Question 1

Question 1Assertion (A): List in Python is a collection of values of any type.Reasoning (R): In lists, you can change the elements of a list in place.Both A and R are true and R is the correct explanation of A.Both A and R are true but R is not the correct explanation of A.A is true but R is false.A is false but R is true.

Accepted Answer

Both A and R are true but R is not the correct explanation of A.ExplanationList in Python is a collection of values of any type such as strings, integers, floats, objects or even a list. Lists in Python are mutable, meaning we can change the elements of a list in place.

Question 2

Question 3Which of the following statements is correct about list?List can contain values of mixed data types.List can contain duplicate values.A list with no elements is called an empty list.All of these

Accepted Answer

All of theseReason — Lists in Python can contain values of mixed data types, such as integers, strings, and floats. They can also contain duplicate values, meaning the same value can appear more than once in the list. Additionally, a list with no elements is called an empty list, represented as [].

Question 3

Question 8The sequential accessing of each of the elements in a list is called:List IndexingList TraversalList SlicingList Accessing

Accepted Answer

List TraversalReason — The sequential accessing of each of the elements in a list is called list traversal.

Source: This question is from Lists in Python, Computer Science &mdash; Class 11, CBSE Board.
Key Concepts CoveredThis question tests your understanding of the following concepts from the chapter Lists in Python: Question, Sequential, Accessing, Elements, Indexing, Traversal. These are fundamental topics in Computer Science that students are expected to master as part of the CBSE Class 11 curriculum.A thorough understanding of these concepts will help you answer similar questions confidently in your CBSE examinations. These topics are frequently tested in both objective and subjective sections of Computer Science papers. We recommend revising the relevant section of your textbook alongside practising these solved examples to build a strong foundation.
How to Approach MCQsMultiple choice questions test your ability to quickly recall facts and apply concepts. Read all options carefully before selecting your answer. Use the process of elimination to rule out clearly incorrect options first. If two options seem similar, look for the subtle difference that makes one more accurate. For numerical MCQs, verify your answer by substituting it back into the problem.
Key Points to RememberWrite programs with proper indentation and comments.
Trace through your code with sample inputs to verify correctness.
Explain the logic behind each step of your solution.
Familiarise yourself with common library functions and methods.
Related Questions from Lists in PythonQ1: Question 1 Assertion (A): List in Python is a collection of values of any type. Reasoning (R): In...
Q10: Question 8(c) What will be the output of the following statement? list1 = [ 1 , 2 , 3 , 4 , 5 , 6 ,...
Q11: Question 8(d) What will be the output of the following statement? list1 = [ 1 , 2 , 3 , 4 , 5 ]...
Q12: Question 9 What will be the output of the following code segment? myList = [ 1 , 2 , 3 , 4 , 5 , 6...
Q13: Question 10(a) What will be the output of the following code segment? myList = [ 1 , 2 , 3 , 4 , 5...
Practice more questions from Lists in Python &mdash; Computer Science, Class 11 CBSE

Question 4

Question 2What are the similarities between strings and lists?

Accepted Answer

Both strings and lists are sequential data types, meaning they store elements in a specific order. They support indexing, allowing access to individual elements using square brackets notation '[]'. Additionally, both strings and lists support slicing, enabling us to extract portions of the sequence using the colon (:) operator. They can also be iterated over using loops such as for loops, facilitating access to each element one by one in the sequence. Furthermore, both strings and lists support the in and not in operators, which check for the presence or absence of a particular element in the sequence.

Question 5

Question 4Define the following functions:(a) len()(b) append()(c) extend()(d) pop()(e) remove()(f) del(g) sort()(h) sorted()(i) copy()(j) count()(k) max()(I) min()(m) sum()

