Reference no: EM13168104

We can combine assignment statements, for-loops, and if statements to perform a wide range of tasks with lists. Suppose we have a bookstore with each book defined as follows:Book = namedtuple('Book', 'author title genre year price instock'), where "genre" is the category of book (e.g., cookbook or mystery or sports), "year" is the year of publication, and "instock" is the number of copies of that book we have available to sell. Make up a half-dozen Book structures and combine them into a list called BSI (for "book store inventory").

(e.1) Write a sequence of statements that prints the title of each book in BSI, one per line.

(e.2) Write a sequence of statements that prints the title of each book in BSI, one per line, in alphabetical order; do this without changing the original order of BSI.

(e.3) Write a sequence of statements that raises the price of each book in BSI by 10%; this does change the value of BSI.

(e.4) Write a sequence of statements that prints the title of each book in BSI whose genre is Technology.

(e.5) If we ask how many books there are in our list BSI, there are two possible answers: One is just the number of items in the list, each representing a different author/title combination (book publishers call this the number of "titles"); the other is the number of individual, physical books in the store's inventory (i.e., the sum of all the instock figures of all the "titles" in the list).

Write a sequence of statements that creates a new list containing the Books ("titles") in BSI that were published before 2000 and a second new list of Books published in 2000 or later. Then write a sequence of statements that prints one of these phrases: More titles before 2000 or More titles 2000 or later. Finally, add to whichever message you print the number of titles in each category, in a form like this: More titles 2000 or later (345 vs. 189). [Hint: To create a new list in this way, start with an empty list. Then, each time you find a new Book that belongs on the list, add that Book to the list. When you've gone through the original list, your new list will have the Books you want. Second hint: There's a simple predefined function that will tell you the number of Books on a (newly created) list.]

(e.6) The value of the inventory of a particular book is the price of that book times the number of copies we have in stock. Write a function called inventory_value that takes a Book as its argument and returns the value of our inventory of that book. Then write a function called top_value that takes a list of Books as its argument and returns the Book object (from the list) that has the highest-vaue inventory. Finally, write a sequence of statements that prints a line in this form: The highest-value book is War and Peace by Tolstoy, Leo at a value of $ 595.00.

(f) Write a series of tkinter statements to draw a face, with a mouth, a nose, and two eyes. Use your eye-drawing code from last week's lab. But don't just copy those lines twice! Even if you use copy and paste to avoid tedious retyping, duplicate code is always a problem: It makes the program longer, and if you have to change it, you have to change every copy. If you skip changing one copy of the duplicate code, your program becomes an inconsistent mess. Happily, we've learned how to avoid writing duplicate code in this situation: We design a function called draw_eye to contain our eye-drawing code; then we call that function twice, once for each eye. But there's one more step, because we don't want to draw both eyes in the same place. Our draw_eye function needs parameters that specifies the starting point for the drawing; then we can call it twice, one with a starting point that's offset from the other.

Write a function called draw_face that calls functions (that you also write) called draw_eye, draw_nose, and draw_mouth. Your nose and mouth don't have to be as fancy as your eyes; in fact, make them as crude and simple as you can to start with, and only refine them if you have time. Include at least two calls to draw_face in your lab3.py file.

(If you're feeling ambitious and have the time, parameterize other aspects of your feature-drawing functions so you can easily draw faces with different-color eyes, different-sized noses, and so on.)