Python Full Course 2026 | Python Basics to Advanced Course in 24 Hours | Python Course | Simplilearn

Key Takeaways

Hi there, welcome to Simply Learns YouTube channel. Today we bring you Python full course, a complete learning program designed to take you from absolute Python basics to advanced realworld programming skills. Python is one of the most popular and versatile programming languages used today. It is widely adopted across domains such as data science, web development, automation, artificial intelligent, testing, and back-end systems. What makes Python powerful is its simplicity. Python allows you to focus on solving problems rather than struggling with complex syntax. In this course, we start right from the fundamentals, understanding Python syntax, data types, and control structures, and gradually move into advanced concepts like object-oriented programming, file handling, and real world applications. You'll learn not just how to write Python code, but how to think logically, structure programs, and solve practical problems using Python. By the end of this course, you'll be confident in writing Python programs, working with data, automating task, and building a strong foundation for advanced roles such as data analyst, data scientist, back-end developer or even automation engineer. Having said that, let's take a look at the agendas for today's course. We will be having a total of 12 modules in this full course. We'll start off this course with module one which is introduction to Python. In this module, we'll understand what Python is, where is it used and why it's become one of the most popular programming languages across industries. Once we have that foundation, we'll move into module two, which is Python basics. Here we'll learn core concepts such as variables, data types, operators, and basic input output, which forms the building blocks of any Python program. With the basics in place, we'll transition into module three, which is control flow statements. In this module, you'll learn how to control the flow of the program using conditional statements and loops to make your code dynamic and logical. Next, we will move on to module four, data structures in Python. Here, we'll explore list, tpples, sets, and dictionaries, and understand how to store, organize, and manage data efficiently. Once you're comfortable working with data structures, we'll step into module five, which is functions and modules. In this module, you'll learn how to write reusable code using functions and how to organize your programs using modules. Building on that, we'll move on to module six, which is object-oriented programming or OOP. Here we'll understand concepts like classes, object inheritance, and polymorphism, which help in building structure and scalable applications. After learning how to design programs, we'll focus on handling errors with module 7, which is exception handling and debugging. In this module, you'll learn how to identify, handle, and debug errors to make your Python program more readable. Next, we transition into module 8, which is file handling. Here you'll learn how to read and write to files and how Python interacts with external data sources. Once file operators are clear, we'll move on to module 9 which is working with libraries and packages. In this module, you'll understand how to use Python standard library, install external packages, and work with popular libraries used in real projects. With that knowledge, we then move on to module 10, which is automation and scripting. Here you will learn how to automate repetitive task, write scripts, and use Python to improve productivity. After that we bring everything together in module 11 which is real world Python projects. In this module you'll apply all your learning to practical projects strengthening your problem solving and coding skills. Finally we conclude the course with module 12 which is Python career readiness. Here we'll focus on interview preparation best practices and next career paths where Python skills are highly in demand. Hope I made myself clear with the agenda. That's it. If these are the type of videos you would like to watch, then hit that subscribe button with the bell icon to get notified whenever we post. Also, just so that you know, if you want to upskill yourself, master data science and data analytics skills and land your dream job to grow your career and then must explore SimplyLearn's cohort of various data science and data analytics programs. Simply learn offers a variety of masters, certification and post-graduate programs in collaboration with some of the world's leading universities like Peru University, IIT Gujhati and many more. Through our courses, you will gain knowledge and work ready experience in skills like Python, Tableau, PowerBI, Generative AI and over a dozen others. That's not all. You'll also get an opportunity to work on multiple projects led by industry experts working in top tier data and product companies. After completion these courses, thousands of learners have transition into data science and data analytic roles as a fresher or move to a higher paying job and profile. If you're passionate about making your career in this field, then make sure to check out the link in the pin comments and in the description box to find a data science and data analytics program that fits your experience and areas of interest. So, let's get started with our data science full course with a small quiz. Which of the following best describes the primary goal of a data science? Writing complex code using Python. Storing large amounts of data. Extracting insight and making predictions from data. creating dashboards only. Please let us know your answer in the comment section below. Now over to our training experts. >> Let us try to install Python. So for this tutorial, I'm using Windows as operating system to install Python. Go to the official website of Python and you can see Python downloads will be there. Just click all over here and you'll be directed to this URL. Now click on download Python install manager and you can see this is going to get downloaded. After this click on all over here and let's maximize this. So guys since I have already installed