Accepted Answer

(a) len() — The len() function returns the length of the list, i.e., the number of elements in a list.(b) append() — The append() method adds a single item to the end of the list. It does not create a new list, rather it modifies the original list.(c) extend() — The extend() method adds one list at the end of another list. In other words, all the items of a list are added at the end of an already created list.(d) pop() — The pop() method removes the element from the specified index and also returns the element which was removed.(e) remove() — The remove() function removes the first occurrence of the item from the list. It is useful when we know the element to be deleted but not the index of the element.(f) del — The del statement removes the specified element from the list but does not return the deleted value.(g) sort() — The sort() function sorts the items of the list, by default in ascending/increasing order. To sort the list in descending order we use reverse = True parameter. Sorting is done 'in place', i.e., it does not create a new list.(h) sorted() — The sorted() method takes a list as a parameter and creates a new list consisting of the same elements but arranged in ascending order and returns it as a list. To sort the list in descending order we use reverse = True parameter.(i) copy() — The copy() function returns a new list stored in a different memory location.(j) count() — The count() method counts how many times an element has occurred in a list and returns it.(k) max() — The max() method returns the element with the maximum value from the list.(I) min() — The min() method returns the element with the minimum value from the list.(m) sum() — The sum() function in Python is used to calculate the sum of all the elements in list.

Question 6

Question 5What is the difference between insert() and append() methods of a list?

Accepted Answer

Insert MethodAppend MethodThe insert() method is used to add an element at a specific index in the list.The append() method is used to add an element at the end of the list.The syntax is: list.insert(index, element).The Syntax is: list.append(element).Example: my_list.insert(2, 'hello') will insert the string 'hello' at index 2 in the list my_list.Example: my_list.append('world') will add the string 'world' at the end of the list my_list.

Question 7

Question 6Suppose L = [10, ["few", "facts", "fun"], 3, 'Good']Consider the above list and answer the following:(a) L[3:](b) L[::2](c) L[1:2](d) L[1] [1]

Accepted Answer

(a) L[3:] — ['Good']ExplanationThe slice L[3:] will include the element at index 3 and any elements that follow it. Since index 3 is the last element, L[3:] will include only ['Good'].(b) L[::2] — [10, 3]ExplanationThe slice L[::2] means to include every second element from the list, starting from the beginning. This results in selecting the elements at indices 0 and 2, which are 10 and 3.(c) L[1:2] — [['few', 'facts', 'fun']]ExplanationThe slice L[1:2] selects elements from index 1 up to, but not including, index 2. This means it includes only the element at index 1, which is ["few", "facts", "fun"].(d) L[1] [1] — factsExplanationThe expression L[1][1] first accesses the sub-list at index 1, which is ["few", "facts", "fun"], and then accesses the element at index 1 of that sub-list, which is "facts". Therefore, L[1][1] evaluates to "facts".

Question 8

Question 7Find the output of the following:L1=[1, 2, 3]
L2=[4, 5, 6]
print(L1+list ("45") )
print(L1.pop())
L1.remove (2)
print(L1)
L1.extend (L2)
print(L2)

Accepted Answer

Output[1, 2, 3, '4', '5']
3
[1]
[4, 5, 6]
ExplanationIn the above code, L1 is defined as [1, 2, 3] and L2 as [4, 5, 6]. The first print(L1 + list("45")) concatenates L1 with the list representation of the string "45", resulting in [1, 2, 3, '4', '5']. The next operation print(L1.pop()) removes and returns the last element of L1, which is 3, printing it. Then, L1.remove(2) removes the element 2 from L1, leaving [1]. Subsequently, L1.extend(L2) appends elements from L2 to L1, modifying it to [1, 4, 5, 6]. Lastly, print(L2) outputs [4, 5, 6], showing that L2 remains unchanged despite being extended into L1.

Question 9

Question 8(b)What will be the output of the following statement?list1 = [12, 32, 65, 26, 80, 10]
sorted(list1)
print(list1)

Accepted Answer

Output[12, 32, 65, 26, 80, 10]
ExplanationIn the given code, list1 is initialized as [12, 32, 65, 26, 80, 10]. The sorted(list1) function is called, which creates and returns a new list with the elements of list1 sorted in ascending order, but it does not modify the original list1. Since the sorted result is not stored or printed, the next line print(list1) outputs the original unsorted list [12, 32, 65, 26, 80, 10].

Question 10

Question 8(c)What will be the output of the following statement?list1 = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
list1[::-2]
list1[:3] + list1[3:]

Accepted Answer

Output[1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
ExplanationIn the given code, list1 is initialized as [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]. The expression list1[::-2] creates a new list with elements from list1 in reverse order, taking every second element, resulting in [10, 8, 6, 4, 2], but this new list is not stored or used further. The expression list1[:3] + list1[3:] concatenates the first three elements [1, 2, 3] with the rest of the elements [4, 5, 6, 7, 8, 9, 10].

