Python 101: Coding For Beginners

1. Introduction: While most people think that this is what programming looks like, it's actually much easier and simpler than you could ever have imagined. Don't believe me, have a look at what the experts have to say. It's a skill that is very accessible. It's not like a rocky science. It's not like you have to know everything. You can do a lot of it by yourself. You don't need anybody's permission to do anything. You can just break things and it just build back up, nothing happens. You don't have to be someone who sits in front of a computer 247. Excuse. Hey, everyone. I'm Basil, and in this class, you're going to learn everything you need to get up and running with Python. I started programming several years ago, and I've been teaching it for more than three years now. It was very rewarding for me to see how the computer could do all the work with just a few lines of code. And soon I realized the massive potential of Python, since we're heading into completely computerized world where programmers are in very high demand. If you really want to get into programming, but don't know where to start, this course was made with you in mind. It's composed of a series of very clear and concise videos that will cover all the fundamental topics of Python. These include downloading Python, printing texts, using math and Python, variables, inputting data, if else statements, while loops, functions, as well as several checkpoints along the course to check your understanding. So what are we mating for? Let's jump right into it. 2. Python Overview: Stats for Nerds: Now before we get into the actual programming, I find it very important that you know what exactly Python is and the key features and properties of this amazing programming language. There are three main points that I want you to know. First of all, is that Python is a high level scripting language that can be used for a wide variety of interests related tasks, system administration, and texts processing. Second of all, I want you to know that Python is an interpreted language. Interpreted languages do not need to be compiled to run. This means the programmer could quickly change the code and then quickly see the results. Third of all, I want you to know that Python is an open source programming language. This means that it's available for everyone, that it is easy to read and powerful. At the same time. 3. Downloading Python: Okay, So downloading Python is really easy. You only have to go to your search engine. In the search box you're going to type Python download. There you go. Then you're gonna get a bunch of results. But the safest and most reliable website to download Python prompt is SURPRISE SURPRISE! the Python website itself! You're going to click that. And then here I'm using Windows, so I just have to click this yellow button. because here it says "you can download the latest version for Windows" if you're using another operating system, you can just go ahead and click on the macOS, any other, Linux. And if you want to see the previous releases or any other releases, you can go here. I'll releases and depending on your operating system, you'll choose Windows, macOS, other platforms. But it's as simple as clicking this yellow button. So I'm going to click that and it downloads here in the corner. All right, Once it's done, you can go to click that great and then you click Install. Now. You click Yes. Now I'm not sure if this appeared on the screencast. But what happened was I got a notification from Windows that says if I want to allow this to download and I just clicked yes. So if you see that, it's a 100% safe. Now this could take a little bit of time, okay So you just gotta be patient until the bar reaches the end. Then it will be on your computer. Still initializing. Okay, there we go. We have some progress. Now this only usually takes about a few minutes. More or less of course. Okay, Almost done. Okay, set up was successful, you're done. You just click Close. And there you go. You type Python here. So we want this one, the IDLE, this is the one we're working on. I'm gonna double-click that. And there you go. This is Python. You have Python on your device. 4. Displaying Text : The first and foremost thing to learn in Python is definitely how to display text. But we have to stop here for a moment and ask ourselves what exactly is text in Python? Well, text is very simply any character. It could be an uppercase letter, lowercase letter, a number, or symbol that is in-between two inverted commas, and they have to be in-between two inverted commas. Texts in Python is called a string and it's shortened to STR. And it is displayed using the print function. Now that you know the basics, let's go see this in practice. Okay, so since this is the first ever program code for you, I'd like to walk you through the process step-by-step. So when you open Python, you're gonna be in the IDLE shell, and this is essentially where the results of your code will appear. And when you want to write the code, you have to open a new file. So file, new file. And there you go. This is where you write your code. Our first code will be displaying text. You want to print a message. And to do that, we're going to use the print function, which is 'print' in lowercase and two parentheses. And now whatever you want to print, you have to write between these two parenthesis. So if I want to print a string, I just have to put two quotation marks because this is the structure of a string. And then here I'm going write any sentence. So let's say one kilogram of mangoes. costs $3. Okay? So I chose the sentence because it has numbers like 1 and 3. It has a symbol, the dollar sign, and it has an uppercase letter, even though it's grammatically incorrect, and also lowercase letters. Now, this is just to show you that a string accepts any type of character. And okay, so this is your first type of program code. If you run this, you have to go to Run, Run Module. You have to save it. Let's go ahead and save that, "example". And there you go in the shell, we have displayed the text One kilogram of mango costs $3. Congratulations, this is your first line of code. Now I want to teach you a bonus skill, and this skill is converting text. To do that, I have to go back to our file. And instead of this string, I'm going to have a one word string, which is banana. Banana for example. And I'm going to run that. Okay? And as you can see, I have banana in lowercase. But then say, I changed my mind and I want it to be in uppercase instead of removing it and then, retyping it in uppercase. But I can do is dot upper right there. Run, Run module. Okay? We get banana in uppercase. You can do the exact opposite. We can have it in upper case here. banana. Then use the dot lower function, dot lower. Run, Run module. Okay? There you go. We have banana in uppercase here and then lowercase in the shell. And one last thing is you can have, for example, banana, then you can capitalize just the first letter. So we only want the B capitalized. We got to do dot capitalize, wonderful, now run, run module. Okay? We have just the B capitalised and the rest is lowercase. Yeah, that's it. This is printing text. 5. Using Numbers in Python: Math can get repetitive. Those numbers can get confusing. and those decimal points really got on my nerves. However, what if I told you that Python offers a solution for this? All you have to do is write the correct code. And this is exactly what we're gonna be learning today. But before we do that, I have to introduce you to two key concepts when it comes to numbers. So the first key concept is that there are two types of numbers in Python. The first one is integers, and you may be familiar with those from Math. Integers or any whole numbers. They could be positive, negative, or 0. And Python recognizes integers as 'int'. And if you type that in, it turns purple, indicating that it is built in and recognized. The second type of number in Python it is called a float. A float very simply is any number that has a decimal point regardless of what's before or after the decimal point. And these can be positive or negative. Now be careful, this can get really tricky. For example, this 15 and this 15 have the exact same numerical value. However, since this one has decimal point, Python deals with it as it as a float and deals with this one as an integer. Anyways, floats are built-in and recognized by Python as 'float'. There is no shortening for us, and of course that turns purple. Now the second important thing you have to know is that numbers are not strings. You do not put them into inverted commas because they are completely different datatypes. To compare, strings are a set of characters that have no numerical value, while numbers have a value that Python recognizes. To make things more clear. Let's think of numbers as figures that represent units. For example, five represents five units, three represents three units and 7.8 represents seven units and eight-tenths of a unit and so on and so forth. So whenever you use numbers in a situation that demands a numerical value, you do not put them