Python so it's showing me reinstall Python but but for you it is going to show install Python. So you have to click all over here since I won't be doing it. So I'll be directly launching my Python. Now you can see are you're going to get some terminal like this. So you can click on yes and start it. But I won't be doing it because I have already installed Python. And the next step that you need to do is go to your given command prompt. And here you need to type Python version. And you can see all over here you're going to get the required Python version. Now guys, I hope so you have got a brief idea like how we have installed Python. Now let us try to run some of the given code in Python. Now for running the given Python code, I would suggest you to install PyCharm which is amazing ID for the Python based projects. So go all over here and type PyCharm download and this is powered by Jet Brains. So all you can do all over here click on download. So accept all click on download and it is going to be downloaded for you. Very amazing ID guys. Do try this out and let us know how do you feel about this ID in the comment section. Now guys let us create one folder all over here. Click this folder and let's say it's a Python folder. So Python demo you can type. Okay. Now open this folder and let us try to create one file. Let's go to new and create a file [snorts] and you can give this name as a hello. py. Okay. Now open this given file in the terminal. So now guys after that you need to type python hello. py. So we have created hello world from the command prompt only. Now just click all over here and you are going to see a hello world written. Now this ensures that you have successfully installed Python and you have tested your first command. >> So let's begin. What are tpples? A tpple is a collection of immutable heterogeneous Python objects. So the extra term that comes in case of tpples are that they're immutable. So over here we have a tpple that's x and within x we'll store various elements 1 89 a single letter a which is a string also a word which is again a string in python hey o and b. So as you can see this tpple here may not be necessarily completely filled with integers completely filled with floats or strings. It can be a mixture of all of these data elements. So that is one advantage we have when it comes to tpples and lists as compared to arrays. Because with arrays you can have only one data type elements within it. Now we look at indices. So every element in a tpple takes up a position and this position is what we refer to as an index. In plural that's indices. So tpples positioning or the indices for tpples and list strings also in case of Python and most other programming languages starts with zero. So your element one is at the zero position. your element 89 is at the first position and so on where b is at the fifth position. So in a way you can say that the length of your tpple x is six but then the last index of your tpple x is five because it starts from zero onwards. So now that we have a basic idea of what a tpple is let's begin with creating tpples. Creating tpples. Now the first thing that we're going to do is we'll create an empty tpple. So say my empty tpples name is emp. All you have to do to create an empty tpple is give these curved brackets with no elements inside. So this is a lot like list but in case of lists we had square brackets. In this case we have curved brackets. So that's the only difference. Now if I print the type of emp you'll see it's of class tpple. I can also print out just emp. And since emp is an empty tpple there's no element within it. But then of course the brackets are still printed cuz that's a list cuz that is the basic characteristic of a tpple. So even if it's empty these brackets would still be existing. So we saw how to create empty tpples. But how often do we actually use empty tpples? So let's put some elements into our tpple. So let's start with creating a tpple with just one element. So say my tpples name is city and I'll have one element pune. If you're creating a tpple with one element, if you're not putting the brackets, it's completely valid as long as you have a comma after that particular element. So with this kind of a syntax, you can create a tpple. So I'll create a tpple say city and I'll just have one element within this which is pun. Now if you're not putting this element within these curved brackets that's very characteristic to tpples, it's completely okay while creating a tpple as long as you have a comma after your element. So although you have no element after this comma that one single comma is important. So let me run this and just type of city. As you see city has been stored as a tpple. Now in the most standard way of creating tpples you'll say city and within brackets you'll pass your element also print out city after that and the same syntax can be used and then you can also combine these both. Although that's completely unnecessary effort but it's possible it does not result in an error. So you have your brackets and the comma works just fine. Now I want to add more elements to city cuz clearly Pune is not the only city we know. So Pune Bangalore these are some of the cities in India if you're from another country and wondering. So after this demo you not only know tpples you also know a few cities in another country. So I have four elements in this tpple and this is how you create it. all the elements separated by commas and within brackets print out city. Now I can do the same thing without the brackets too. Just the commas indicate that this is a tpple. Now those are the various ways you can create a tpple. Of course all these ways do not come handy. Usually you use this method to create a tpple with n number of elements and when it comes to one element you usually go for this just put one element within the brackets. This is also used sometimes. Now another thing we saw while learning what a tpple is or looking at the definition of a tpple is the word immutable. So we said lists are mutable which means that they can be changed and tpples are immutable as in they cannot be changed. So here we'll see a small example as to what the difference between tpples and lists