Hi. Now let me introduce another two type of functions. The first one that I want to introduce to you is a function with default parameter values. Now, let me give you an example. A function with default parameter values. This function is already def is announced then the name of function rectangle is announced read in parenthesis. At this time two variable, width is equal to three, height is equal to five. It means that width variables default value is three, height variables default value is five, and docstring said calculating the area of a rectangle. Actually, this tool is calculating area of rectangle, after taking two values it returns one output, which is area of a rectangle. It returns width multiplied by height, which is the formula of calculating the area of rectangle. Let me create that object dysfunction, so rectangle object is created. Now, let me implement three rectangle area calculations. At this time here, print function had three object. Rectangle, no information is provided simply because we already set default values for the two variables. If no input values are provided, then default input values will be used for calculation and default area information will be returned. That's the benefit of using default parameter values in defining a parameter. Sometimes, by mistake, maybe someone does not provide any information, then if default values are not set, then error message it comes up. But at this time no error message, default area value will be returned. In this case, only one value is provided, five, then which value will take that value? If there's only one, for us to variable, it means that five will be assigned to width local variable. Then the third one takes two input values for N5. At this time, it calculates the area information of rectangle using this formula. Though provided value so let me execute, then 15 because that is the area based on default values. Twenty-five, five is assigned to width, so 5 times 5 is 25. For N5, two values are provided. Four is used for width, five is used for height, so 4 times 5, which is 20. The other case here, at this time, height is announced as four. It means that if you provide just one value, it means that they'll be used for width not height. In order to avoid that confusion, you specify number four is assigned to height, then what area information will be provided, 3 times 4, 12 will be returned. Look at this one. Height is six, width is seven. In this case, variable name is switched, but as long as you announced what is height, which one is height, which one is width, no problem at all. But what about you do not give height or width variable name? Then six will be used for width, seven will be used for height. Surely at this time, the area information does not change, but what about your care creating different formula? In that case, depending on which value is used for which variable, the outcome could be different. But at this time, luckily there's no change, but anyway, what I want to tell you here is that, by venue specified local variable name, the order does not matter, so tribe 42 is printed. Now let me introduce another type of function. This function takes an arbitrary number of arguments. It means that you cannot predetermine how many values will be typed in for calculation. In that case, you may use this function taking arbitrary number of arguments so I create my average here. It takes multiple values and calculates returns average value. In that case, you need to simply add asterisk and any variable number, nums, at this time, but you can use x, or y, or z, any variable name. Then doctrine comes calculating average value with multiple numbers. This is what this function does and returns, I'm using built-in functions. One is some built-in function adding the numbers provided and this count, count number provided, so length function character count the number of numbers provided. Let's create this my average function, and then I'm providing, for example, five numbers here, then 69.6, that is the average value. If you are schoolteacher, there are like 20 students in your class, you want to calculate average score or grade on an exam, in that case you can use this function. But what about there are so many numbers? In that case, the number can be taken as a list concept that I already explained. There are 10 numbers from 1-10, so you take this grade information from Excel sheet, but you assign and that multiple, many numbers to graze list object, then you simply, in order to use my average function, you put asterisk here, and then the name of list containing multiple grades, then it calculates average value of 5.5. If you add number 1-10, the sum is 55, how many numbers are added? Ten numbers added. 55 divided by 10, which is 5.5, that is the answer. I introduced two special functions, true or false? A function with default values can be called without providing argument values, true or false? What is your answer again? Your answer will be true. A function with default values. Sometimes you don't have to provide argument values because already default value is assigned pre-specified in the function.
