --> 00:09:20,000 So this basically becomes my boolean variable. 218 00:09:20,000 --> 00:09:26,000 Now if I go ahead and print the type of any of this right like age. 219 00:09:26,000 --> 00:09:28,000 So I'm going to basically get integer. 220 00:09:28,000 --> 00:09:29,000 The class will be integer. 221 00:09:29,000 --> 00:09:29,000 During the runtime. 222 00:09:29,000 --> 00:09:30,000 It is able to understand it. 223 00:09:30,000 --> 00:09:35,000 If I go ahead and print what is the type of name I'm actually going to get string right. 224 00:09:35,000 --> 00:09:40,000 So similarly you will be able to find out different different types like what classes it basically belongs 225 00:09:40,000 --> 00:09:44,000 to Okay, now one more thing. 226 00:09:44,000 --> 00:09:50,000 Right here I will discuss about one very important point and understand one thing guys. 227 00:09:50,000 --> 00:09:51,000 Here I'll be showing some example. 228 00:09:51,000 --> 00:09:57,000 But when I go ahead with more session, more different lessons as we go ahead, right. 229 00:09:57,000 --> 00:09:59,000 I'll be reusing all this things. 230 00:09:59,000 --> 00:10:04,000 Don't think that I'm just going to write for a single time over here, because this all things will 231 00:10:04,000 --> 00:10:05,000 again get repeated. 232 00:10:05,000 --> 00:10:05,000 Okay. 233 00:10:05,000 --> 00:10:07,000 With all the different, different examples. 234 00:10:07,000 --> 00:10:12,000 Now let me just go ahead and make you understand about type checking and conversion okay. 235 00:10:12,000 --> 00:10:14,000 Now type checking and conversion. 236 00:10:14,000 --> 00:10:15,000 What does this basically mean. 237 00:10:15,000 --> 00:10:16,000 Obviously type checking. 238 00:10:16,000 --> 00:10:17,000 You have known right. 239 00:10:17,000 --> 00:10:19,000 So if I go ahead and write type off height. 240 00:10:19,000 --> 00:10:24,000 So that basically means I'm going to get the uh data type of this height variable. 241 00:10:24,000 --> 00:10:24,000 Right. 242 00:10:24,000 --> 00:10:28,000 So in short I'm actually getting float over here right now. 243 00:10:28,000 --> 00:10:29,000 My question rises. 244 00:10:29,000 --> 00:10:32,000 Can we convert one data type to the other data type? 245 00:10:32,000 --> 00:10:33,000 Is it possible? 246 00:10:33,000 --> 00:10:34,000 So let me just go and show you. 247 00:10:34,000 --> 00:10:38,000 Let's say if I go ahead and write age is equal to 25 right now. 248 00:10:38,000 --> 00:10:44,000 You know that if I go ahead and write print type of age, so what I'm actually going to get it is an 249 00:10:44,000 --> 00:10:45,000 integer, right? 250 00:10:45,000 --> 00:10:48,000 But now I am going to perform some type conversion. 251 00:10:48,000 --> 00:10:53,000 Type conversion basically means I am going to convert this integer value into a string value. 252 00:10:53,000 --> 00:10:59,000 Let's say So if I go ahead and write h underscore str, and if I go and use this str function, write 253 00:10:59,000 --> 00:11:01,000 str function is what string right. 254 00:11:01,000 --> 00:11:03,000 This is what is the class that I'm actually getting. 255 00:11:03,000 --> 00:11:07,000 Now if I want to convert this age into string I can use this str. 256 00:11:07,000 --> 00:11:09,000 And I can use this age variable over here. 257 00:11:09,000 --> 00:11:16,000 Right now if I go ahead and write print h print age underscore str okay. 258 00:11:16,000 --> 00:11:22,000 And after that I will just go ahead and write print type of age underscore HDR. 259 00:11:22,000 --> 00:11:22,000 Right. 260 00:11:22,000 --> 00:11:29,000 So if I go ahead and execute it see initially it was int later on uh when I printed this age underscore 261 00:11:29,000 --> 00:11:32,000 HDR here you can probably see that I'm getting 25 okay. 262 00:11:32,000 --> 00:11:35,000 But the type of this particular value is string. 263 00:11:35,000 --> 00:11:37,000 Right here you can see string. 264 00:11:37,000 --> 00:11:41,000 So this this value from integer it has got converted into strings okay. 265 00:11:41,000 --> 00:11:43,000 Now the question rises. 