Now let me explain two more primitive data types "Integers and Floats". Integers are used for presenting integers. Floats are used for representing rational numbers in maths. And also, in this video clip, I will explain variables and math operators. Variables I once mentioned in previous video clip, "x" was an example of variable. The name of variable, they are identifiers. So they must follow the rules of identifiers. What are the basic rules of identifier? The name of variable can be presented by characters and numbers. But numbers cannot come first. And also under bar or underscore, can be used for naming. And also, but, and also special characters cannot be used for naming variables or presenting identifiers. Variables are used for storing numbers, strings and Boolean values, or other non-primitive data types. And also, we are already study triple quotes, but for single-line comment, you can use hashtags here, hashtag. Sometimes is call pound sign, hash sign or pound sign. But in this MOOC course, I will use the term hash instead of pound. But definitely, you can use pound instead of a hash. Here's a cell adding two integers, "23 + 17". It means that Python can be used as a calculator, a simple calculator. So, What about simply "23 + 17"? Execute it. It returns "40". But what about you can use the print function. So "23 + 17" that formula is inserted within print function. The same value is returned. It means that instead of text information, a formula can be inserted in print function. That formula is excuted and outcome is printed. As I did before, what if I add a hash sign? Then print command line becomes dormant, not working. And the outcome of "23 + 17" is printed. But you may say that why when the print function is active, only one outcome is printed? Because that's the rule of this Jupyter Notebook. When multiple outcomes should be printed, only the last line is printed. Two integers, are divided "2/3". Then, what happens? A rational number, a rational number is returned "2/3". It means that when two integers when two integers are used for division, the data type returned is float, not integer. Obviously, a rational number is represented by division. So, a float is use for representing a rational number. Another case, "x" variable has 23 and "y" variable has 17. It is assigning a way of assigning values to variables. This is a way of assigning values to variables, "x" and "y" variables, and 23 and 17 are assigned to each variable. "print(x+y)" and "print(x+y, x-y, x * y, x/y)". So, four arithmetic operations contained in the print function. If we execute it what happens? Addition, subtraction, multiplication, and division are done. And if you write multiple print functions, all outcomes for each print function is printed. Another way of assigning values to variables is this one. For example, make this one dormant by adding hash and another hash. Then right now, four is assigned to "x", and five is assigned to "y". And then execute. So based on new values assigned to "x" and "y", four arithmetic operations are done, and they are printed. So which one is better? Ah, this is it's more efficient coding. So, what about if you want to add another variable and assign a value? You can simply add "z" and 7 comma, comma-separated. In that case, four is assigned to "x", five is assigned to "y" and seven is assigned to "z". This is a simple way of assigning values to multiple variables. Now, here's another way of presenting outcomes. In this case, basically, the same as you studied above, but print function contains text information, comma-separated, and formula. So, the print function can take string information and formula information. Then outcome of calculation, addition operation is printed with the text information. So here's a case of subtraction, multiplication, and division. This is the exponent you are squaring "y" value, and two asterisk are used for exponent, making exponent. How can you make a square root? In that case, this exponent simply becomes one of two. And two more new concept is introduced here, double division. This is the floor division, not double division. But two double division sign is use. So that is floor division. Floor division returns the highest integer, which is not greater than the result. For example, if the result is "1.5", "1" is returned, the integer part is returned. Then how can you get remainder? The remainder is percent sign. "z % y" means that here "z % y". It is if the value is division value is "1.5", then only "0.5" is returned. The remainder is returned. And data type, let's check data type of "y" and "z". In this case "y" is an integer, "z" is float, right? So, let's execute this cell. Then obviously, addition is "12.5", subtraction is "2.5", multiplication is "37.5", division outcome is "1.5" and "y" squared is "25", floor division is "1.0" and remaining, remaining is "2.5" "z % y", "z" divide by "5", then the remainder is "2.5". And integer data type and float data. That's what I already explained before closing this video clip here's again, a review question. True or False, true or false: the data type of "4/2" is integer. Is this true? Is this sentence True. Two integers are divided by an integer four divided by two. Then there's no remainder in this case. Is it float or integer? The answer is float. So, the answer is False, not an integer. So, if you try whether it is really an integer or a float, four divided by two, the result is 2.0, so it is float.