Question 11

Question 8(d)What will be the output of the following statement?list1 = [1, 2, 3, 4, 5]
list1[len(list1)-1]

Accepted Answer

Output[1, 2, 3, 4, 5]
ExplanationIn the given code, list1 is initialized as [1, 2, 3, 4, 5]. The len(list1) returns the number of elements in the list, which is 5. The len(list1) - 1 evaluates to 4 (i.e., 5 - 1). The list1[len(list1) - 1] accesses the element at index 4, which is 5. However, since the result is not assigned to any variable or printed, it has no effect on the list.

Question 12

Question 9What will be the output of the following code segment?myList = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
for i in range(0, len(myList)):
   if i % 2 == 0:
      print (myList[i])

Accepted Answer

Output1
3
5
7
9
ExplanationIn the given code, myList is initialized as [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]. The for loop iterates over the range of indices from 0 to len(myList)-1. Inside the loop, the if statement checks if the current index i is even by using the modulus operator i % 2 == 0. If the condition is true (i.e., the index is even), it prints the element at that index in myList. As a result, the code prints all the elements at even indices, specifically: 1, 3, 5, 7, and 9.

Question 13

Question 10(a)What will be the output of the following code segment?myList = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
del myList[3:]
print(myList)

Accepted Answer

Output[1, 2, 3]
ExplanationIn the given code, myList is initialized as [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]. The del myList[3:] statement deletes all elements in the list starting from index 3 to the end. This modifies myList to only contain the elements from index 0 to 2. The subsequent print(myList) statement then outputs the modified list [1, 2, 3].

Question 14

Question 10(b)What will be the output of the following code segment?myList = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
del myList[:5]
print(myList)

Accepted Answer

Output[6, 7, 8, 9, 10]
ExplanationIn the given code, myList is initialized as [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]. The del myList[:5] statement deletes all elements in the list from the beginning up to, but not including, index 5. This removes the first five elements (1, 2, 3, 4, 5) from myList. The subsequent print(myList) statement then outputs the modified list, which is [6, 7, 8, 9, 10].

Question 15

Question 10(c)What will be the output of the following code segment?myList = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
del myList[::2]
print(myList)

Accepted Answer

Output[2, 4, 6, 8, 10]
ExplanationIn the given code, myList is initialized as [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]. The del myList[::2] statement deletes elements in the list with a step of 2, starting from the beginning of the list. This means, it removes every second element from myList. Specifically, it deletes elements at indices 0, 2, 4, 6, and 8, which correspond to the values 1, 3, 5, 7, and 9. The subsequent print(myList) statement then outputs the modified list, which is [2, 4, 6, 8, 10].

Question 16

Question 11Write the output of the following Python program code:Str2 = list("Cam@123*")
for i in range(len(Str2)-1):
   if i==5:
      Str2[i] = Str2[i]*2
   elif (Str2 [i].isupper()):
      Str2 [i] = Str2 [i]*2
   elif (Str2 [i].isdigit()):
      Str2 [i] = 'D'
print(Str2)

Accepted Answer

Output['CC', 'a', 'm', '@', 'D', '22', 'D', '*']
ExplanationIn the given code, Str2 is initialized as a list of characters from the string "Cam@123*", resulting in ['C', 'a', 'm', '@', '1', '2', '3', '*']. The for loop iterates over the indices of Str2 from 0 to len(Str2) - 1. Within the loop, three conditions modify the elements of Str2: if the index i is 5, the character at Str2[i] is multiplied by 2, if the character is uppercase, it is also multiplied by 2, if the character is a digit, it is replaced with 'D'. After the loop, Str2 becomes ['CC', 'a', 'm', '@', 'D', '22', 'D', '*'], which is printed as the final output.

Question 17

Question 12Differentiate between append() and extend() methods of list.