266 00:11:43,000 --> 00:11:44,000 Krish. 267 00:11:44,000 --> 00:11:46,000 Uh, what are different types of type conversion. 268 00:11:46,000 --> 00:11:47,000 Can I do okay? 269 00:11:47,000 --> 00:11:49,000 Can can I do something like this. 270 00:11:49,000 --> 00:11:50,000 Can I write. 271 00:11:50,000 --> 00:11:52,000 Age is equal to in string like 25. 272 00:11:52,000 --> 00:11:54,000 And can I convert this into int. 273 00:11:55,000 --> 00:11:56,000 Let's see. 274 00:11:56,000 --> 00:11:56,000 Right. 275 00:11:56,000 --> 00:11:57,000 Let's see this. 276 00:11:57,000 --> 00:11:59,000 So the answer is yes. 277 00:11:59,000 --> 00:12:00,000 You are able to convert it right. 278 00:12:00,000 --> 00:12:07,000 So if I go ahead and print uh the type of int of age, yes, definitely you are able to convert it. 279 00:12:07,000 --> 00:12:08,000 Right. 280 00:12:08,000 --> 00:12:10,000 And here I'm just going to close it. 281 00:12:10,000 --> 00:12:11,000 Yes the class is int. 282 00:12:11,000 --> 00:12:16,000 This is fine but still I will just go ahead and use one more. 283 00:12:16,000 --> 00:12:17,000 Some more examples. 284 00:12:17,000 --> 00:12:26,000 Let's say if I go ahead and write my name is Krish right now do I can I convert this into an integer? 285 00:12:26,000 --> 00:12:28,000 The answer is no, right? 286 00:12:28,000 --> 00:12:31,000 Because obviously Krish is a complete sentence, right? 287 00:12:31,000 --> 00:12:36,000 If I talk about 25 in string manner, this is basically a numerical value itself, right? 288 00:12:36,000 --> 00:12:40,000 So even though it is in a string, I can convert this into an int type. 289 00:12:40,000 --> 00:12:43,000 But over here this is my string complete string. 290 00:12:43,000 --> 00:12:45,000 I cannot just convert this into an integer type or a float type. 291 00:12:45,000 --> 00:12:50,000 So here you basically get an error saying that invalid literal for int with base ten Krish. 292 00:12:50,000 --> 00:12:51,000 Right? 293 00:12:51,000 --> 00:12:54,000 So this is the value that you are able to get it over here right. 294 00:12:54,000 --> 00:12:56,000 Another example some more example. 295 00:12:56,000 --> 00:12:57,000 Let's define some float value. 296 00:12:57,000 --> 00:12:58,000 Right. 297 00:12:58,000 --> 00:13:04,000 So let's say my uh my height is nothing but 6.1 okay. 298 00:13:04,000 --> 00:13:09,000 Or let's say 6.0 or 6.0 or 5.11 okay. 299 00:13:09,000 --> 00:13:10,000 Something. 300 00:13:10,000 --> 00:13:10,000 Okay. 301 00:13:11,000 --> 00:13:19,000 Now if I go ahead and see the type of height, what exactly it is, It is nothing but float, right? 302 00:13:19,000 --> 00:13:22,000 Can I convert this float into an integer? 303 00:13:23,000 --> 00:13:24,000 The answer is yes. 304 00:13:24,000 --> 00:13:29,000 So if I go ahead and write int and I do the typecasting for this particular height variable, you'll 305 00:13:29,000 --> 00:13:31,000 be able to see that I'm able to get five right. 306 00:13:31,000 --> 00:13:33,000 That basically means it is just going to remove the decimal. 307 00:13:33,000 --> 00:13:34,000 Right. 308 00:13:34,000 --> 00:13:35,000 Can I do the opposite again? 309 00:13:35,000 --> 00:13:39,000 Can I again typecast this from int to float again? 310 00:13:39,000 --> 00:13:43,000 Yes I can, and it is going to give me 5.0 right. 311 00:13:43,000 --> 00:13:44,000 So 5.11. 312 00:13:44,000 --> 00:13:47,000 Initially I converted this into an integer I got 5.0. 313 00:13:47,000 --> 00:13:49,000 Then again sorry I got five. 314 00:13:49,000 --> 00:13:51,000 And then again I converted that into float. 315 00:13:51,000 --> 00:13:52,000 So I got 5.0. 316 00:13:52,000 --> 00:13:57,000 So this is some example with respect to the conversion right type checking conversion. 317 00:13:57,000 --> 00:14:01,000 So this is what I really want to show you over here okay. 318 00:14:01,000 --> 00:14:03,000 Now let me do one thing. 319 00:14:04,000 --> 00:14:09,000 Let me talk about one very important concept, which is called as dynamic typing. 