Which of the following expressions mutate, i.e., change, list my_list?
Answer
my_list.reverse()
my_list.extend([10, 20])
my_list + [10, 20]
my_list.append(10)
another_list.extend(my_list)
Question 3
Question
Every class definition should include an initializer method. Is _init_ that method?
Answer
True
False
Question 4
Question
We can loop over strings, too!
The following incomplete function is a simple, but inefficient, way to reverse a string. What line of code needs to replace the questions marks for the code to work correctly?
def reverse_string(s):
"""Returns the reversal of the given string."""
[blank_start]result[blank_end] = ""
for char in s:
result = char + result
return result
print reverse_string("hello")
Imagine a game on a map. At the beginning, we might want to randomly assign each player a starting point. Which of the following expressions may we use in place of the question marks to correctly implement this functionality?
import random
def random_point():
"""Returns a random point on a 100x100 grid."""
return (random.randrange(100), random.randrange(100))
def starting_points(players):
"""Returns a list of random points, one for each player."""
points = []
for player in players:
point = random_point()
[blank_start]points.append(point)[blank_end]
return points
Answer
points + point
points.extend(point)
point.append(points)
points.append(point)
points += point
Question 6
Question
The following function is supposed to check whether the given list of numbers is in ascending order. For example, we want is_ascending([2, 6, 9, 12, 400]) to return True, while is_ascending([4, 8, 2, 13]) should return False.
def is_ascending(numbers):
"""Returns whether the given list of numbers is in ascending order."""
for i in [blank_start]range(len(numbers)[blank_end]):
if numbers[i+1] < numbers[i]:
[blank_start]return False[blank_end]
return True
However, the function doesn't quite work. Try it on the suggested tests to verify this for yourself. The easiest fix is to make a small change to the highlighted code. What should it be replaced with?