into inverted commas because if you do, they will lose this numerical value. And thus they'll be ineligible for mathematical calculation. Now, don't get me wrong. This does not mean that you couldn't or shouldn't use numbers and strings. You can, and it's perfectly fine, just like I did in the previous lesson. However, what I do mean is that if you want this number to hold a numerical value, if you want to use it in a calculation, you have to use it as an integer or a float rather than as a string. Confused? don't worry, you'll understand everything in practice. Okay, so let's start really simple by printing some integers. So 'print', lets have seven, for example. Let's print a negative integer like minus 12. Let's print 0 because 0 is also an integer so you run, run module. Okay? And there we have our integers. Okay, Very nice. Now let's have some floats. So 7.98, minus 12.45, 0.26 for example. Let's run this, run module. Okay, there we have our floats. Now what I want from you now is to experiment with the numbers, mess around with them, just like try some very big numbers, very small numbers, integers and floats. And I find it very important that you know how to tell them apart, that you know which is an integer and which is a float. So go ahead and start printing some numbers. And this is not really how we use numbers in Python. We use them in mathematical calculations, which is what we're gonna be getting into soon. But for now I have to make sure that you're familiar with the numbers. So go ahead and start. And remember, do not put the quotation marks because we're using them as numbers and not as streams. Now once you're very comfortable with using numbers as both integers and floats, you can go ahead and move on to using them in calculations. Now today we're gonna be talking about six types of operations. And these are addition, subtraction, multiplication, division. Powers or indices and modulus. Now let's start with the easiest one which is addition. So print and two brackets and I'm going to add two numbers like 5 and 9 for example. You run that. Okay. Awesome. We got 14. Now, remember when I told you how you can't use them as strings, let's see what happens if I put two quotation marks and turn it into a string. run, run module, okay Yeah, you get five plus nine, just deals with them as characters and sticks them together. It does not do the actual operation because the number is lost their mathematical value. Now let's go ahead and have a look at subtraction. What I have to do is print two brackets. Then here I'm going to have like nine minus six. I should get three. The minus sign is the hyphen. So we run, run module. Okay You get three. Awesome. Let's have another example where the first number three, the second is six, so that we get a negative number. We get negative three. Very nice. Subtraction is as simple as this. Now let's move on to multiplication. Multiplication is also very simple. Print. We have nine times six. The multiplication sign is the asterisk. And run, run module. Okay, we get 54. Let's have another one. For example, 4.8 times six. run, run module, okay Now as you can see, you can, you can try both floats and integers. Okay, So now let's move on to division, go ahead and write print again. And the division sign is the forward slash. So for example, we have 72 divided by 9. we should get 8 So we run, run module. Okay? Awesome, You have eight. Let's try another one. We have, for example, 35 divided by seven. Okay We get five. It's very easy, it's very simple. Now let's move on to powers or indices, for those of you who don't know what this is. For example, two to the power of three means two multiplied by itself three times, so that's two times two times two, which equals eight. To do that, we're going to print two. And to raise a number to the power of another number, you put two asterisks and three. This means two to the power of three. Run, run module. We should get eight. Awesome. Now let's try other numbers. So we get like a crazy large number. Seven to the power 473 run, run module. Okay, awesome. You could just have fun with this, okay? He could drive very small numbers, very big numbers, etc, until we got the hang of it. Now the last mathematical operation for this lesson is going to be modulus. And to illustrate this, I'm going to use an example because this could be new to some of you. So print, two brackets, five modulus two, so modulus is the percentage sign. So five modulus two five percentage sign too. and You read this as five mod two. And what Python does is it takes the five, divides it by the two, and then it spits out the remainder. So five divided by two is two, remainder one. So when I run, I should get one. Let's try another one. Let's try 17 divided by five. For example. This should be three, remainder two. So I should get 2. Now one very, very important note is that Python uses the order of operation. What I mean is if I do print four plus five times seven, it's going to multiply five by 7 first because it prioritizes multiplication over addition. So five times seven is 35, and then it's going to add the four. So we're gonna get 39 run, run module. Okay, Great. Now if you want to add the four and the 5 first and then multiply the whole thing by seven, you have to add brackets. This is how we prioritize certain operations over others. So this way we have four plus five, which is nine, and then nine times seven. This gives us 63 run module, okay 63. You see the addition of the brackets change the number from 39 to 63. It's very simple, it's very easy. Just pay attention to that and everything will go Amazing. 6. Bonus Skills: Numbers in Python: Once you've mastered the basics, it's always a good idea to step things up a bit and challenge yourself. So how about you go ahead and check these bonus skills? Now, nearly all programmers use numbers at some point in their code. So I'm going to walk you through the bonus skills and awesome functions that you can use when dealing with numbers, since they form a huge part of Python. Now, the first one is to classify if a number is an integer or a float. And do this, I'm gonna use print. The function we're going to use is the type function. So type in lowercase and two parentheses. It turns purple because it's a built-in function. In here. I'm going to have a float like 4.9 for example, run molecule. You see it's classified 4.9 as a float. So let's try nine for example, which is an integer. Okay? We get to class int. So it tells us that this is an integer. Now let me show you what I meant with the example of 15 at 15.0 in the previous lesson. So 15 without a decimal point, run, run module. Okay? This is an integer. Now if I do 15.0, the numerical value is still 15, but it has a decimal point. now so run run module. It is now a float. At some point when you're writing your program, you may find it useful to know how to convert numbers from floats to integers and vice versa. Now to do that we're going to use the print function first to visualize the results. Then here I'm going to do INT float in here like 15.0. Okay? Now what this does is it takes 15.0 and converts it into an integer, and then it prints the result, it shows us the integer version of 15.0 There you go, It prints 15. If you want to do the opposite, you want to convert an integer into a float. you use Float. Let's have 15, for example. Run module, okay? And you get 15.0, which is float version of 15. And you can find this especially useful when dealing in physics, for example, with quantity tables where you have to be consistent with a number of significant figures. So you can't have both floats and integers in the same table. You can either have all floats or all integers. So we're going to have to use this and convert either to either. You can also convert a number to a string. So print STR, you type in the number like For example, 16. Run, run module. Okay? Now there is no visible difference here. But what happens is this 16 now does not have numerical value. It just lost its numerical value and you can no longer use it in calculations. However, you can use it in a sentence. So this is especially useful when you're going to use a number alongside a string or alongside a sentence. Now to show you that this has lost this numerical value, i'm gonna try to add that to say 14. Run module. Okay? It prints out an error message because it's not right, it's not INT. Now there's another very useful function that gives you the absolute value of a number. If you don't know what that is, think of it as the distance of a number from 0. For example, five is five units away from 0. Minus five is also five units away from 0. So essentially to find the absolute value of a number, you just remove the negative sign. If it was negative and if it was positive, you just leave it as it is. So to do that, print the abs function. and let's have. For example, negative 93. Let me run this run module. We get 93 because this is the absolute value of negative 93. It is the distance away from 0. That negative 93 is, it is very simple, very easy. You might not use this now, but you certainly will in the future. And we