Given a Matrix, perform sort based upon the sum of rows.
Input : test_list = [[4, 5], [2, 5, 7], [2, 1], [4, 6, 1]]
Output : [[2, 1], [4, 5], [4, 6, 1], [2, 5, 7]]
Explanation : 3 < 9 < 11 < 14. Sorted sum.Input : test_list = [[4, 5], [2, 5, 7], [4, 6, 1]]
Output : [[4, 5], [4, 6, 1], [2, 5, 7]]
Explanation : 9 < 11 < 14. Sorted sum.
Method #1 : Using sort() + sum()
In this, task of sorting is done using sort(), and computation of sum is done by sum(), and passed as key fnc. to sort().
Python3
# Python3 code to demonstrate working of # Sort Matrix by row sum # Using sort() + sum() # helper_fnc def sum_sort(row): # getting sum return sum(row) # initializing list test_list = [[4, 5], [2, 5, 7], [2, 1], [4, 6, 1]] # printing original list print("The original list is : " + str(test_list)) # using sort() to perform sort test_list.sort(key = sum_sort) # printing result print("Sum sorted Matrix : " + str(test_list)) |
Output:
The original list is : [[4, 5], [2, 5, 7], [2, 1], [4, 6, 1]]
Sum sorted Matrix : [[2, 1], [4, 5], [4, 6, 1], [2, 5, 7]]
Method #2 : Using sorted() + sum() + lambda
In this, the task of sorting is done using sorted() and lambda is used in place of the external function call for the key.
Python3
# Python3 code to demonstrate working of # Sort Matrix by row sum # Using sorted() + sum() + lambda # initializing list test_list = [[4, 5], [2, 5, 7], [2, 1], [4, 6, 1]] # printing original list print("The original list is : " + str(test_list)) # using lambda fnction preventing fnc. call res = sorted(test_list, key=lambda row: sum(row)) # printing result print("Sum sorted Matrix : " + str(res)) |
Output:
The original list is : [[4, 5], [2, 5, 7], [2, 1], [4, 6, 1]]
Sum sorted Matrix : [[2, 1], [4, 5], [4, 6, 1], [2, 5, 7]]
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