Given two lists containing sublists, the task is to merge elements of sublist of two lists in a single list.
Examples:
Input:
list1 = [[1, 20, 30],
[40, 29, 72],
[119, 123, 115]]
list2 = [[29, 57, 64, 22],
[33, 66, 88, 15],
[121, 100, 15, 117]]
Output: [[1, 20, 30, 29, 57, 64, 22],
[40, 29, 72, 33, 66, 88, 15],
[119, 123, 115, 121, 100, 15, 117]]
Method #1: Using Map + lambda
Python3
# Python code to merge elements of sublists# Initialisation of first listlist1 = [[1, 20, 30], [40, 29, 72], [119, 123, 115]]# Initialisation of second listlist2 = [[29, 57, 64, 22], [33, 66, 88, 15], [121, 100, 15, 117]]# Using map + lambda to merge listsOutput = list(map(lambda x, y:x + y, list1, list2))# Printing outputprint(Output) |
[[1, 20, 30, 29, 57, 64, 22], [40, 29, 72, 33, 66, 88, 15], [119, 123, 115, 121, 100, 15, 117]]
Time Complexity: O(n*n), where n is the length of the list test_list
Auxiliary Space: O(n) additional space of size n is created where n is the number of elements in the res list
Method #2: Using Zip()
Python3
# Python code to merge elements of sublists# Initialisation of first listlist1 = [[1, 20, 30], [40, 29, 72], [119, 123, 115]]# Initialisation of second listlist2 = [[29, 57, 64, 22], [33, 66, 88, 15], [121, 100, 15, 117]]# Using zip to merge listsOutput = [x + y for x, y in zip(list1, list2)]# Printing outputprint(Output) |
[[1, 20, 30, 29, 57, 64, 22], [40, 29, 72, 33, 66, 88, 15], [119, 123, 115, 121, 100, 15, 117]]
Method #3: Using starmap() and concat()
Python3
# Python code to merge elements of sublistsfrom operator import concatfrom itertools import starmap# Initialisation of first listlist1 = [[1, 20, 30], [40, 29, 72], [119, 123, 115]]# Initialisation of second listlist2 = [[29, 57, 64, 22], [33, 66, 88, 15], [121, 100, 15, 117]]# Using starmap() and concat to merge listOutput = list(starmap(concat, zip(list1, list2)))# Printing outputprint(Output) |
[[1, 20, 30, 29, 57, 64, 22], [40, 29, 72, 33, 66, 88, 15], [119, 123, 115, 121, 100, 15, 117]]
Method #4: Using inbuilt extend()
This code uses the zip function to iterate through list1 and list2 simultaneously. For each sublist in list1 and list2, it uses the extend method to add the elements of sublist2 to sublist1. The modified sublist1 is then appended to merged_list.
Python3
# Initialisation of first listlist1 = [[1, 20, 30], [40, 29, 72], [119, 123, 115]]# Initialisation of second listlist2 = [[29, 57, 64, 22], [33, 66, 88, 15], [121, 100, 15, 117]]# Merge elements of sublists using extend()merged_list = []for sublist1, sublist2 in zip(list1, list2): sublist1.extend(sublist2) merged_list.append(sublist1)# Print merged listprint(merged_list)#This code is contributed by Edula Vinay Kumar Reddy |
[[1, 20, 30, 29, 57, 64, 22], [40, 29, 72, 33, 66, 88, 15], [119, 123, 115, 121, 100, 15, 117]]
The time complexity of this code is O(n), where n is the total number of elements in list1 and list2. The space complexity is also O(n), as the merged_list will also have n elements.