are when it comes to the execution of these both. So say I have a list list one and that has elements 1 2 3 4 and then I have a tpple say tpple one which has the same elements 1 2 3 and four. Now with list one I'll use this method that you probably have encountered before called append. So I say list dot append of five. So what this function does is it adds five at the end of this list which is list one. Now we'll print out list one. run this code and as you can see here five has been concatenated to our list one. Now let's try the very same thing in tpple. So tpple one dot append five and I'll run this and see you get an error here. So the tpple object has no attribute append. In fact it has none of the functions which you usually use with lists because these functions aim at changing the original list and not giving back a new list. In tpple's case, you cannot change the original list. Once your tpple is set, that is how it's going to be as long as it exists. So that is the main difference between lists and tpples. List is mutable whereas tpple is immutable. And other than that, of course, you must have noticed the syntactic difference which is lists are with square brackets and tpples may or may not use parentheses or the curve brackets. So every time you print out a tpple or you view a tpple, it's always got those brackets. But as you saw while creating a tpple, sometimes a comma is enough. So now let's access these elements in a tpple. If you want to print out the entire tpple, we already saw just put it in a print statement. Put the tpple list. Put the tpple name in a print statement and you'll have your tpple printed. Now if you want to access some particular element of the tpple, say I want to take out Bangalore. So in that case we use the indices as we saw earlier. indices start from zero and Bangalore is therefore at the first position. So I have to just say city and within square brackets one. So this particular line or the syntax is exactly the same as you would use for a list or string. Just run that and here we go. We have Bangalore. Now we can also extract elements from the end of the string just like we did in case of list. So if I do not know the length of the string. Now suppose I want to access the very last element of my tpple but I have no clue as to what the length of my tpple is. In that case what index do I use? Well I can just go with minus1. Now every time you give this minus sign it starts accessing elements from the end of the tpple. So minus1 means the first element from the end of the tpple which is Mumbai and that's what we got as our output. Now although lists are immutable there are a number of operations you can still perform on them. For example, the very first thing we look at is concatenation. So I already have my tpple city. We'll just print it out once again here to see what it consists of. Now we'll create another tpple say num. And this will have the elements 1 2 3 4. Now sure I can't modify tpples but I can definitely concatenate these two. So how do you do that? Extremely simple. City plus num. The plus sign works perfectly fine for concatenation. So I will print this out. And we have an error here. That is because we have not compiled our num list first. So our num list is not existing right now. I ran my line 19. Now I can run the next line. We have one complete list which has all the elements of city followed by the elements of num. Now you can also nest tpples. That is you can have one tpple within another tpple. So so far we have a tpple city and num. Now I will create another tpple. So first now we already have a tpple city and num. What I'll do is I'll create a new list say nest. So this is going to be a list. So we have our brackets here. So what I'm going to do is I'm going to create a tpple within another tpple. So we have a new tpple. I'll call it nest. And since this is a tpple the basic syntax I'll have the brackets. Now what will be the elements within this? The elements would be my other two tpples which are city and num. So I put in both my elements here and let's see what nest contains now. So nest is a tpple which itself contains of other tpples which are city and num. So that is how you nest tpples. Extremely simple, isn't it? Now here's something else. Say I want to create a tpple rep which has an element python but that element is repeated five times. So what you would generally go for is type out python five times. But thank god for python there's a much simpler way of doing this. Type in Python once and multiply this five times. Let's print out rep now. And as you see here, Python exists within this tpple five times. 1 2 3 4 5. Now maybe this is not how you want to create your tpple. You want your tpple to just have that one element python initially but later on while printing you decide you know what I want Python to be printed 10 times within this tpple. Not a problem. put your tpple name here and then go for it into 10. And as you see here, the tpple has now 10 elements within it. So guys remember when you're putting the statement here, it's not actually modifying the tpple. It's just printing it this way. So if I say rep once again and I run this, this tpple just has one element. So next we look at slicing in tpples. So we created our tpple num previously. I'll just print that out once again. So it has the elements 1 2 3 4. Now suppose I want all the elements from two up till the end of this tpple to be printed. In that case what I do is I go for slicing where I will mention my beginning and my end index. So my beginning index starting from two is of course one and my end index is basically the position four is at or till the end of this tpple. Now when I want all the elements up till the end, I do not need to mention my end index. It's by default taken. So if I just say num of 1 up till black run this your tpple sliced it gives out the elements at the first second and third position considering zerooth is our first position of course now you can also print this num tpple in reverse using these indices so you say num I leave my start and end index empty give two colons and then in the end I have minus one so when you put this minus one here so it basically prints out the