15-112 OOP Practice

  1. Gate class and Subclasses: OOP Practice
    A logic gate is a physical device that creates the functional equivalent of a logic operation in code [and, or, not]. It takes some number of input values, such as two values for and (input1 and input2), and produces a single output value. Write the Gate classes required to make the following test function work properly.

    def getLocalMethods(clss): import types # This is a helper function for the test function below. # It returns a sorted list of the names of the methods # defined in a class. result = [ ] for var in clss.__dict__: val = clss.__dict__[var] if (isinstance(val, types.FunctionType)): result.append(var) return sorted(result) def testGateClasses(): print("Testing Gate Classes... ", end="") # require methods be written in appropriate classes assert(getLocalMethods(Gate) == ['__init__', '__str__', 'numberOfInputs', 'setInput']) assert(getLocalMethods(AndGate) == ['getOutput']) assert(getLocalMethods(OrGate) == ['getOutput']) assert(getLocalMethods(NotGate) == ['getOutput', 'numberOfInputs']) # make a simple And gate and1 = AndGate() assert(type(and1) == AndGate) assert(isinstance(and1, Gate) == True) assert(and1.numberOfInputs() == 2) and1.setInput(0, True) and1.setInput(1, False) # Hint: to get the name of the class given an object obj, # you can do this: type(obj).__name__ # You might do this in the Gate.__str__ method... assert(str(and1) == "And(True,False)") assert(and1.getOutput() == False) and1.setInput(1, True) # now both inputs are True assert(and1.getOutput() == True) assert(str(and1) == "And(True,True)") # make a simple Or gate or1 = OrGate() assert(type(or1) == OrGate) assert(isinstance(or1, Gate) == True) assert(or1.numberOfInputs() == 2) or1.setInput(0, False) or1.setInput(1, False) assert(or1.getOutput() == False) assert(str(or1) == "Or(False,False)") or1.setInput(1, True) assert(or1.getOutput() == True) assert(str(or1) == "Or(False,True)") # make a simple Not gate not1 = NotGate() assert(type(not1) == NotGate) assert(isinstance(not1, Gate) == True) assert(not1.numberOfInputs() == 1) not1.setInput(0, False) assert(not1.getOutput() == True) assert(str(not1) == "Not(False)") not1.setInput(0, True) assert(not1.getOutput() == False) assert(str(not1) == "Not(True)") print("Passed!") testGateClasses()

  2. Book class: OOP Practice
    Write the Book class so that it passes testBookClass, and uses the OOP constructs we learned this week as appropriate.
    def testBookClass(): print("Testing Book class...", end="") # A Book has a title, and author, and a number of pages. # It also has a current page, which always starts at 1. There is no page 0! book1 = Book("Harry Potter and the Sorcerer's Stone", "J. K. Rowling", 309) assert(str(book1) == "Book<Harry Potter and the Sorcerer's Stone by " + "J. K. Rowling: 309 pages, currently on page 1>") book2 = Book("Carnegie Mellon Motto", "Andrew Carnegie", 1) assert(str(book2) == "Book<Carnegie Mellon Motto by Andrew Carnegie: " + "1 page, currently on page 1>") # You can turn pages in a book. Turning a positive number of pages moves # forward; turning a negative number moves backwards. You can't move past # the first page going backwards or the last page going forwards book1.turnPage(4) # turning pages does not return assert(book1.getCurrentPage() == 5) book1.turnPage(-1) assert(book1.getCurrentPage() == 4) book1.turnPage(400) assert(book1.getCurrentPage() == 309) assert(str(book1) == "Book<Harry Potter and the Sorcerer's Stone by " + "J. K. Rowling: 309 pages, currently on page 309>") book2.turnPage(-1) assert(book2.getCurrentPage() == 1) book2.turnPage(1) assert(book2.getCurrentPage() == 1) # You can also put a bookmark on the current page. This lets you turn # back to it easily. The book starts out without a bookmark. book3 = Book("The Name of the Wind", "Patrick Rothfuss", 662) assert(str(book3) == "Book<The Name of the Wind by Patrick Rothfuss: " + \ "662 pages, currently on page 1>") assert(book3.getBookmarkedPage() == None) book3.turnPage(9) book3.placeBookmark() # does not return assert(book3.getBookmarkedPage() == 10) book3.turnPage(7) assert(book3.getBookmarkedPage() == 10) assert(book3.getCurrentPage() == 17) assert(str(book3) == "Book<The Name of the Wind by Patrick Rothfuss: " + \ "662 pages, currently on page 17, page 10 bookmarked>") book3.turnToBookmark() assert(book3.getCurrentPage() == 10) book3.removeBookmark() assert(book3.getBookmarkedPage() == None) book3.turnPage(25) assert(book3.getCurrentPage() == 35) book3.turnToBookmark() # if there's no bookmark, don't turn to a page assert(book3.getCurrentPage() == 35) assert(str(book3) == "Book<The Name of the Wind by Patrick Rothfuss: " + \ "662 pages, currently on page 35>") # Finally, you should be able to compare two books directly book5 = Book("A Game of Thrones", "George R.R. Martin", 807) book6 = Book("A Game of Thrones", "George R.R. Martin", 807) book7 = Book("A Natural History of Dragons", "Marie Brennan", 334) book8 = Book("A Game of Spoofs", "George R.R. Martin", 807) assert(book5 == book6) assert(book5 != book7) assert(book5 != book8) book5.turnPage(1) assert(book5 != book6) book5.turnPage(-1) assert(book5 == book6) book6.placeBookmark() assert(book5 != book6) print("Done!")