Basic List and List Comprehension Questions 
 
1. Create a list of Numbers from 0 to 50 using List comprehension. 
 
Numbers = [x for x in range(51)] it prints numbers from 0 to 50 
Numbers = [x for x in range(1,51)] it prints numbers from 1 to 50 
Numbers = [x for x in range(1,51,2)] it prints odd numbers from 0 to 50 
Numbers = [x for x in range(2,51,2)] it prints even numbers from 0 to 50 
 
2. Create a list of square of a number from 1 to 20. 
 
Square = [x**2 for x in range(21)] 
 
//squares using Null list and append method 
squares = [] 
 
for x in range(10): 
    # raise x to the power of 2 
    squares.append(x**2) 
 
print(squares) 
 
//squares using existing list and append method 
squares = [1,4,9,16,25] 
 
for x in range(6,11): 
    # raise x to the power of 2 
    squares.append(x**2) 
 
print(squares) 
 
3. Create a list of 10 characters and make a slice of list from character 4 to 8. 
 
Char = [“A”,”B”,”C”, “D”,”E”,”F”, “G”,”H”,”I”,”J”] 
Slice = Char[3:8] 
 
4. Give the differences between list insert and list append with suitable examples. 
 
Char = [“A”,”B”,”C”, “D”,”E”,”F”, “G”,”H”,”I”,”J”] 
Char.append(“k”) 
print(Char) it append value K at last position 
Char.insert(0,”a”) 
Print(Char)  It insert value at desired index 
 
 
5. Create two list and combine / merge them using list extend method and 
concatenation operator. 
 
L = ['red', 'green', 'yellow'] 
M = [1,2,3] 
L.extend(M) 
print(L) 
 
6. Create a list of subject names L = [“EPR”, “EPA”,”FEP”, “BMA”, “FOM”,’’OS”] 
A. Remove “BMA” using index and store it in another variable. 
B. Remove “OS” by value. 
 
L = [“EPR”, “EPA”,”FEP”, “BMA”, “FOM”,’’OS”] 
x = L.pop(3) 
print(L) 
print(x) 
 
L.remove(“OS”) 
Print(L) 
 
7. Create a list which prints only even numbers from 0 to 25. 
 
Numbers = [x for x in range(2,25,2)] it prints even numbers from 0 to 25 
 
8. Create a list of numbers from 0 to 10 and multiply all numbers using 5 using list 
comprehension. 
 
multiply = [x*5 for x in range(11)] 
 
9. Create a list L = [“EPR”, “EPA”,”FEP”, “BMA”, “FOM”,’’OS”] and create a new list which 
has first letter of each subjects. 
 
L = ["EPR","EPA","FEP","BMA","FOM","OS"] 
 
letters = [ name[0] for name in L ] 
print(letters) 
 
letters = [ name[1] for name in L ] 
print(letters) 
 
10. Use list comprehension to separate characters in a string and store it in list. 
 
letters = [ letter for letter in "embedded programming"] 
print(letters) 
 
 
 
11. Create following list  
L = [‘a’,’b’,’c’,’d’,’e’]  
M=[‘P’,’Q’,’R’,’S’,’T’] 
1. Convert all lower case to upper from list L. 
2. Convert all upper case to lower from list M. 
 
L = ['a','b','c','d','e'] 
M = ['P','Q','R','S','T'] 
upper_case = [ letter.upper() for letter in L ] 
lower_case = [ letter.lower() for letter in M ] 
 
print(upper_case, lower_case) 
 
12. Create a string with your name and phone number, Separate out phone number’s 
digit from the string. 
X = “My number is 9898989898.” 
 
X = “My number is 9898989898.” 
phone_number = [ a for a in x if a.isdigit()] 
 
print(phone_number) 
 
13. Create a text file which has email addresses of a student in each line. Open the file in 
read mode and print all lines in python. 
 
file = open("E:\list.txt", 'r') 
email = [ line for line in file ] 
 
for x in email: 
    print(x) 
 
14. Create a list  
1. to double a number from 1 to 10 using function and list comprehension. 
2. to double only even numbers from 1 to 10 using function and list comprehension. 
 
def double(x): 
    return x*2 
 
nums = [double(x) for x in range(1,11)] 
print(nums) 
 
nums = [double(x) for x in range(1,11) if x%2 == 0] 
print(nums) 
 
 
 
 
15. Create two list of numbers (same size) and add all possible combination of numbers 
from list using list comprehension. 
L=[1,2,3,4,5] 
M=[10,20,30,40,50] 
 
L=[1,2,3,4,5] 
M=[10,20,30,40,50] 
addition = [x+y for x in L for y in M ] 
print(addition) 
 
16. Count a number of occurrence from the list. 
1. Count how many times 9 occurs in the list L = [9,1,2,9,2,9,9,3,4] 
2. Count how many times ‘red’ occurs in the list M = [‘red’, ‘red’,’blue’,’yellow’] 
 
L=[9,1,2,9,2,9,9,3,4] 
x=L.count(9) 
print(x) 
 
M=['red','red','blue','yellow','red'] 
y=M.count('red') 
print(y) 
 
17. Count all the items from the list using counter() function. 
L=[9,2,2,3,3,4,4,5,5,5,9,9,9,2] 
 
L=[9,2,2,3,3,4,4,5,5,5,9,9,9,2] 
from collections import Counter 
print(Counter(L)) 
 
18. Reverse the list items for the following list. 
L=[1,2,3,4,5,6,7,8,9] 
M=[‘a’,’b’,’c’,’d’,’e’] 
 
L=[1,2,3,4,5,6,7,8,9] 
M=['a','b','c','d','e'] 
L.reverse() 
M.reverse() 
print(L) 
print(M) 
print(L,M) 
 
19. Access each list items for the following list in reversed order. 
L=[1,2,3,4,5,6,7,8,9] 
M=[‘a’,’b’,’c’,’d’,’e’] 
 
L=[1,2,3,4,5,6,7,8,9] 
M=['a','b','c','d','e'] 
 
for x in reversed(L): 
    print(x) 
for y in reversed(M): 
    print(y) 
 
20.  Reverse the following list and then Sort the list  
L=[1,2,3,3,5,3,2,8,1] 
 
L=[1,2,3,3,5,3,2,8,1] 
L.reverse() 
L.sort() 
print(L) 
(Python does not differentiate between numbers and strings while sorting.) 
 