reverse of of your tpple. Let's check that out. And as you see, your last element is now your first element and your first element is now your last element. If you have any doubts regarding how slicing works, please check out our video on Python lists. Over there we have a detailed description on how slicing is and there will be no confusion since in case of slicing at least tpples and lists are exactly similar. So let's look at this string that I have here simply learn. Now I want every letter of the string simply learn to be an element of a tpple. How do I do this? Well pass the string as a tpple. So write tpple of and within this you have your string which is again within quotes. Right? We'll run this command. And as you see here every character is now a separate element in a tpple. So this procedure is called unpacking. Now I'll just print out my num tpple once again so we can see what's in it. Okay. So I want to put these elements which are inside a tpple into various variables. Now in this case I know that my tpple has four elements. So I can have four variables A, B, C, D. And I'll put this equal to num. Run this. And then I'll print out A, B, C, and D. So every element of the tpple has gone into one of these variables. The first element went into A. Second element into B and so on. Now what if we had no clue how many elements are there in num. In that case I could say a I want my first element to go into my first variable a no matter what and I want my last element to go into this variable c no matter what. Now all the elements in between I'm not very concerned about where they go. So in that case I can have another variable B but this variable will be a list. So the star indicates that B is a list and then this is equal to num. We print out A, B, and C. So you see what happens here is my first element went into A and my second element went into C cuz these were clearly indicated. But every other element in between went into my list B. So that is how unpacking works. So since tpples are immutable, it's impossible to delete the elements within it. But that does not mean you cannot delete the tpple entirely. So that is what the Dell keyword does. We'll implement this. So I'll create a tpple tpple 1 and put some elements into it. 1 2 3 4. Now I'll use the dell keyword. Now I'll just print out this tpple. So we know it exists and what all elements are within it. So great, our tpple's created. It has the elements 1 2 3 4 within it. Now I'll use the dell keyword to delete this tpple. So I say dell space followed by your tpple name. Run this command. Now let's try printing tpple one once again. Of course, since we did it all right, hopefully this tpple should not exist and this should result in an error and it is resulting in an error. It says tpple one is not defined. So you can completely delete the tpple if not delete elements within the tpple. So as I mentioned previously, most of the methods that you have with list does not work with tpples because these methods change the original list itself. But there are a few built-in functions which do work with tpples. They return values or new lists and they do not have any impact on the original tpple. So it works just fine. We'll explore some of these built-in functions. I'll continue using the tpple I created before that's num. So I'll create a new tpple num one which has the elements 3 5 say 4 2's 6 5 8. And now we'll perform our built-in function operations on this num one tuple. So the first one that we look at is counting the number of occurrences of a particular element. So that is the count function. So you give your tpple name dot count of and the element whose count you want to know. So I want to know the number of twos in my tpple num one. Run that and as you see there are four twos. Now you can also find the sum of all the elements within your tpple. So that is sum of num one. You just have your function sum pass num one to it. Now this sum function works for tpples, lists, everything. It's not a function particularly for tpples as such. So the sum of all the elements within a tpple is 35. And in a similar way, you also have the len function which is in fact even used for strings. So len of num one gives the number of elements within num one which is 9. We have nine elements. But remember our last index is 8 not 9. Our element is 82 coincidentally. Now we have the max function for finding out the maximum number in your tpple. So say max of num one which is eight. And we also have a function for checking the minimum of the numbers within a tuple which is two in this particular case. So now list and double are very similar in the sense of what they hold. So what if I have a list say lst which holds the elements 1 2 3 4 and I want to convert this list to a tpple. So we'll see how that is done. First I stored my list 1 2 3 4. So I'll just check the type of the variable lst. Ensure that it's a list which it is. Now we can convert this to a tpple. So to convert this to a tpple, enter your variable name and then pass your list name within these braces for the method tpple. Run this code. And now let's print out tpl. And as you see our list lst has been converted to a tpple. We can also check its type. So yeah, a conversion has worked out fine. Now this kind of a situation often arises when you put certain elements into a list. So you create a list that you desire and then you realize that you don't want this to be changed at all throughout the program. So then you can convert the list to a tpple. You cannot convert a tpple to a list though. So we previously saw how we can have nested tpples that is tpples within tpples. Now we can also have tpples within lists. So we'll check that out now. Say I have a list LST and within this list I'll define my tpples. So two of the elements of my list LST will be separate tpples. I have a tpple 1 2 3 and I'll have another tpple as the second element of my list as 4 5 6. So I'll run this code. Print out LST. So LST is created just fine. It's a list which holds two tpples. Now tpples are immutable but lists are mutable. So we can add as many tpples as we want inside this list. So we can make modifications to the list. So I could say list.append and to this I'll