There was a mistake in entering grades on Canvas. We need your help writing a Python script that can help us maintain the class roster. The functionalities you need to implement are explained below. For each of the functionalities, you may want to implement a separate function.

Adding a student to the roster:
When you receive the "add NAME GRADE" command, you need to add one student with the name "NAME" and the grade "GRADE" to the roster. For example, "add Simon 20" will add Simon to the roster and his grade will be 20. If the entered grade was greater than 100, or if the student’s name is already on the roster, then don’t add the student to the roster and instead print "Failed to add NAME", with NAME being the name of the student you were asked to add to the roster. If adding the student was successful, you will print "Added NAME", with NAME being the name of the student you just added.
Updating the grade of an existing student:
When you receive the "update NAME GRADE" command, you will have to check if the student with the name "NAME" exists in the roster. If so, update their grade to "GRADE" and print "Updated NAME’s grade" with NAME being the name of the student. Otherwise, print "NAME does not exist in the roster".

Printing the roster:
When you receive the "print" command, you need to print the entire roster in the output in the same order that you added students to the roster. For example, if we have {‘Narges’: 0, ‘Benedict’: 1} on our roster, it will print:
Narges: 0
Benedict: 1

Exiting the program:
When you receive the "exit" command, you will terminate the program and stop receiving inputs from the user.
Sample Input 1:

add narges 0
print
exit
Sample Output 1:

Added narges
narges: 0
Sample Input 2:

add Benedict 1
add Rafael 11
add michael 111
exit
Sample Output 2:

Added Benedict
Added Rafael
Failed to add michael
Sample Input 3:

add Katelyn 99
print
update Katelyn 100
print
update Rafael 98
exit
Sample Output 3:

Added Katelyn
Katelyn: 99
Updated Katelyn's grade
Katelyn: 100
Rafael does not exist in the roster
Sample Input 4:

add Ben 10
add Bao 11
update bao 12
print
update Bao 12
print
exit
Sample Output 4:

Added Ben
Added Bao
bao does not exist in the roster
Ben: 10
Bao: 11
Updated Bao's grade
Ben: 10
Bao: 12
Sample Input 5:

update Yama 80
add Yama 80
add Yama 90
update Yama 100
print
exit
Sample Output 5:

Yama does not exist in the roster
Added Yama
Failed to add Yama
Updated Yama's grade
Yama: 100

Calculating the "total price" of an item is tedious, so implement a get_item_cost method that just returns the quantity times the price for an item. by the way, the technical term for this kind of instance method is an accessor method, but you'll hear developers calling them getters because they always start with "get" and they get some value from instance attributes. in order to make the items sortable by their total total price, we need to customize our class. search the lectures slides for "magic" to see how to do this. see section 9.8 for an additional reference. the receipt class: this will be the class that defines our receipt type. obviously, a receipt will consist of the items on the receipt. this is called the composition design pattern. and it is very powerful. instance attributes: customer_name : it is very important to always know everything you can about your customers for "analytics", so you will keep track of a string customer name in objects of type receipt. date : the legal team has required that you keep track of the dates that purchases happen for "legal reasons", so you will also keep track of the string date in objects of type receipt. cart_items : this will be a list of the items in the cart and hence end up on the receipt. methods: 1. create a default constructor that can take a customer name as an argument, but if it gets no customer name, it will just put "real human" for the customer_name attribute. it should also accept a date argument, but will just use the value "today" for the date instance attribute if no date is given. the parameters should be named the same as the instance attributes to keep things simple. 2. add_item : self-descriptive. takes a parameter which we hope beyond hope is of type itemtopurchase and adds it to the cart_items. returns none. 3. print_receipt : takes a single parameter isevil, with default value true. returns a total cost of all the items on the receipt (remember to factor in the quantity). prints the receipt based on the following specification: for example, if isevil is true, and customer_name and date are the default values: welcome to evilmart, real human today have an evil day! otherwise, it should print: welcome to goodgo, real human today have an good day! then the receipt should be printed in sorted order like we discussed earlier, but whether or not it starts with the highest cost (think reverse), depends on the value of isevil. if it is evil, then the lowest cost items should print first, but if it is good, then it will print the highest cost items first. (cost meaning price*quantity). remember to return the total cost regardless! your main() function: the main flow of control of your program should go in a main() function or the program will fail all the unit tests. get the name of the customer with the prompt: enter customer name: get the date with the prompt: enter today's date then, ask the question: are you evil? your program should consider the following as true: yeah yup let's face it: yes hint: what do these strings all have in common? your program should consider all the following as false: no nah perhaps but i'm leaning no (just be glad you don't have to handle "yeah no.") okay enough horsing around. (get it? aggies? ! horsing! ) next, in the main() function, you will have to create a receipt object and start adding things into it using an input-while loop. the loop will prompt the user for the item name exactly as in the previous zylab (9.11). but unlike the previous zylab, the loop will terminate only if an empty string is entered for the item name. then, the price and the quantity will be prompted for exactly as in the previous zylab. create the itemtopurchase objects in the same manner as the previous zylab, but don't forget to add them to the receipt using your add_item instance method. then, the items on the receipt should be printed with the same formatting as in the previous zylab, of course with either "good" or "evil" ordering. however, on the last line, the total should be printed as follows: where 10 is replaced by the actual total. sample run here is what a sample run of the final program should look like: enter customer name: nate enter today's date: 12/20/2019 are you evil? bwahahahaha yes enter the item name: bottled student tears enter the item price: 2 enter the item quantity: 299 enter the item name: salt enter the item price: 2 enter the item quantity: 1 enter the item name: welcome to evilmart, nate 12/20/2019 have an evil day! salt 1 @ $2 = $2 bottled student tears 299 @ $2 = $598 total: $600

What is an rss reader used for? for creating a user account on a social new site

Which one of the following functions is not available on the autosum tool? sum average if max