In-Class Questions and Video Solutions

Lecture 8

  1. Class Definition

    Which of the following is a good and valid definition for a class representing a car?

    def class Car(object): close
    class Car(object): check
    def Car(object): close
    class A(object) close
    Check Show Solution

  2. Class Instance

    Using the class definition below, which line creates a new Car object with 4 wheels and 2 doors?

    class Car(object):
     def __init__(self, w, d):
      self.wheels = w
      self.doors = d
      self.color = ""
    

    Car(mycar, 4, 2) close
    mycar = Car(4, 2, "white") close
    mycar = Car(4, 2) check
    mycar = Car(2, 4) close
    Check Show Solution

  3. Methods

    Which of the following methods changes the color of the car, based on the definition below?

    class Car(object):
     def __init__(self, w, d):
      self.wheels = w
      self.doors = d
      self.color = ""
    

    def paint(c): color = c close
    def paint(self, c): color = c close
    def paint(c): self.c = c close
    def paint(self, c): self.color = c check
    Check Show Solution

  4. Method Call

    You create a car with mycar = Car(4, 2). Which is a line of code to change the color of mycar to “red”?

    class Car(object):
     def __init__(self, w, d):
      self.wheels = w
      self.doors = d
      self.color = ""
      def paint(self, c):
       self.color = c
    

     Car.paint("red")  close
     mycar.paint(red)  close
     mycar.paint("red")  check
     mycar.paint(Car, "red")  close
    Check Show Solution

  5. Special Methods

    With the code below, what does the line print(mycar == yourcar) print?

    class Car(object):
     def __init__(self, w, d):
      self.wheels = w
      self.doors = d
      self.color = ""
     def paint(self, c):
      self.color = c
     def __eq__(self, other):
      if self.wheels == other.wheels and \
      self.color == other.color and \
      self.doors == other.doors:
       return True
      else:
       return False
    
    mycar = Car(4, 2)
    mycar.paint("red")
    yourcar = Car(4,2)
    print(mycar == yourcar)
    

     True  close
     False  check
     An error  close
    Check Show Solution

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