21. Sort the list in reverse order. 
L=[1,2,3,3,5,3,2,8,1] 
 
L=[1,2,3,3,5,3,2,8,1] 
L.sort(reverse=True) 
print(L) 
 
22. Sum all the elements of a list. 
L=[1,2,3,3,5,3,2,8,1] 
 
L=[1,2,3,3,5,3,2,8,1] 
x=sum(L) 
print(x) 
 
23. What is the use of following command? 
print(L[::-1]) if L=[1,2,3,3,5,3,2,8,1] 
 
v L=[1,2,3,3,5,3,2,8,1] 
print(L[::-1]) 
It prints the List in Reverse Order. 
 
24. How to insert items at the end of the list using len() function? 
L=[‘a’,’b’,’c’] and items to be inserted at the is [1,2,3,4,5] 
 
L=[‘a’,’b’,’c’] 
L[len(L):] = [1,2,3,4,5] 
Print(L) 
 
 
 
 
 
25. Insert value= 4 at index 2 in the following list without insert() or append() method. 
To be inserted=[1,2,3,4,5] in the list L=['a','b','c'] 
 
L=['a','b','c'] 
L[2:2] = [1,2,3,4,5] 
print(L) 
 
26. Given list is L = ['a', 'b', 'c', 'd', 'e']. Delete items from index 1 to 3 without delete(), pop() or 
del() functions 
 
L = ['a', 'b', 'c', 'd', 'e'] 
L[1:4] = [] 
Print(L) 
 
27. What is the output of the following commands? 
L1 = ['a', 'b', 'c', 'd', 'e'] 
L2 = L1[:] 
 
It will copy the list L1 to L2. Their locations are different so L1 is not equal to L2. 
 
28. Create a list with absolute values of given list 
L=[-4,-4,-3,-2,0,1,2,3,-4] 
 
L=[-4,-4,-3,-2,0,1,2,3,-4] 
Absolute = [abs(x) for x in L] 
print(Absolute) 
 
29. How to remove the whitespace added with following list items? 
colors = ['    red', '    green ', 'blue    '] 
 
Use strip() function to remove the whitespace as follows. 
 
colors = ['  red', '  green ', 'blue  '] 
L = [x.strip() for x in colors] 
print(L) 
 
30. why you should use list comprehension more often? 
 
 List comprehensions are more concise to write and hence they turn out to be very 
useful in many contexts. 
 Since a list comprehension is an expression, you can use it wherever you need an 
expression (e.g. as an argument to a function, in a return statement). 
 List comprehensions run substantially faster than manual for loop statements 
(roughly twice as fast).  
 It offers a major performance advantage especially for larger data sets. 
 
 
31. Print only positive numbers from the list given below. 
L=[-4,-4,-3,-2,0,1,2,3,-4] 
 
 
 
32. How to convert List L=[1,2,3] into Tuple? 
 
L=[1, 2, 3] 
T = tuple(L) 
print(T) 
 
33. How to convert string ‘abcd’ into tuple? 
 
T = tuple('abcd') 
print(T) 
 
34. With example explain the concepts of Tuple Packing and Tuple Unpacking. 
 
T = ('red', 'green', 'blue', 'cyan') 
print(T) 
(a, b, c, d) = T 
print(a) 
print(b) 
print(c) 
print(d) 
 
35. Swap two numbers a=10, b=20 using concept of Python Tuple. 
 
a=10 
b=20 
print(a) 
print(b) 
b,a = a,b 
print(a) 
print(b) 
 
 
36. Split an email address [email protected] into a user name and a domain using Python 
Tuple. 
 
email = '[email protected]' 
user,domain=email.split('@') 
print(user) 
print(domain) 
 
 
 
37. Create a tuple and access the items of tuple using negative indexing. 
 
T = ('red', 'green', 'blue', 'yellow', 'black') 
 
print(T[-5]) 
print(T[-4]) 
print(T[-3]) 
print(T[-2]) 
print(T[-1]) 
 
38. Explain Tuple slicing with example. 
 
T = ('a', 'b', 'c', 'd', 'e', 'f') 
print(T[2:5]) 
# Prints ('c', 'd', 'e') 
print(T[0:2]) 
#Prints(‘a’,’b’) 
 
39. Can you change the value of the following tuples. Justify 
1. T = (‘a’,’b’,’c’) change value b 
2. T = (1, [2, 3], 4)change value 2 
 
 
1. Value of b cannot be edited because Tuple is immutable. 
2. Value of 2 in the list can be changed because List inside the tuple is mutable. 
T = (1, [2, 3], 4) 
T[1][0] = 'EPR' 
print(T) 
# It prints T = (1, [‘EPR’, 3], 4) 
 
 
40. Sort the following tuple T = ('cc', 'aa', 'dd', 'bb') 
 
Print(Tuple(sorted(T)))