Accepted Answer

append()extend()The append() method adds a single item to the end of the list. The single element can be list, number, strings, dictionary etc.The extend() method adds one list at the end of another list.The syntax of append() method is list.append(item).The syntax of extend() method is list.extend(list1).For example:lst1 = [10, 12, 14]lst1.append(16)print(lst1)Output — [10, 12, 14, 16]For example:t1 = ['a', 'b', 'c']t2 = ['d', 'e']t1.extend(t2)print(t1)Output — ['a', 'b', 'c', 'd', 'e']

Question 18

Question 13Write a program to read a list of n integers (positive as well as negative). Create two new lists, one having all positive numbers and the other having all negative numbers from the given list. Print all three lists.Solutionn = int(input("Enter number of elements in the list: "))
nums = []

print("Enter the elements of the list:")
for i in range(n):
    n1 = int(input("Enter element: "))
    nums.append(n1)

positive = []
negative = []

for num in nums:
    if num < 0:
        negative.append(num)
    else:
        positive.append(num)

print("Original List:", nums)
print("Positive Numbers:", positive)
print("Negative Numbers:", negative)OutputEnter number of elements in the list: 6
Enter the elements of the list:
Enter element: 1
Enter element: -4
Enter element: 0
Enter element: -3
Enter element: 5
Enter element: 9
Original List: [1, -4, 0, -3, 5, 9]
Positive Numbers: [1, 0, 5, 9]
Negative Numbers: [-4, -3]

Accepted Answer

n=int(input("Enter number of elements in the list: "))nums=[]print("Enter the elements of the list:")foriinrange(n):n1=int(input("Enter element: "))nums.append(n1)positive=[]negative=[]fornuminnums:ifnum0:negative.append(num)else:positive.append(num)print("Original List:",nums)print("Positive Numbers:",positive)print("Negative Numbers:",negative)OutputEnter number of elements in the list: 6Enter the elements of the list:Enter element: 1Enter element: -4Enter element: 0Enter element: -3Enter element: 5Enter element: 9Original List: [1, -4, 0, -3, 5, 9]Positive Numbers: [1, 0, 5, 9]Negative Numbers: [-4, -3]

Question 19

Question 14Write a program to find the largest and the second largest elements in a given list of elements.Solutionnums = eval(input("Enter the list: "))

first = nums[0]
second = nums[0]

for num in nums[2:]:
    if num > first:
        second = first  
        first = num     
    elif num > second and num != first:
        second = num

print("Largest element:", first)
print("Second largest element:", second)OutputEnter the list: [2, 8, 10, 18, 15, 6]
Largest element: 18
Second largest element: 15

Accepted Answer

nums=eval(input("Enter the list: "))first=nums[0]second=nums[0]fornuminnums[2:]:ifnum>first:second=firstfirst=numelifnum>secondandnum!=first:second=numprint("Largest element:",first)print("Second largest element:",second)OutputEnter the list: [2, 8, 10, 18, 15, 6]Largest element: 18Second largest element: 15

Question 20

Question 15Write a program to read a list of n integers and find their median.Note: The median value of a list of values is the middle one when they are arranged in order. If there are two middle values, then take their average.Hint: Use an inbuilt function to sort the list.Solutionn = int(input("Enter number of elements in the list: "))
nums = []

print("Enter the elements of the list:")
for i in range(n):
    n1 = int(input("Enter element: "))
    nums.append(n1)
    
nums.sort()
n = len(nums)

if n % 2 == 0:
    mid1 = nums[n // 2 - 1]
    mid2 = nums[n // 2]
    median = (mid1 + mid2) / 2
else:
    median = nums[n // 2]

print("Median of the list is:", median)OutputEnter number of elements in the list: 6
Enter the elements of the list:
Enter element: 10
Enter element: 20
Enter element: 4
Enter element: 45
Enter element: 99
Enter element: 30
Median of the list is: 25.0

Enter number of elements in the list: 5
Enter the elements of the list:
Enter element: 3
Enter element: 7
Enter element: 9
Enter element: 5
Enter element: 11
Median of the list is: 7

Accepted Answer

n=int(input("Enter number of elements in the list: "))nums=[]print("Enter the elements of the list:")foriinrange(n):n1=int(input("Enter element: "))nums.append(n1)nums.sort()n=len(nums)ifn%2==0:mid1=nums[n//2-1]mid2=nums[n//2]median=(mid1+mid2)/2else:median=nums[n//2]print("Median of the list is:",median)OutputEnter number of elements in the list: 6Enter the elements of the list:Enter element: 10Enter element: 20Enter element: 4Enter element: 45Enter element: 99Enter element: 30Median of the list is: 25.0Enter number of elements in the list: 5Enter the elements of the list:Enter element: 3Enter element: 7Enter element: 9Enter element: 5Enter element: 11Median of the list is: 7

Lists in Python

Assertions And Reasons

Multiple Choice Questions

Solutions To Unsolved Questions