have another function, which is the power function. So pow, to parentheses And this is one of the functions that allows you to pass it the two pieces of information. So for example, 2 and 3, okay? And what this does is it raises two to the power of three. It is the exact same. As doing this. So print 2**3, we have the exact same value. Let's see that, they both give us eight. It's very nice to know both of them. Now we have two other functions to which you can pass two pieces of information. These are the max and Min functions. Let's start with max. You may simply print then max, two parentheses. And in here you're going to have two numbers like 13 and 9 And what Python is going to do is it's going to compare 13 and 9. Then it's going to print the larger number. So run the module. Okay, we got 13 because 13 is greater than nine. And then there is the Min function. So min 13 and 9 run, run module. This is going to give us the smaller number. Gives us nine. Very simple, very easy. Now the last bonus skill I want to teach you today is going to be how to round numbers using the round function, print and round, two parentheses. Now what happens here is whichever number you type here, like 4.9. Now this rounds to 5 them. So if I run, run module, okay, it gives us five. And then let's say I want to round it down to like 4.2. This should round to four. Run, run module, okay? It rounds to four. So what this function does is it basically rounds the number to the nearest whole number. 7. Checkpoint: Numbers in Python: You are doing great so far. Are You Up For a Checkpoint, let's check your understanding with this very simple exercise. In this exercise, you will write a very simple yet very useful line of code that will help us convert between degrees Celsius and degrees Fahrenheit. So first you have to go to a search engine to find a formula for that. And I found this one, which is degrees Celsius times nine over five plus 32 gives us the degrees in Fahrenheit. So now that you have the formula, I want you to write a code that will convert 20 degrees Celsius to degrees Fahrenheit. Then I want you to round that answer to the nearest whole number. So you're going to have to use the round function. I want you to try this yourself. So go ahead and pause the video before the answer appears in 321. Now the key to writing this very simple line of code is to substitute 20 into the formula that converts degrees Celsius to degrees Fahrenheit. Because we want to convert 20 degrees Celsius to the equivalents in degrees Fahrenheit. So very simply we put 20 inside the formula. So 20 multiplied by nine divided by five and then plus 32. And notice here how I did not use brackets because multiplication and division are already prioritized over addition, so there's no need to add brackets. Then we want to round our answer because the answer has to be to the nearest whole number. So round function. right there. And finally we have to add the print function. So there are Python prints the answer. There you go. So what happens here is it takes 20 degrees Celsius. It puts it inside the formula right there and calculates the number of degrees in Fahrenheit, the rounds that answer to the nearest whole number. And finally, it displays the result in the shell because we have the print function. So run, run module. Okay. Yeah, Let's go ahead and check that in our research engine, you have 20 Celsius equals 68 degrees Fahrenheit. Awesome job. 8. Variables: Using variables is a very foundational aspect of programming that you're really going to want to know and master. And here's why. Because in Python you're going to be using a lot of data. This data can sometimes be hard to manage and overwhelming. This is where variables come in to make things much easier. Variable is the location in memory in which you can temporarily store text or numbers. You can think of it as an empty box in which you can store anything you like. Simple, right? Wonderful. Let's jump see it in practice. So I'm going to start by showing you the structure of a variable. The structure is very simple. It's basically the name of the variable, the equal sign and then its value. Let's call a variable "a", equal sign, followed by lion, which is the value of a. So basically what this means is wherever a occurs in the program, we're referring to a lion. And the name is a, there is an equal sign and its values the string lion. Let's have some more variables like b equals nine. For example. Secret equals I equals I ate the last cookie 00:01:15.710 --> 00:01:16.670 let's have Number equals 36. lets Have my pet. Equals bunny. Finally, let's have anwer equals true. Now there's a few things I have to point out here. First of all, the structure of a variable is name, equal sign, value. And the name could be one letter like a or b. It could be one word like secret or number or answer. It could be a phrase like my pet. However, notice here that you can't have spaces in the name of a variable. So my pet was separated by an underscore and not by a space because you can't have a space in the name of a variable. It's either an underscore or just like no spaces, which I do not recommend. Go ahead and add that underscore. And that's it for the names, the equal sign is pretty standard. And finally, we have the value. Now, variables can take three types of values. They can take a string like lion, I ate the last cookie and bunny. And it could also take numbers like 9 and 36. And finally, we can take a Boolean value. Now, a Boolean value is basically either true or false. It's only these two values, it cannot take any other two values. And you may not be very familiar with them in our day-to-day interactions and our day-to-day life. However, in programming, we nearly use them all the time. They're very important. Just to illustrate what exactly they are. For example, let's say if I asked you, Are you left-handed? Now If you are left-handed, you say true, Viagra attended, and if you're not, you're gonna go false. I'm right-handed, but there's no other options are either left-handed or right-handed. It's either true or false. There is no other option. So this is basically how booleans work. Let's start with a very basic exercise, which is simply to print variables. So I'm going to have w equals popcorn, I'm also going to have m equals 92. So if I want to print the word popcorn, I can simply do this. Print w. What Python does here is it comes and it sees that it has to print W. It revises the code. So W equals popcorn. So it's going to print popcorn. So run module, as you can see it printed popcorn. Let's print m. For example. Run, run module. You have 92. So now let's have an example to see how we use variables in Python. Now, I'm going to start by writing a sentence. For example, I have a pet. bunny. My bunny is called picasso. And I've never seen this cute. Okay, let's try this. And there we have our sentence. Now. Let us say that four years later this morning grew up and became a rabbit. I'm going to have to change the sentence and replace bunny, rabbit every time it occurs. And let's try and do that. Okay? Yeah, rabbit. Rabbit. And we also have a rabbit over there. Now this was not very fun and I could've made a lot of mistakes. I could have missed one of the bunnies, I could have misspelled rabbit. And let alone It took a lot of time and effort. Imagine having to code that's thousands of lines long. Were we mentioned bunny several 100 times. And you have to change every single one of those into rabbit. This is not very doable because you won't have enough time and you will make a lot of mistakes. So this is where variables come in. To show you that, I'm going to create a variable, let's call that pet, for example, equals bunny, okay? what I can do here is remove the sentence. I'm going to add a new one. So let's do i have a pet. Then here I'm going to interrupt the sentence by closing the string, add a new comma, the name of the variable. Another comma, then reopening the sentence. Now what happens here is when Python starts to read the print function, it types in, I have a pet. Then it sees this one, it sees pets. So it's going to go ahead and look for pet in the code and it's going to find that it's equal to bunny. It's going to insert bunny over here. And that is going to continue. One last thing. There are no spaces over here because Python automatically inserts the space. So I have a pet bunny. Um, so my, buny, then we're going to close that. Again. comma, pet, comma reopen is called picasso. It's called Picasso. I've never seen a Now, we close, comma. add a comma, and reopen. this cute. and close. Okay. I know this was a bit harder than just typing in bunny, but let's see what happens on a run, run module. Okay? So I have a pet bunny. My buddy is called Picasso. I've never seen a bunny of this cute. It just put bunny, right where I put that. Wherever I inserted this variable, it replaced it with bunny. Now let's say that four years later it did grow up. What I do is I just replaced bunny over here with rabbit. Once in the variable. When I run, I have a pet rabbit, my rabbits, I've never seen a rabbit. It's replaced bunny with