In this post, we will learn the 25 List Programming interview questions and answers.
1.Program to find the max, min number from the list user input.
listlang = []
numbers = int(input('enter the number of items in list '))
for num in range(numbers):
item = int(input('Entered number '))
listlang.append(item)
print('entered list =',listlang)
print("Max number = :", max(listlang), "\nMin number :", min(listlang))
Output
enter the number of items in list 4
Entered number 12
Entered number 34
Entered number 45
Entered number 67
entered list = [12, 34, 45, 67]
Max number = : 67
Min number : 12
2. Code to remove duplicate from list using List comprehension
lstnum = [12, 36, 56, 36, 36, 50, 56, 12]
unique_lst = []
[unique_lst.append(ele) for ele in lstnum if ele not in unique_lst]
print ("unique elements list : " ,unique_lst)
Output
unique elements list : [12, 36, 56, 50]
3. Program to find the sum of list elements.
lstnum = [12, 36, 56, 36, 36, 50, 56, 12]
sum = 0
for ele in range(0, len(lstnum)):
sum = sum + lstnum[ele]
print ("sum of list items: " ,sum)
Output
sum of list items : 294
4. How to Multiply all the elements of list
lstnum = [6, 2, 3, 1, 10, 4]
mutiply =1;
for ele in lstnum:
mutiply = mutiply* ele
print ("multiplication of list items : " ,mutiply)
Output
multiplication of list items : 1440
5.Program to generate a number list between two ranges.
listnum = list(range(1, 7))
print ("list between two range : " ,listnum)
Output
list between two range : [1, 2, 3, 4, 5, 6]
6.How to reverse the List using slice
listnum = [45,67,12,14,56,87]
reverselist =listnum[::-1]
print ("reverselist : " ,reverselist)
Output
reverselist : [87, 56, 14, 12, 67, 45]
7.How to flatten a list of lists with a list comprehension
listnum = [[5,6,7,'C#'], ['C++',2,3]]
flatten_list = [ele for sublist in listnum for ele in sublist]
print('flatten list =',flatten_list)
Output
flatten list = [5, 6, 7, 'C#', 'C++', 2, 3]
8.How to Intersect two list
listnum = ['C++',2,3,6,7,5,'C#']
listnum1 = ['C++',5,6,7,'C#']
intersect_res = [item for item in listnum if item in listnum1]
print('intersect of two list =',intersect_res)
Output
intersect of two list = ['C++', 6, 7, 5, 'C#']
9.Program to shuffle a list and print
from random import shuffle
listnum = ['Rust','go','C++',2,3,6,7,5,'C#']
shuffle(listnum)
print('list after shuffling =',listnum)
Output
list after shuffling = [6, 5, 'go', 'C#', 2, 3, 'Rust', 7, 'C++']
10. Program to convert a list into string
listlang = ['This','is','list','Code']
listtostring = ' '.join(listlang)
print('list after shuffling =',listtostring)
Output
list after shuffling = This is list Code
11.How to get the square of each list element between two range
listnum = list(range(3,9))
list_item_square = [ele ** 2 for ele in listnum]
print(list_item_square)
Output
[9, 16, 25, 36, 49, 64]
12. Program to get the difference between two List using comprehension
lstnum = [15, 78, 4]
lstnum1 = [80, 4, 89]
two_list_differnce = [ele for ele in lstnum if ele not in lstnum1]
print(two_list_differnce)
Output
[15, 78]
13. How to count the number of list in list of list.
lstlng = [[15, 78, 4],['C#',80,7],['Go','Rust','C++'],['Python',12]]
print('count of list of list = ',len(lstlng))
Output
count of list of list = 4
14. How to get the first element from each nested list of a list
lstlng = [[15, 78, 4],['C#',80,7],['Go','Rust','C++'],['Python',12]]
each_list_element = [item[0] for item in lstlng]
print('first element of each nested list = ',each_list_element)
Output
first element of each nested list = [15, 'C#', 'Go', 'Python']
15. How to count occurrence of repeated element in list
from collections import Counter
lstlng = [15, 18, 14,'C#',18,15,'C#','C++','C++','Python',15]
repeation_of_element = Counter(lstlng)
print( repeation_of_element)
Output
Counter({15: 3, 18: 2, 'C#': 2, 'C++': 2, 14: 1, 'Python': 1})
16. How to Filter even values from a list using list comprehension
lstnum = [12, 18, 14,18,15,6]
even_element_list = [ele for ele in lstnum if ele%2 == 0]
print('even item list =',even_element_list)
Output
even item list = [12, 18, 14, 18, 6]
17.How to Sort a list of integers in descending order
lstnum = [12, 18, 14,25,15,6]
lstnum.sort(reverse=True)
print('list sorting in descending order =',lstnum)
Output
list sorting in descending order = [25, 18, 15, 14, 12, 6]
18.How to Sort a list of integers in ascending order
sort() method used to sort the list in ascending order.
lstnum = [12, 18, 14,25,15,6]
lstnum.sort()
print('list sorting in ascending order =',lstnum)
Output
list sorting in ascending order = [6, 12, 14, 15, 18, 25]
19. How to remove elements in a list before a specific index
lstnum = [12, 18, 14,25,15,6]
new_list = lstnum[4:]
print('removinfg element before specific Index =' ,new_list)
Output
removing element before specific Index = [15, 6]
20.How to remove empty strings from the list of strings
liststr = ["Python", "", "list", "first", "", "example"]
lstafter_remove_empty = list(filter(None, liststr))
print(lstafter_remove_empty)
Output
['Python', 'list', 'first', 'example']
21.How to sort two lists simultaneously
lstnum = [ 5,2, 1, 7,26]
lstnum1 = [45,35, 78, 80, 100]
lstnum, lstnum1 = zip(*sorted(zip(lstnum, lstnum1)))
print(lstnum, lstnum1)
Output
(1, 2, 5, 7, 26) (78, 35, 45, 80, 100)
23.How to concatenate two list element wise/index-wise.
lststr = ["th", "i", "Pyth", "exa"]
lststr1 = ["is", "s", "on", "mple"]
concate_list = [i + j for i, j in zip(lststr, lststr1)]
print('concatenated list = ',concate_list)
Output
concatenated list = ['this', 'is', 'Python', 'example']
24. How to concatenate every element across lists using list comprehension
lststr = ["this", "Python"]
lststr1 = ["is", "example", "of"]
templst = [(x, y) for x in lststr for y in lststr1]
concate_list = [x + ' ' + y for (x, y) in templst]
print('concatenated list = ',concate_list)
Output
concatenated list = ['this is', 'this example', 'this of', 'Python is', 'Python example', 'Python of']
25.How to remove negative values from a list with the filter function
lstnum = [-5, 27, 1000, -4, 0, -80,56,-67]
//Removing negative values
res_lst = [item for item in lstnum if item >= 0]
print('list after removing negative values =',res_lst)
Output
list after removing negative values = [27, 1000, 0, 56]