pass another list which has three elements. Say tuple inside list. Run this code. Now if I print out list you'll see that the third tpple has also been added to the list. Now we can also remove tpples from the list. Just use the remove function. So lst dot remove and within this I'll pass the list that I want removed which is my first list in this case. So run that code and print out the value of lst to check what's in it right now. So our first list has been removed. Now we just saw how you can nest tpples within lists. Now we'll check out how we can nest lists within tpples. So I'll create a tpple tpl and within this tpple I'll have two elements each of the elements being a list. So they have a b c in my first list and d e f in my second list. Run this and print out the value of tpple before we proceed. Yeah. So that's our tpple with two elements. Each element a list. Now we cannot modify tpples. So initially when we had tpples within list, we could add more tpples to that particular list. But now we have lists within tpples and we cannot add more elements to this already defined tpple. But what we can do is we can modify the list within the tpples. So I can add elements to the first element and the second element of my object tpple. So I'll try that out. If I say tpple0 dot append. So when I say tpple0 it's accessing the first element of the tpple and the first element of a tpple is a list. So to this I can use the append function and I'll append an element Z run this code and then check out the elements within tpple and in the similar manner we can also remove elements from the list within this tpple. So I can say tpl of zero dot remove z and then print out tpl. So you see z has been removed here. Now just for the sake of it let's see what happens when we try to add another list to this tpple. So I say tpl dot append and pass a list x y z and then print out tpl. So we get an error because this time our object was a tpple not a list and tpples cannot be changed. So with that we saw the many concepts that is used with tpple along with what tpple is. We'll quickly now have a very short exercise where we'll recall some of the concepts that we previously saw in this video. So what is this exercise that we're planning on doing? We'll initially create a tpple which has the digits from 0 up to 9 called tpple one. And then we'll create another tpple by adding an element to this tpple one. So we are not adding an element to tpple one and modifying the original tpple but we creating another tpple using the elements in tpple one and adding another to it. Then we'll create a tpple by adding the reverse of tpple one to this tpple. So first we have tpple one which has all the elements then tpple two which has all the elements of tpple 1 plus another number and then we have tpple three where we have all the elements of tpple 2 plus the reverse of tpple one. So let's move on back to the jupitter notebook. I'll create my tpple which is called series 0 1 2 3 4 5 6 7 8 9. So that's my first tpple and I'll print this out. So a tpple's created. Next thing we do is we create our second tpple which is series 1. Now series one will have all the elements of series plus another element which is 10. So how can we add another element to a tpple if we are using so how can we add another element to this tpple without manually typing it out. Now as we saw previously we can concatenate tpples. So we can say series 1 equal to series and we'll add the second element as an element of another tpple. So instead of just saying 10 which is not possible cuz series is a tpple and 10 is an integer we can say a tpple which just consists of 10. Run this code and print out series 1. So we have successfully been able to add another element to series and create another tpple series 1. Now we have to create a third tpple series 2 which will have all the elements of series 1 plus the reverse of series. So again we're going to use concatenation to bring both these tpples together. Say series 3 equal to series and of course I can just say series and plus but just for the sake of recalling once again how slicing works. So I'll put in 11 here. And now to that I'll add the reverse of series and not series one. So I'll just make this correction in the previous one. It's supposed to be series one here and not series. And here I need to reverse it. So as we previously saw, I'll put minus one here and leave the beginning and end indexes empty. Run this and print out series 3. So we have all elements of series plus the 10 which makes up series 1 and then the reverse of series. So here's a very simple statement. X equal to 100. A variable's definition is basically an entity of a program that holds a value. So in this case, x would be our variable and 100 would be the value it holds. To better visualize this statement, let's consider a box. Now if this box holds a value, say 100, then the name we give to this box, which in our case is x would be the variable name and 100 that is a content within the box or within the variable would be the value of the variable. Now this is the basics of what a variable is. As we'll go through the various topics today, you'll have a better understanding of why we use variables and how to use them. So let's move on to the next topic which is the various data types of variables. Before we move on to this, let me explain to you what data types are. If you have dealt with other programming languages before, you probably already know what data type is. But just in case you haven't, data type is basically the type of value that you assign to the variable. So in our previous example where we said x equal to 100, in layman terms, 100 is a number. So the data type would be number. But when we come to programming languages, there are two types of numbers. There are integers and there are floats. Integers are basically numbers without decimal point. Floats are numbers with decimal point. Other than this, a very common data type that we have in Python and other languages is string. So string is any word. In technical terms, we call them a collection of characters. Python also has a few of its own data types as we will see. So let's move on. So I'll move on to my Jupyter notebook. So