rabbits every time in the sentence. Now this was much easier than looking for bunny every time it occurs in a sentence and just replacing it with rabbits. Look, I didn't make any mistakes because they only have to write it once. I couldn't have missed one because variables are already there. And so this makes life much easier for a programmer. So far we've seen variables that represent strings, but we haven't seen variables that represent numbers. So I'm gonna go ahead and start with that. And to illustrate this, I'm going to use an algorithm that I completely made up. So let's do print the result of, let's say three plus five minus three times five plus three to the power of five. Okay, let's try this module, okay? The answer is 236. Then let's say that I just made a mistake and it was supposed to be seven instead of five. So I'm gonna go ahead and change five to seven every time I see five. And another seven here. Run, run module. Okay? I got to 2176. The answers are very different. And you see, this one is just like a few characters long. This algorithm is a very small algorithm compared to the others that you might use in your programming careers that could be lines long. And so it's not very doable to just go through all the lines and check for fives and then replacing them with sevens. And you wouldn't know which 5s should already be there, in which five should be replaced, the sevens, because you know, not all of the fives could have to be replaced with a seven. And this could have some confusion with it. So we can do is add some variable. Now I'm going to create two variables. These are going to be N1. Let me set that to be equal to three. And N2, which is going to be equal to five. Then here I'm going to replace those. Instead of using actual values, I'm going to use the variables inside. So N1 and two. And one. Oops, I'm sorry. It should be N two to one So here the algorithm used the values of 3,5 and so we got to 236. And let's say I thought that this was wrong and it has to be seven. I just do this and this. We change it with the click of a button. Run, run module, okay? And we got the correct answer. and what you can also do is have this algorithm as a variable. Let's do for example, a equals. Say that we made a mistake in the algorithm itself. Let's say this shouldn't be a negative sign, this should be a plus sign. We just changed it here. Then we can say print a run, run module. Okay, this is the result when we, when we use a positive sign over here. And so basically, basically you can have it as a rule of thumb whenever you're going to repeat a value more than once. And this value could potentially change. You use a variable, or for example, wherever you have a very long sentence or very long string that you don't want to keep typing again and again and again. You can just replace it with a very short variable name. Just add that instead of repeating and repeating and repeating and typing it in and typing it when it's very long. It's gonna be a pain in the neck. So you can just make things much easier by using variables. 9. Bonus Skills: Variables: Once you've mastered the basics, it's always a good idea to step things up a bit and challenge yourself. So how about you go ahead and check these bonus skills. The bonus skills for this class will revolve around variables that represent strings. So let's go ahead and create one. For example, deserts equals caring. Wonderful. So let's print dessert first. Desert. I'll do. Okay. Wonderful. We have our variable right there. Now the first thing we can do is we can determine how long this variable is. If I'm going to know how many characters there are in the phrase carrot cake. It can be very useful sometimes. I can just get the length of this variable. To do that, all I have to do is use the length function, which is Len and two brackets. So if we run, run module, okay, we get 110. This is the number of characters there are in the phrase carrot cake. So let's go ahead and tell them real quick. So we have 123456. The space is a character, so 7891011, we have 11 characters in this string. Now sometimes the string can be very, very long that you can count it. So you can just use the length function. Now sometimes it can be very useful to grab just one character, just one letter from this whole phrase. Let's say I want the first one or the last one, or just any character in there. I can identify each character by its index. An index is basically the position that Python gives to a character inside this phrase. And Python starts counting from 0. So let me show you this. Starts counting like this. So the first one, mix of 0, then 1234 and so on and so forth. If I want to grab the first letter, I'm going to grab v letter with index equals 0. What I'm gonna do is this friend's desert, the two square brackets and then the index of the character I want to print, which is 0. In this case, I want to get C because it's the first letter over there. Also don't leave just random numbers hanging in there because they might ruin your code. We get C. Very nice. Let's do the second one which has index equals one molecule. Okay? You get a, let's try the eighth one for example. I'll do another. A lovely coincidence. Now, when I did h over here, I did not want the eight character. I want the index of eight, which is basically the seventh character. Now we can do the exact opposite using the index function. Now what this does is it's going to take the character that we give it, and it's going to give us its index. And it's the exact opposite of what we just did. What we did was we gave it the index and it gave us back the character. So now we want to give it the character that's gonna give us back the index. Let's try this using the index functions of print. Desert dot, index, two brackets. Then say you want to grab the E. Now, E is the last one. So it's going to have the tenth index because it's in position 11. So it starts from 0. So we're going to have ten run, run module. Okay? Awesome, we get ten. Now finally, we also have a very simple and very useful function that is called the Replace function. And I think the name explains itself. So basically what this does is it's going to take one word or one character from the phrase, and it's going to replace it with another word or another character. Let's try that. So print. And then we're gonna do desert Triple P S over there. Okay, so deserts dot replace. And then two brackets in here. And we're going to cost two pieces of information, that original world and the new words. So the original word is carrot, and the new word, for example, is chocolate. This one's gonna do is it's going to find carrots and this drink, and it's going to replace it with chocolate. Run, run module. Okay? We get chocolate cake. And it also works with single letters. But it's all very relevant here. So if I want to change all the ACEs, we can do this run, run module. We get carrot cake, k, whatever that is. So this is just for fun. You might sometimes use it, but you're never going to have to change like all the A's and two 0s because, you know, you must have worked with an egg, right? 10. Inputting Data: In Buddhism, integral and human computer communication. Because if you don't feed the computer any data, it won't give you any information, and thus, you won't get a result. And this is y input is one of the most essential and also easiest skills learned in Python. Now, what do you do? An input is basically, we're going to ask the user for some information. We're going to ask them to give us some data. And then we're going to take this data and assign it to a variable. So we're going to store this data inside a variable. Now, what's the difference between this variable and the variables we use to talk about in the previous lessons. Well, basically this variable has a value that the user decides. The user can choose anything to swear inside this variable. Meanwhile, the variables we talked about earlier, how the predefined value that is set by the programmer and the user has no control over it. Awesome, Let's go see you got in practice. Now the basic structure of inputs is as easy as this, but in two parentheses or two graphics. However, there isn't much information we can get from this. So when the user is using the program, there's no prompt or no question that asks him to enter information. He has no idea what to ensure. And so we can type in a prompt over here. So the prompt is string. It says, for example, Enter, hey, you're going to want to leave a space there so that there's a space between what they enter your question. And then we already said that we're going to assign this input. We're going to assign this data into a variable. So let's go ahead and add a variable there. Let's call the inputs name equals. So what this does is it's going to take the name of the user to enter their name. Then it's going to store it inside the variable name. Now let's print this. Let's put a message. I'm sorry. Let's print a message that it will welcome the user. So print Hello. Better remember this a comma. We're going to enter the variable. And let's do an exclamation mark. Prime. Python. Python 