Week 4 - Quiz (Programming, Datastructures and Algorithms using Python) (NPTEL 2022 - CS26)

 All questions carry equal weightage. All Python code is assumed to be executed using Python3. You may submit as many times as you like within the deadline. Your final submission will be graded.

Note:

• If the question asks about a value of type string, remember to enclose your answer in single or double quotes.
• If the question asks about a value of type list, remember to enclose your answer in square brackets and use commas to separate list items.

Consider the following Python function.

def mystery(l,v):
  if len(l) == 0:
    return (v)
  else:
    return (mystery(l[:-1],l[-1]+v))

What does mystery([22,14,19,65,82,55],1) return?

Accepted Answers:

(Type: Numeric) 258

2.5 points

What is the value of triples after the following assignment?

triples = [ (x,y,z) for x in range(2,4) for y in range(2,5) for z in range(5,7) if 2*x*y > 3*z ]

Feedback:

triples = []
for x in range(2,4):      # x = 2,3
  for y in range(2,5):    # y = 2,3,4
    for z in range(5,7):  # z = 5,6
      if 2*x*y > 3*z:
         triples.append((x,y,z))
         
Output: [(2, 4, 5), (3, 3, 5), (3, 4, 5), (3, 4, 6)]

Accepted Answers:

[(2, 4, 5), (3, 3, 5), (3, 4, 5), (3, 4, 6)]

2.5 points

2.5 points

Consider the following dictionary.

runs = {"Test":{"Rahul":[90,14,35],"Kohli":[3,103,73,42],"Pujara":[53,15,133,8]},"ODI":{"Sharma":[37,99],"Kohli":[63,47]}}

Which of the following statements does not generate an error?

 runs["ODI"]["Rahul"].append([74])

 runs["ODI"]["Rahul"].extend([74])

 runs["ODI"]["Rahul"][0]=74

 runs["ODI"]["Rahul"]=[74]

Feedback:

runs["ODI"]["Rahul"] creates a new key, so one can only assign it a fresh value, not access parts of the value or append to or extend the value.

Accepted Answers: D

runs["ODI"]["Rahul"]=[74]

2.5 points

Assume that actor has been initialized as an empty dictionary:

actor = {}

Which of the following generates an error?

 actor["Star Wars"] = ["Rey","Ridley"]

 actor["Star Wars, Rey"] = "Ridley"

 actor[["Star Wars", "Rey"]] = "Ridley"

 actor[("Star Wars", "Rey")] = "Ridley"

Feedback:

Dictionary keys mus be immutable values.

Accepted Answers: C

actor[["Star Wars", "Rey"]] = "Ridley"