the first data type that we'll be looking at is integer. As you saw in our previous example, x equal to 100 is an apt example for this. Let me run this statement. As you can see there's no error. That means this assignment is proper. Now we'll check the type of this variable. So type and within brackets you enter x. Run this. And as you can see the type is int. So int is the short for integer. Any number without a decimal point comes to int in Python. Now this is not the only way you can assign values to variables. You can also assign values to variables while simultaneously performing arithmetic operations on them. So 654 into 6734. Enter. Now let's check out the type of this variable which would be int again. Now if you print the value of this variable, you'll see that the value x stores is the product of these two numbers. So now let's move on to the next data type which is float. x = 3.14. As you can see, this is a number with a decimal point. If you run this, there won't be any error. So, this is a proper assignment statement. You print x and the value is printed. Now, you print the type of x run. And it's float. We'll move on to our next data type which is strings. So, string is any word. It's a collection of characters. So x equal to and within quotes. So I'll type simply learn and run. So no error print x and the value of x is printed which is simply learn. So guys whenever you're assigning strings to a variable it's important that you do them within quotes. Now you can do them within single or double quotes. I'll show you how it's done within single quotes and the exact same output. So it does not matter whether you use single or double quotes. Now let's check out the type of this variable. Type X and str which is a short form for string. So now that we had a look at integers, floats and strings, let's move on to some of the data types specific to Python. The first one we look at is lists. So a list is basically a collection of values. So far we assigned a single value to a variable. With lists, we can assign multiple values. And this is how it's done. So give the variable name equal to open square brackets. And within this you type your values. So 14 67 9. Run this. No error. Now let's print x and see what this results in. As you see when you print x all the values you stored within it is visible. Now let's check out the type of x and the type is list. Now with list since there are multiple values stored within a variable you might be wondering how you can extract a single value. So this is simple each value in a list has an index. So you always start with zero. This is the zeroth position first position second position. So if you want to extract 14 then you type print x0 and that will display 14. If you want to print the last value print x2 because we start from zero so this is 1 and this is two. So that should print 9. Great. Now we'll change the values which are stored within the list. So if I say x2 which right now is 9 but I want to change this to 67. So that is a simple statement how you can do so and run. Now let's see what x holds. So when you just type x you're printing every value within x and when you give a particular number within the square brackets with x you're printing the value at that particular location. So print of x run and as you can see here guys previously x held 14 67 9 now it holds 14 67 and 67 again because we changed x of 2 to 67. So now that we're done with list we'll move on to another data type in python. This is called tpple. So with tpple 2 it's about the same thing. You can store multiple values in a single variable. The syntax for doing so though is slightly different with doubles. So instead of square brackets, you now have round brackets and within that you type in your values. So I'll just put 4 8 6 and let's print x. So all the values within x is printed. Now let's check the type of x and the type gives tpple. So you might be wondering what is the difference between list and tpple. Now the core difference between list and tpple is that tpples are immutable. So what I mean here is that in case of tpples 2 you access each value within it in the same way you do with list. So if I want to access the value 8 in x right now I'll just give x within square brackets 1 print this and it outputs 8. But now if I want to change this value so the way of doing that as we saw with list is x of 1 and the value I want to change it to. So let's say five and I run this we get an error. So you cannot change the values in case of tpples. Once you have stored the value within the variable for a tpple it remains that way right till the end. And in technical terms this means that tpples are immutable while lists for which you can change the values they are mutable. So now we have something slightly different. When we deal with files, we need a variable which points to a particular file. So in general, these are called file pointers. The advantage of having file pointers is that when you need to perform various operations on a file, instead of providing the file's entire path name or the file's name every time, we can just assign it to a particular variable and use the variable instead. So this is exactly the advantage variables have with all other values too. But the syntax for doing so with files is slightly different. So I give x equal to open and within brackets open quotes enter your file name. So I want to open say a file called variable com and this is IP ynb. So it's my python notebook and the mode I'd like to open it in. So R let me run this. No error. So it's fine. This kind of an assignment is completely legit. Now we'll check the type of X. So as you see here the type for X is io.ext io wrapper. So in Python this is the particular type assigned to this variable. But in general terms you can refer to them as file pointers. Now suppose you want to assign values to multiple variables. What you can do here is instead of having statements like x= 5 enter y = 10 enter z = 7. Instead of having three such statements delete open bracket x y z within bracket equal to 5 10 7 and this works exactly the same. So now if you print X, Y and Z, you'll see that they have been assigned the respective values. Of course the number of