3.7.43.4. Nice to meet you. Wonderful. Now let's run this and see what happens. So here the program asks us to enter our name, enter your o, nor any spelling mistakes. It's okay. Okay, so enter your name. So my name is misused and then enter because hello bits you write Python 3.084. Nice to meet you, nice to meet you too, 5M. Now in the previous example, we saw input being used as a strength because we have to enter our name and name is sets and so it's trained. But we sometimes have to enter numbers that have to be used in the calculation. And let's illustrate this with an example. So input, enter your age. Now, age is an integer and convert this input into an integer. We're going to have to do this. And t in brackets. It's very simple, it's very easy because input, enter your age as it is. This is a string. But when we add the INT, it converts the value that the user enters from a string into an integer. And of course you have to store this value inside a variable. Let's call that h n equal sign. I'm going to add another variable very similar to this. I'm going to call that current here. I just copied and pasted that. So that's good. Change up the names. Print here, enter here. We're going to calculate the year that the user was born in Northern to do this by using simple mouth, which is the current year minus his or her age. And so here, the values that the user input will be used in the calculation. So we have to be integers or floats. But since age in years are most commonly uses integers where we're going to use the INT function. So let's go ahead and do this. So a year is equal to current year minus the H. And we're going to print welcome message here. It's gonna say you were born and then comma here, your score. One from this. So run, run module, okay. So enter your age. Let's say that I'm 29. Current year is 2022. I was born in 1993. Let's try another one, run module. So enter your age, Sam, 55. And the current year is 22. I was born in 1967. Wonderful. And sometimes there are situations where you have to use an input that is a float, for example, with temperature. Now, the temperature can say, could decimal values like thirty-seven point five. So I'm gonna go ahead and create a variable called temp out. As we come to trial type, that's going to be equal to float. You put two brackets and Enter the temperature outside. I'm going to create a variable called temperature inside. So this is going to be equal to the temperature outside minus ten degrees. So this is just my own sort of calculation. You could use whatever you want, equal to ten minus ten. Now I'm going to print inside. So the temperature inside is ten minus 1010. Out is an input that the user gives us and it can take it as small values. Run the module. Okay, Wonderful. So the temperature outside, let's say it's 29.8. We temperature inside is ten degrees less than that, and it is 19.8. And this is basically how you use inputs as both integers, floats, and strings. 11. Checkpoint: Creating Mad Libs: You are doing great so far. For checkpoint. Let's check your understanding with this very simple exercise. Now for this checkpoint, I want you to write a program code for the game Mad Libs. Now, here's the general sample that I used. I made that up. So basically I'm going to start to go through the welcome message. So hey, they're always playing a fun game. Then I'm going to have, this game is called Mad Libs. Here's how it works. And then I'm going to explain how the game works. So I'm basically just printing some instructions over here, like welcome message and then some instructions. So my whole prompt you to enter REM words, the different categories, and placed them in a random sentence of a story. And his work substitutions have humorous effect when the resulting story is then read out loud. Let's start. So hope that's clear for you. And when we start to play the game asks us to enter now. And so I'm going to enter a sofa example. Enter number. Let's go with 15. Enter a color, pink. Name of a celebrity to Lipa. Now when we enter, you get these very random sentences. So my best friends is sofa. 15 is my lucky number. And dual EPA likes pink bears. This is what makes it very funny and has no meaning at all. It's just very random. And you can try all sorts of different combinations. But for the first time for this checkpoints, you can just try out those that are used. And it would be wonderful if you could try that yourself. So go ahead and pause the video before the solution appears in 321. Now here's the code that I use for writing this Madeline. So it's actually very simple and it looks very long, but it's very simple. So let's have this side-by-side with the result. So first of all, we have a printf function that displays the welcome message right there. This is very easy and very simple. When you have this blank space, you have there's like empty line. To achieve this, you only have to do the print and then to empty quotation marks. So there's nothing between those. And this shows us that we want a blank space right there. Then we have a new message which is right there. And then the instructions, you can just take those from your search engine or any books that has methods in it. Or you can just not have them in at all. But I add them just in case some of you didn't know what amount with this. So you can just type in your own instructions for each and just type in anything else. These are just simple print function so that the display the user sees is more friendly. And then this is the juice here. It asks us to enter now a number of color and the name of a celebrity. And since we're asking the user to enter some information, to enter some data, we have to use the inputs. So then you have a variable, input, variable here because this is a number and use the INT I converted it into an integer. But again, we have variable input, variable inputs. So every time we took a piece of information from the user, we stored it inside a variable. And then very simply, we printed some sentences. We've got a new line here, force printed some sentences, and we entered the variables, the values that the user gave us. So we entered the input into our sentences because they are now assigned to variables and those variables into sentences. And so very simply, we print some print functions and then some variables wherever you want to insert them. And this is very simply how you write the code or a mountain. Now what I want you to do is to go ahead and experiments with all the different sorts of categories in words so that you produce lots and lots of different Mad Libs and then show them to your friends and family. And I guarantee you, you will get amazing reactions. 12. If/Else Statements: We all face situations where we have to make some decisions. And then based on these decisions, we determine our next steps. Now very similar situations, right? Some programming where we have to make some decisions, then based on these decisions, we can run certain lines of code. So basically, if else statements decide the direction of flow of code execution. So if some conditions are true, let's say that these conditions were met by the program. Then Python will take a specific course of action and it will perform a specific task. Meanwhile, these conditions were false or if they were not met, then Python will take another course of action and it will have another task before. This is essentially what makes your computer a lot smarter. Now that you know what it is, Let's go ahead and see that in practice. Now let's start with a very basic decision to make so that we can show you how the if-else statement works. Now, we're going to have a program that decides whether a student passes or fails. It's gonna do that by comparing their grade out of 100 points. So let's say that they sit a test out of a 100 points. And we're going to compare their agreement that tests to the passing rate and the passenger is gonna be 15 points. Now first we have to get the students grade, and we're going to have to do that by using the input. So grade equals hi In D. Input. Enter your grade. 