320 00:14:09,000 --> 00:14:10,000 Okay. 321 00:14:10,000 --> 00:14:13,000 And this is probably the most amazing feature in Python. 322 00:14:13,000 --> 00:14:13,000 Okay. 323 00:14:13,000 --> 00:14:19,000 Let's say I'm going to define a variable ten okay I'm going to define a variable ten okay. 324 00:14:19,000 --> 00:14:23,000 Now let me just go ahead and write print var. 325 00:14:25,000 --> 00:14:30,000 Where I'm going to print this var and I'm going to also print type of where. 326 00:14:30,000 --> 00:14:31,000 Okay. 327 00:14:31,000 --> 00:14:32,000 Type of where. 328 00:14:33,000 --> 00:14:33,000 Perfect. 329 00:14:33,000 --> 00:14:35,000 So this initially is an integer. 330 00:14:35,000 --> 00:14:37,000 Then obviously it should give ten. 331 00:14:37,000 --> 00:14:38,000 It should display ten. 332 00:14:38,000 --> 00:14:40,000 And it should say that hey it is an integer. 333 00:14:40,000 --> 00:14:48,000 Now Python allows the type of a variable to change as the program executes. 334 00:14:48,000 --> 00:14:48,000 Right? 335 00:14:48,000 --> 00:14:50,000 So let me write down this particular comment. 336 00:14:50,000 --> 00:14:58,000 Python allows the type of a variable to change. 337 00:14:59,000 --> 00:15:04,000 To change as the program executes. 338 00:15:04,000 --> 00:15:04,000 Right. 339 00:15:04,000 --> 00:15:05,000 Amazing, right. 340 00:15:06,000 --> 00:15:07,000 Now, what does this basically mean? 341 00:15:07,000 --> 00:15:11,000 Now I can go ahead and change the value of var and I can write. 342 00:15:11,000 --> 00:15:11,000 Hello. 343 00:15:11,000 --> 00:15:12,000 Okay. 344 00:15:12,000 --> 00:15:16,000 And let's say I'm going to print var comma type of var. 345 00:15:17,000 --> 00:15:17,000 Okay. 346 00:15:17,000 --> 00:15:20,000 This time obviously you know what it will output will be string. 347 00:15:21,000 --> 00:15:23,000 If you're not satisfied with this again you can change. 348 00:15:23,000 --> 00:15:27,000 So as you keep on executing the code you can keep on changing it. 349 00:15:27,000 --> 00:15:30,000 Let's say now this time I defined it as a float variable. 350 00:15:30,000 --> 00:15:36,000 Now if I go ahead and write print var okay var comma type of var. 351 00:15:36,000 --> 00:15:41,000 So if I go ahead and execute this here, you'll be able to see that I'm able to get this right. 352 00:15:41,000 --> 00:15:45,000 So see initially it was ten class int hello class str. 353 00:15:45,000 --> 00:15:47,000 And finally 3.14 class is float. 354 00:15:47,000 --> 00:15:49,000 So what is basically happening. 355 00:15:49,000 --> 00:15:54,000 Python is allowing this type of a variable to change as the program gets executed. 356 00:15:54,000 --> 00:15:54,000 Right. 357 00:15:54,000 --> 00:15:56,000 So we can basically do this. 358 00:15:56,000 --> 00:15:56,000 Okay. 359 00:15:56,000 --> 00:16:00,000 Now uh, let's do one amazing thing. 360 00:16:00,000 --> 00:16:06,000 Let's just create a simple, uh, application with whatever things we are specifically not. 361 00:16:06,000 --> 00:16:06,000 Okay. 362 00:16:07,000 --> 00:16:09,000 And before that, let me just talk about input. 363 00:16:09,000 --> 00:16:10,000 Okay. 364 00:16:10,000 --> 00:16:11,000 Now, what exactly is input? 365 00:16:11,000 --> 00:16:15,000 Let's say that, uh, a user wants to give some values, right? 366 00:16:15,000 --> 00:16:16,000 Let's say age. 367 00:16:16,000 --> 00:16:19,000 And I've told that hey, user, you give the value. 368 00:16:19,000 --> 00:16:21,000 What is the age? 369 00:16:21,000 --> 00:16:21,000 Okay. 370 00:16:22,000 --> 00:16:23,000 What is the age. 371 00:16:23,000 --> 00:16:24,000 So I, I am a user. 372 00:16:24,000 --> 00:16:26,000 I want to probably give the value over here. 373 00:16:26,000 --> 00:16:34,000 So if I use this right input function and if I print h over here, see what will happen. 374 00:16:34,000 --> 00:16:37,000 So once I execute this statement now see what will happen. 375 00:16:37,000 --> 00:16:40,000 So here you can see uh an input box has got opened. 