variables and the number of values on either side should match. So if you put X= to Y. So if you give x y = 5 10 7 this would result in an error because you have only two variables on your left hand side while you have three values on your right hand side. Now suppose you want to assign the same value to multiple variables. In that case you can do now suppose you want to assign a value to multiple variables. Say x = 1, y = 1, z = 1. A short form to this as you saw previously would be xa ya z = 1a 1a 1. But then again, you'll have to type the same value three times. Instead, what we can do is x = y = z = 1. And this would work perfectly fine. So if I print the value of X, Y and Z now they all have the value one stored within them. So we have covered the various data types in Python and how you can assign values to a variable in multiple ways. We'll next move on to the various rules for naming the variables. Now there are certain rules that you must follow while naming the variables. We'll go through each of these rules and simultaneously I'll also demonstrate to you in our notebook the validity of each variable. So our first rule is variable name must begin with an alphabet or an underscore. So let's move on to our notebook. So ABC equal to 100. This should be valid because it starts with an alphabet. At the same time underscore ABC would also be valid. So if the variable starts with an alphabet or an underscore, it's a valid name for the variable. But if we say 3 a equal to 10, this would result in an error. Of course, cuz the variable name starts with the number and this is invalid. Same way we cannot start the variable name with the special character other than underscore. So if I say at the rate ABC, this would also result in an error. As you see the error is invalid syntax because that is the invalid syntax for a variable name. Let's now look at the second rule for naming variables. The first character can be followed by alphabets, numbers or underscore. So our first character must be an alphabet or an underscore. And after this first character we can have alphabets, we can have numbers or we can have underscore. So back to our notebook by the second rule a 100 should be valid as it is and if we put underscore which is a valid starting character a 984. So our first character is followed by a letter three digits and then another underscore. This should also be valid because at the end of the day it only consists of numbers, letters and an underscore. However, if our variable name is a 99 67 few digits and then a dollar sign, would this work? Well, no. This would result in an error invalid syntax because as already mentioned for variable names the only special character you can use is underscore. What about xyz hyphen 2? Again this would be invalid because it includes a special character that is not underscore. Can't assign to operator. Let's have a look at our third rule. Variable names are case sensitive. So what case sensitive means is that small letters and capital letters are treated differently. So let's move back to a notebook and say I assign a value 100 to a variable a 100 small a and I assign another value 200 to a different variable capital a 100. So as you see here guys between these two variables the only difference is that the first variable has a small a and the second variable has a capital a. Let me just execute this. If I print the value of a00 and capital a00 you'll see that both these variables are recognized as completely different variables. They have their individual values. So now that we established that variables are case-sensitive, we can also say that Python itself is a case-sensitive language. Now a final rule is that reserved words cannot be used as variable names. Now if you have gone through any other languages like C, C++, Java, you know this is a common rule among all of them. You cannot use words which have special meaning to the language as variable names. So some of these words are break, class, try. You have other words such as continue, while which is a loop or if which is a statement, a conditional statement. So let's go back to our notebook and see how assigning values to these reserved words can result in errors. So if I give break equal to 10, that would be an error. Similarly, class equal to 5 would result in an error. Try equal to 100 would also result in an error because these words break class try have special meaning to Python. And with that we cover the various rules for naming variables. The next thing we'll check out is the arithmetic operations that you can perform on these variables once you have stored integer values in them. also perform various arithmetic operations with variables that store integer or float values. So let's have a look at some of these operations that we can perform. We'll start with initializing two variables. So x= 20 and y = 10. And now we'll perform our operations with these two variables. So first let's check out how addition works. Result equal to x + y. So result is a new variable and it should store the value of x + y. Let's print this out and as you see x + y = 30. So now result stores 30. Similarly we can perform subtraction. We'll print this out too. So 20 - 10 is 10. We can also perform multiplication. We use asterisk for the multiplication sign. So 20 into 10 that's 200. Next we'll check out division. So as you can see here in case of division the result is not an integer but rather a float. If you want your result in integer what you can do is instead of putting just one slash you can apply two slashes. So x/y and print the result and there you go. Now you have the result in integer. So in this particular case since 10 completely divides 20 the requirement of the double slash is not very visible. But if we do division for numbers that do not divide each other completely. For example, if we have result equal to 2x3 and we print the result, we get 0.66 and so on. But if we give double slash here and run this, we get the result as zero. So in a lot of cases, the result from double slash makes way more sense than from single slash. So this is an extra benefit you have with Python which is not present in many other languages. We also have the modulus operator