[Python OOP] Inheritance, special function

Look at the code snippet in the screenshot. If you run the screenshot, what will happen?

• It will raise an error: Rectangle class does not have method "printMe" defined.

• It will raise an error: Rectangle class is empty. Python does not allow that.

• It will run, and print "Shape: generic shape" on screen.

• It will run, but nothing will be printed on screen.

Look at this code snippet (screenshot). What will happen if you run it?

• An error will occur: Rectangle class has two "printMe" methods. Cannot resolve which method to use.

• It will print "Shape: generic shape" on screen

• It will print "Shape: Rectangle" on screen

• It will print two lines:
  Shape: generic shape

  Shape: Rectangle

Look at the code snippet (screenshot). What happens if you run it?

• An error will occur.

• It will print "Shape Rectangle"

• It will print:
  Shape: Rectangle

  shape: generic shape

• It will print:

  Shape: generic shape

  Shape: rectangle

Look at the code snippet. Note there's a blank "______" in the snippet. Suppose we would like to make "Shape" an abstract class, by keeping "printMe" method not implemented. Which option is correct to fill in the blank?

• return NotImplemented

• raise NotImplementError("printMe method not implemnted!")

• return NotImplementedError("printMe method not implemnted!")

• return None

Recall that Python str class support "+" operation: "abc" + "ef" => "abcef". Which special method must the str class have implemented?

• def __str_ _

• def str

• def __add_ _

• def __eq_ _

This code snippet shows the definition of "Stack" class. Which option(s) of the following is correct to get the size of the stack object s (assign to variable n)?

• n = s.size()

• n = s.len()

• n = len(s)

• n = len(s.__list)

Look at the snippet for Stack class. What's the time complexity of "push", "pop" and "get" methods? (N: size of stack)

• push: O(1)

  pop: O(1)

  get: O(1)

• push: O(N)

  pop: O(N)

  get: O(1)

• push: O(1)

  pop: O(1)

  get: O(N)

• push: O(N)

  pop: O(N)

  get: O(N)