100. Wonderful. And then we're going to proceed and type in the if else statement to make the decision. Now, the if else statement is composed of two parts. The first one is the if statement and the second one is the else statement. Now the if statements basically saves the condition. So if and then our condition two paths is this grade is greater than 50. So if grade is greater than or equal to 50, then we have a colon which indicates the end of the if statement. Then we enter and we have an automatic indent. Now this is because we have to differentiate between the code that's executed within the if statement and the code that's outside the if statement. So anything that is indented below the if statement is going to be a consequence of this if statement. So what is the consequence of the grade being graders and 50? The actual we're going to take is we're going to tell them that they pass. So print Graphs. Now here, if they don't pass, they fail. And this is because there are only two options, passing and failing, and there isn't any other option. And so basically, if the grade is not greater than or equal to 50, we're left with an option which is the grade is less than 50. And so we can have the else statement. Remember to get back to the beginning of the line because we're no longer inside the if statement. Writing the other part of the if else statement, which is the else statement, then colon cancer. And we have another event for the else statement. Now I want you to notice how I didn't have anything after the else. So basically no condition, no comparison, nothing. It's just else and a colon. And this is because else basically wraps up everything that wasn't in the if. So, anything that does not satisfy the condition of the if it goes into the else and that's it. So we have an indented over there. And let's do else was print a string so you fail. And this is very basically an if else statements. Now let's run this. Okay, So here's how it's going to work. It's going to ask us for the grade out of 100 points. So let's how I type in 95. Okay, So now what it's gonna do is it's going to take the 95, it's going to compare it with the 50. Is it greater than or equal to 15? Yes, it is greater than 50. So it's going to print congrats, you pass loops. We lost that. No probability. So 95, hang rats, you pass. And then let's say that we have another student that scored a Thirty-five. Thirty-five. Now what's going to happen here? This is going to take 35 and compare it with the 50. Is it greater than or equal to 15? No, it's not. So it's going to move on to the else statement. Else tells us that if the condition in the if statement was not met, then you can proceed and do the consequence for the else statement. It's going to type in you fail. Let's go see that. Show Enter. It says you fail. This is very simply how an if else statement works. Now there's a few things I have to comment on over here. Let's start from the beginning. You realized that I use I and t. I converted the input into an integer. And this is because here we compared it to a number. And mathematical comparison is considered an operation. It has to be either an integer or a float. Now, depending on the nature of the grid, if it takes decimal values, you can just go ahead and write float in there. But we took two integers over here because it also works. So, yeah, Then we're going to have, if it turns orange, else turns orange because these are built in. And when you're done with the condition, you put a colon over here. You have a colon after the else. This is the basic structure. Now, as for the condition, here we use an integer value and we compare it with another number. Now here are the mathematical comparison operations. These are greater than, less than, greater than or equal to, less than or equal to equals. And it's not just one equal sign, it's two equal times. Remember this? And we also have not equals. So this just means not equals, greater than, less than, it's just not equals. These are the main operations we're going to use. So again, greater than, less than, greater than or equal to, less than or equal to equals, equals. This is just equal to n. Exclamation mark equals means not equal to. Finally, you have to pay attention to the indenting levels. So basically, every action you are going to take that follows the if statement. So for example, if this condition was true and you have to take a certain action, you have to indent. But then when you're done with those and when you want to say it's the other part of the segment which is the else. You can go ahead and go back to the main line level. Then when you're done with the else, you're going to indent again to show that this one follows on from the else statement. Now in the previous example, we've seen how if else statements can make decisions by comparing numerical values. But we can also use if else statements with Boolean values. Now let's see how this works. So let's have our first Boolean value. So write equals true. Now to create an if else statements here, we're going to have to do if, then write the name of the variable. So if right-handed. And what this basically means is if right-handed, if this variable has the value of true, execute the following code, and enter it automatically indents. Let's have print RH. This means Right-handed, Okay? And else, so this means that if right-handed was not true too, if this was false, we're going to print left handed. And print h bar h is right-handed and LH is left-handed. Let's run and see what we get. We get our h right-handed because initially this was set to be true. So right-handed was true initially. And the if statement has a condition that right-handed is true. And so he got RH. Now, if we change this to false, false. Run, run module, okay? It prints LH left-handed because this condition is no longer true. So we have to move on to the else statement and print out h. Now sometimes you might have more than one condition. So let's set that to true. Let's create another condition called male. I'm going to set that also equal to true. Since here we have two factors. We can make four combinations. I'm going to print them down below. So these are RH mail or right-handed male, a left-handed male, a right-handed female, and going left-handed female. Now, sir, I just want to grab one of these categories. Can print a message for them. Say I just want to grab the first category right-handed males. Now, to do this, I need to have right-handed and male both equal to true. So it has to be both a male and right-handed. But how do I insert this to the if statement? Now, if he wants both conditions to be true, we can use the end. It is built in and therefore turns orange when we print it in. And then we're going to have to add the name of the second factor that we have. So if this guy is right-handed and a male, we're going to print right handed male parent molecule. Okay? Always remember to remove unnecessary pieces of code which weren't really called. These were just my notes. We've got RH male or right-handed male. Now here we might face a small problem with the else statement. And here's why. So as we said, we have four options. Right kinda male, left-handed male, right-handed female, and left-handed female. And all the if statement will print this message only to the right-handed males. And so the else statement will print this message to every other category, left-handed males, right-handed females, and left-handed females. However, we can't just rule out one of those and send a message to specifically just one of those categories. Because the else is very general and it simply means anything that was not in the, if we printed in the US regardless of what's over here. So how do we fix this? How do I introduce another condition to the if-else statement so that I can rule out different categories. I can do this using the elif statements. This is simply, you live and the liver is short for else-if. And then you can write their conditions. So we're going to have right-handed female as example. So a right-handed female is true for right-handed but false for male. So let's go ahead and change that to false. Then what we can do here is else, if so, if it wasn't for right-handed or male gender, we're going to move on to the IO statements and we're going to have right-handed. And not. Now not male means that male is false and it is false. So since both of these conditions are met, right? Tenant is true and not male is true. Since mill is false, then we can print the message only to those that are not males, but at the same time are right handed and left have right-handed. Let's run this. Again. Never leave just cranium texts inside. We got right-handed female. This is because right-handed is true, but male is false. So this must be a female who's right-handed. And now we can add another eel of seconds. Or you left handed males. Else, if not, write Android, which means left-handed and male. Let's print left-handed. Now let's change this up. So for this one to be true, we want it to be a left-handed. Right-handed should be false. I'm going to change this to false. And male is true. So we're going to change this to true. Let's run, run module. Okay. We got left-handed male because this is how Python reads through the code. If right-handed and male, are both of these true? No, they're not. So it skips the if statement and moves on to the first deal if statement. Now, is it right-handed and not a male? So israeli tend to true and false? No, it's the exact opposite. It moves on to the other gill if statement. Now, is it not right-handed? Right-handed is false. That's true. And male. So males should be true, which is right over here. So we met this condition right there. So it's going to print left handed male. And now the only other option left is going to be a left-handed female. So we can just continue with the else statement, then write LH female. Now, let's have both of these to be false. Can print left-handed female. So now when we run this module, okay, we get a left-handed female. In the previous example, we've seen the end and this one was used to make sure that two conditions are both true, that they are both