here which gives the remainder rather than the quotient. So if I say x mod y it'll give me the remainder of the division from x by y and the remainder is zero because 10 completely divides 20. On the other hand, if you do want to see the remainder, you can give numbers such as 3x3 mod 2 and then print the result. And as you see, the remainder of this operation would be one. Now, so far we saw arithmetic operations with integers. All these operations can also be performed with floatingoint numbers. So if your x value is 3.14 and your y value is 5.7, let's just perform one operation using the new values of x and y to see what it looks like. So let's say result equal to x by y print result and there's your quotient. So arithmetic operations work both with integers and floatingoint numbers. Next, let's check out some of the operations you can perform on string variables. As I mentioned earlier, strings are basically a collection of characters. So let's look at a few string operations. First, we'll initialize a string variable. So v equal to simply learn and we'll perform all our operations on this variable. Now the first thing we'll do with this string variable is we'll see how we can extract each character in string. So just like in case of list and tpples every character in your string has an index and it always starts with zero. So the first character is at location zero second at one third at two and so on. So if you want to extract the first character of your string which is s in our case we just do v of zero and as you see s is printed. Similarly if you want to extract the fifth character of our string we'll put of four. So if you want to extract nth character your index for it would be n minus one because we start our index from zero and that prints l. So as you can see here S is zero and then we have 1 2 3 4 and that is L. So now that we learn how to extract a single character let's see how we can extract multiple characters from the string. Suppose I want to extract the first three characters. In that case I would say V of the first three. So my starting character would be at zero. So if I want to extract the first three characters of my string, what I'm basically saying is that I want to extract the character at the zero, first and second position. Then I'd say print of bad of starting from the zeroth location up to the third location. We say three and not two because the last index is always excluded. So if I put two here instead of three then only the zero and the first character would be printed. So I want my first three characters to be printed. So pair of 0 to 3 and I'll run this. And as you see the first three characters have been printed capital S followed by I M. Now if you want to start from your first character you can also just ignore the zero. So you can say v of colon 3 that is we are not typing the zero in this case. It's automatically understood that you start extracting from the first character when you miss out the zero. So you run this and as you see it's the same result. Now if you want to print the character starting from the fifth location until the end of the string you can go with print of v of fifth character. So five and up to the end. In this case, you do not need to mention the last index. You can just leave it blank and it's automatically understood that you're printing till the very last character of your string. And as you see from your fifth index to the very last character has been printed. Now suppose you give v of 0 to 20 and it's pretty obvious that you do not have 20 characters in this particular string. So you do not have 20 indexes. So what do you think would happen if I do 0 to 20? Well, the entire string is printed. So although we have only 11 characters in our string and we have given the ending index as 20, this does not result in an error. Just our entire string gets printed. Now if you want to find out the length of your string without actually having to count it manually, you can use the function len of where. Len is an inbuilt function in Python. Now run the command. And as you can see we have 11 characters in a string. So those are the basic operations you can do with a string variable. I hope this is very clear to you as in the end we have a small quiz which uses some of these concepts. So now that we have gone through the various concepts of variables. Let's have a small exercise where we'll be using string variables. So we'll have two strings. One string says it's Sunday and the other stores have a great day. Using only these two strings, we need to build a third string which says it's a great Sunday. So let's have a look at how to do this. We move back to our notebook. The first thing to do is we store our two source strings in separate variables. So let's have variable v one which stores our first string. It's Sunday. And we have the next variable v two which stores our second string have a great day. Now using these two strings we create our third string which is v3. So first let's run these two statements. So now v 3 needs to store it's a great Sunday. The word it comes from v one. So v one and it starts at the first location. So zero which we can ignore cuz it's automatically assumed to be zero. And we require all the characters in v one from the zeroth position until the position just before our capital s of Sunday. So that would be 0 1 2 3 4. So our fourth position is the blank space. Since we want to include the blank space too, we give our ending index as five. Now the next part of our string it's a great Sunday needs to include a great from where two. So where two. So the next part of our string is a great and a great comes from where two. Now this subscript starts from the fifth position in V 2. So our starting position would be five and at the 12th position in V 2 we have the space that comes after grade. Now we need to include the space too. So we'll go with our ending index as 13. And finally our last word of it's a great Sunday which is Sunday will come from v one. So v 1 and the word Sunday starts from the fifth location in v 1. So our starting index here would be five. And we'll take the entire string from the fifth location. So we leave the ending index empty. And that's it. S