376 00:16:40,000 --> 00:16:43,000 So here I'm just going to give my uh, age. 377 00:16:43,000 --> 00:16:45,000 Let's say the age is 23 okay. 378 00:16:45,000 --> 00:16:47,000 And I'm going to press enter. 379 00:16:47,000 --> 00:16:49,000 So here you can see I'm printing the age now. 380 00:16:49,000 --> 00:16:51,000 One very important thing to show you right. 381 00:16:51,000 --> 00:16:54,000 What will be the type of this age. 382 00:16:54,000 --> 00:16:54,000 Okay. 383 00:16:54,000 --> 00:16:59,000 So that basically means whenever I'm giving any input from this particular input box by using this input 384 00:16:59,000 --> 00:17:02,000 function, what will be the type of it by default type. 385 00:17:02,000 --> 00:17:04,000 So here I'm going to go ahead and write 23. 386 00:17:04,000 --> 00:17:06,000 And here you can see it is a string type. 387 00:17:06,000 --> 00:17:09,000 So let's say I want to probably get this particular input. 388 00:17:09,000 --> 00:17:12,000 And then also convert this into an integer or float. 389 00:17:12,000 --> 00:17:15,000 So I can again typecast this entire thing. 390 00:17:15,000 --> 00:17:15,000 Right. 391 00:17:15,000 --> 00:17:21,000 So now if I go ahead and execute this now, let me just go ahead and write 23 and press enter. 392 00:17:21,000 --> 00:17:22,000 So here you can see I'm getting a class hint. 393 00:17:22,000 --> 00:17:23,000 Right. 394 00:17:23,000 --> 00:17:30,000 So this is uh, one very important functionality for uh, uh, the entire, uh, input function over 395 00:17:30,000 --> 00:17:30,000 here. 396 00:17:30,000 --> 00:17:34,000 And uh, this can be very handy and can be used in various places. 397 00:17:34,000 --> 00:17:35,000 Okay. 398 00:17:35,000 --> 00:17:39,000 So, uh, I hope you are able to execute this and, uh, you are able to understand this. 399 00:17:39,000 --> 00:17:41,000 So I'm just going to show you one example again. 400 00:17:41,000 --> 00:17:43,000 Now let us do one thing. 401 00:17:43,000 --> 00:17:47,000 Let us simply create one simple calculator okay. 402 00:17:47,000 --> 00:17:50,000 Now this simple calculator will be amazing. 403 00:17:50,000 --> 00:17:55,000 So here you can just see that what this calculator is doing I'm giving two numbers. 404 00:17:55,000 --> 00:17:58,000 Uh again I'm using this input uh, number one. 405 00:17:58,000 --> 00:17:58,000 Again. 406 00:17:58,000 --> 00:18:00,000 Number two, then some. 407 00:18:00,000 --> 00:18:04,000 I'm doing num plus num one plus num two difference num one minus num two. 408 00:18:04,000 --> 00:18:08,000 And product is num one multiplied by num two num one divided by num two. 409 00:18:08,000 --> 00:18:11,000 We'll discuss more about this operators as we go ahead. 410 00:18:11,000 --> 00:18:14,000 And we are just going to display all the sum difference and all. 411 00:18:14,000 --> 00:18:15,000 So let's go execute it. 412 00:18:15,000 --> 00:18:17,000 Let's say the first number is 56. 413 00:18:17,000 --> 00:18:20,000 I'll go ahead and press enter again I've got my another cell. 414 00:18:20,000 --> 00:18:26,000 Let's say I'm going to write 43 or 10 something and press enter. 415 00:18:26,000 --> 00:18:31,000 So here you can see I'm able to see all the answers like some difference product and quotient. 416 00:18:31,000 --> 00:18:32,000 Right. 417 00:18:32,000 --> 00:18:35,000 So yes, uh, this was uh, amazing. 418 00:18:35,000 --> 00:18:40,000 This was I guess, you, you are able to understand many things about variables. 419 00:18:40,000 --> 00:18:42,000 Uh, this was it for my side. 420 00:18:42,000 --> 00:18:46,000 Uh, in the next video, I am going to probably discuss more about data types. 421 00:18:46,000 --> 00:18:49,000 And then finally we'll also be discussing about operators. 422 00:18:49,000 --> 00:18:50,000 What are the different different data types. 423 00:18:50,000 --> 00:18:52,000 Also we need to discuss about. 424 00:18:52,000 --> 00:18:53,000 So yes this was it for my side. 425 00:18:53,000 --> 00:18:54,000 I will see you in the next video. 426 00:18:54,000 --> 00:18:54,000 Thank you.