meant by the program in order to print a message, were ordered to just simply take an action. But sometimes you just want one of the two conditions to be met and this will be sufficient for us to run the program. For example, if we have a university that tells us students that they could graduate, if they either complete a project or take a test. So either one of them can make them pass. To do this, we're going to use the board and it turns orange because it's built-in. So let's see how this works. Now, we're going to start with two variables. So test true. They will both hold Boolean values. Projects equals true and I set both of them to be equal to true at the beginning. Now here we're going to have to make a condition that the man's either the project or the test to be true in order to make the student be able to graduate. That's how project work tests. Well, wonderful. So python reads this as if project is true or test is true, then we can print well done. Else. So else means that if neither of them is true, so if they're both false, then we can move to the else statement to print. For example, please submit your. Now, let's set both of them to be true. I'm going to try all the combinations. So run, run module, okay? Now since both of them are true, then react well done because we have submitted at least one of the projects or the test. Let's set the test to be false. Run, run module. So this student decided to do the project, but not the test. The student did complete one assignment so he can graduate and well done. We can switch those two, true. It's student chose be tested over the project. But he still can graduate because he has completed the assignment. However, if we have a student that didn't complete either of them. So if he had the test equal to false and the project equal to false, meaning you didn't complete either assignment. It says please submit your work paintings that he did not graduate or he couldn't graduate until he does, either as a test for the project to until these turn true or until one of those turns true, then each congratulate. Now finally, I want you to know that n and four can be used with non Boolean values like numbers or strings. So let's have a quick, quick example. Let's have a equals to 50. Then is greater than 20. Hey, it's less than, let's say 75. Colon, cringe. Like tablets, some dots right there. Else. Print. Let's print some dashes. So if a was between 2075, we should get some dots. If it wasn't, we should get some dashes. Okay? Some dots because it is within the range. Let's change a to, for example, 500. Run, run module. Okay? You get some dashes. Now this is very symbolic just to show you the idea together, the cross. Once you understand it, you can use this in other useful situations. Now, as for strings, we can have a equals. Let's say yes. Then if a equals, equals yes. Okay. Else print. Sorry. Now again, this is just various involved. Just to show you the idea that we can use an if else statement with a string. So in case you didn't see that right there. We've got okay, because he is yes. Let's change that to know from your module. Okay. We get, sorry, I now finally, finally very important note is that here a was equal to yes. Just like that, we have a capital Y over here. Now this is different from the yes with a lowercase y. So these are considered two different strings. So it is going to execute the code under the else. Let's see that real quick. We get started again because it's not the same thing. 13. While loops: We usually use programming to perform tasks that are too repetitive, that take too much of our time and so it is very important to be able to execute a block of code repeatedly and easily. Here's where while loops come in, while loops work by going through a block of code repeatedly again and again until a condition that was initially set to be true becomes false. Very simple, very easy. Now let's go see that in practice. Now again, if you want to have a while loop, you must have a condition initially set to be true. And to do that, I'm going to have a variable called n That's going to be equal to 0. Wonderful, and that's going to have a while loop. The while loop is very simply a while. It turns orange because it's built-in and recognized by Python. Then we're gonna have something called the loop guard. It's basically the condition that was initially set to be true. So I'm going to have while n is less than or equal to ten, then a colon. now n is initially 0, so n is less than or equal to ten, so the condition is true. Now when you press Enter, you're gonna get an automatic indent. Now this is very important because whatever is beneath the while loop and indented is going to be repeated through again and again until this condition becomes false. So basically if the block of code that we keep repeating is anything indented beneath the wild loop. So the block of code I want to execute repeatedly is gonna be very simple. It's gonna be a code that will print numbers from 0 up to ten. And this is why we have the limits of 010 right over there. So to do that, I'm going to print n first of all. So this is going to initially print 0. Then I'm going to have a new value for n. I'm going to increase the value of n by one, so n equals n plus one. And there's a shorthand for this which is n plus equals one. So this means it's going to add one to the value of n so that this n is now equal to one. Okay? Now, let's see how this works. We have n initially set to be equal to 0, and then we're going to have while n is less than ten, which means as long as n is less than or equal to ten, we're going to execute this block of code. So we're going to print n, we're going to print 0, and then we're going to add one to the value of n. So we're going to increase the value of n by one. So the n has a new value which is now equal to one. So that one we're going to go to the top of the while loop and read it again. Is one is still less than or equal to ten. Yes, it is. So we're going to print one. Then, we're going to add one to one. So we get two, n is now equal to two. We go back to the top of the while loop and then we do is to still less than or equal to ten. It is. So we can print two, then we're going to add one to two, we get three, and so on and so forth. Until now eventually we're going to print all the numbers from 0 to ten. But here's what happens when we get to ten. Now, is ten less than or equal to ten? Yes, it is. It's equal to ten. So we're going to print ten and we're going to add one to ten. So n is now equal to 11. When we go back to the top of the while loop, we get is 11 less than or equal to ten, though it's not, the condition is no longer true. It is false. We don't execute this line of code. We go ahead and carry on with the normal code we have. So let's have a message that indicates that we're done with the while loop. So let's do print. and then Done. Let's see how this works. Let's run, run module. Okay. There we go. We have 012345678910. And then we're done because the while loop stops over here and we carry on with normal code over there. Well, let's see the application of a while loop. So basically we're going to have the user play a game. And then when they're done with the game, we're going to ask them if they want to play again. So first of all, we're going to ask them if they want to play game at all. So a equals input. Then do you want to play? Again? Question mark. We're going to guide them because I can either yes, we're now and now here we're going to have the while loop. And the loop guard or the condition will be whether a is equal to yes or not. So if a is equal to yes, we're gonna go ahead and continue with the wild. But it becomes no, then we're going to skip the whole thing and continue with our code. So let's write our condition is that a is equal to yes, remember it's a double equal time. Then a colon. Then here we can write the code for a game so that when the user types in, yes, they get to play a game. And let's have the game, the Mad Libs because you're already familiar with it. And I have them outlook already prepared. So I'm going to paste it over here. So variables equal to inputs and then we just print them until the sentences. It's very easy. You can have it rolled over here. And then we're going to ask the user if they want to play again. And their response will be the new value of a. So a equals b. But then, do you want to play again? Okay, let's have a yes-no guide them. So yes, no space. Wonderful. Now we're done with the code that is going to be executed as long as their answer is yes. But then when they type no, we're going to have to write something outside the while loop. For example, print, for example. Now here's how this works. We're going to have a equal to either yes or no based on what the user inputs. Now, if it is equal to yes, we're going to run the code for the game, so we're going to let them play this game. And then when they're done, we're going to ask them if they want to play again. If they do want to play again and they type in yes, Then a is still equal to yes. So we're going to run this code again. And then until the player decides that they don't want to play the game anymore when it snow. When it checks if a is equal to yes, it will be false because a is equal to know. So it's going to skip this while loop and go down there to print goodbye. Let's run this to see how it works. So do you want to play a game? Let's go with yes, Andrew, a car. Let's go with white. Plural noun. Let's go with celebrity, like the rock. So we've got roses or wipe out your blue while grew up. Do you want to play the game again? So I'm gonna go with yes, show you how we're going to get the exact same code repeated over and over again. And we can type in different colors. For example, we can go with green. Then for all now let's go with seats. Celebrity, for example, Taylor Swift. We got roses are green, seats are blue, and I'll Taylor Swift. You want to play a game again? Now let's see what happens if I type in notes. So no, goodbye. And as you can see, we're done with the code. 14. Functions: As programmers, it is always essential for us to be able to organize our code and to break it down into smaller, bite-sized pieces so that we can deal with and handle large quantities of code. This is exactly the purpose of a function. A function is very simply a collection of code that is used to perform a specific task. So if you have a bunch of lines of code that work together to do a specific task or an operation. Then you can just group them together and put them inside of a function. And now whenever you want to carry out this task or operation, you can just call that function. Writing functions is very easy. You first have to tell Python that you're about to write a function. To do this, we use the keyword def. When Python sees this, it knows that you're about to write a function. And then you're going to have the function name. And let's have ours called new_line. Now, when we name our function, we use the same rules when naming a variable. So basically we can't have spaces in their we have, an underscore. And second of all, we usually prefer this name is descriptive. So as a programmer, when I read new line, I have some sort of indication that we're about to insert a new line. We're about to write a code that is responsible for inserting a new line. Now it's not like this name over here has any effect on the code inside. You can have any name you want over here, and Python will be very fine with it. However, it is very useful for you as a programmer to have indicative names. Because when you have many functions, you're just gonna know which function you are referring to just by reading its thing. So then when you're done with naming, gets you add open and close brackets and then a colon. When you enter, you have an automatic indent. Now, anything indented beneath this function belongs inside the function. So any collection of code you write here is gonna be part of this function. And once you decided that you are done with writing the function, you can just go back to the main line. So let's start with writing the function. We're going to have a very simple collection of code. So first of all, remember indent and then print an empty space then the print, just like a line over here. Then finally print another empty space. so basically this is a function called new line. And the code inside it is going to print a space a line, then another space. Let's run this to see what happens. And as you can see, we don't get a result. And this is because if we want to execute a function, we have to call it first. To call a function, you just write its name. So new line, then open and close brackets. when I run this. I have my lines and spaces over here. Now let's see how we use this function. So for example, let's say I have a story. So print, oops, print. I love cherries. then Print. But I'm allergic to them. Print so I just ate just eigh. Okay, so this is a very short and meaningless story, but I'm using it to show you how we use our functions. So here the story is right there, but it's not very organized. Say I want to have it in some sort of paragraphs or something where each paragraph is separated by a space a line and another space so that it is more visually presentable. So what I can do is beneath each one of those, I can call the function. So new_line. And new_line. Now this is very useful because I did not have to rewrite this collection of code every time I wanted to insert a new line. And this is especially important when you're using very long functions and you don't want to keep writing again and again. So instead, you can just call the functions over here. Second of all, it helps us get a more organized program. 00:04:30.155 --> 00:04:32.975 So as you can see here, this is very short, very concise. It's easy to read as a programmer. But if you want to have all this clutter inside your code, it's gonna be much more difficult to navigate through. And this is much cleaner and much shorter and much easier to use. Now finally, let me show you how Python deals with this code. So it's going to start reading from here. It's going to print, I love cherries. And then it's going to find this function's name you like. So it's going to go up there and search for a function called new line right there. That's going to execute all the code inside this function. Then when it's done, it's going to go back to the original code and continue so print, but I'm allergic to them. It finds the name, prints this. Then it's going to print. So I just ate bananas, then it terminates the code. Let's run, run module. Okay, let'sSee this last time. We have this very nice piece of code. This is very simply how functions work in Python. 15. Class Project: I strongly believe that the best way to learn a skill is through practical work and project-based learning. And so I prepared a very quick lightweight project for you. And by completing get, you will have tested all of the key concepts in this class for this project, I want you to write a code for a program that offers 2 services. The first one is calculating the body mass index, or BMI, of the user. The second one will be a currency exchange program. You first want to welcome the user and introduce them to the two services you offer. Then we're going to ask them to choose one of them. And depending on what they choose, you're going to run certain lines of code to satisfy their request. Finally, you're going to ask them if they want to run the program. Again. If they do, you're going to have to run the program again. And if they don't, you can just print a goodbye message. And finally, remember to keep your code clean and visually organized. For more details, go ahead and check the projects and resources section down below, there you'll find the detailed task as well as a project guide and the sample solution attached. The project guide should give you hints along the way, and sample solution is my own attempted at completing the project. Now remember, your code can be very different from my code, from the code of all the students taking this class. This is what I love about Python. We can all be unique and creative while getting the task done. Once you're done, I encourage you to upload your project blow to get live feedback and to allow other students explore how you think and all the different possibilities of writing this code. I want you to upload a screenshot or screenshots of your program file, which is where you write your code, and the results that appear in the shell. So be sure to try your program out and then take a picture of it to show us how you did. Now should you need any assistance I'm always available to help. So be sure to leave your question in the discussion section down below. You got this. Good luck. 16. Recap: Conclusion : You've made it this far along this course. Congratulations. You've just moved from being an absolute beginner to someone who is very knowledgeable in Python, you can write very effective and useful lines of code. You have learned how to write to the world of simple and complex, comfortably houses built and effective, smart and interactive program room. And end up with a very thoroughly structured, well-organized program file was an immense pleasure to share my programming skills and experiences with you. And I hope you enjoyed learning Python just as much as I enjoy teaching. And now I encourage you to go ahead and attempt to completing your class project a down below to get live feedback, which will help you read out all the core concepts you learned throughout this class. And it will dominate these skills through project-based and practical learning. If you face any challenges anywhere along the course, feel free to drop your questions to the discussion section down below. You feel like you've walked away with something valuable from this class. How about you leave a good review so that other students can navigate through the same experience. One-off visit my profile and hit the Follow button while we're at it. Now because this class comes to an end, I would like to thank each and every one of you for your dedication. You got to do the work and unleash your creativity to the world of program. Remember, you're burning security.