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Python: Sort a given matrix in ascending order according to the sum of its rows using lambda

Python Lambda: Exercise-30 with Solution

Write a Python program to sort a given matrix in ascending order according to the sum of its rows using lambda.

Sample Solution:

Python Code :

def sort_matrix(M):
    result = sorted(M, key=lambda matrix_row: sum(matrix_row)) 
    return result

matrix1 = [[1, 2, 3], [2, 4, 5], [1, 1, 1]]
matrix2 = [[1, 2, 3], [-2, 4, -5], [1, -1, 1]]

print("Original Matrix:")
print(matrix1)
print("\nSort the said matrix in ascending order according to the sum of its rows") 
print(sort_matrix(matrix1))
print("\nOriginal Matrix:")
print(matrix2) 
print("\nSort the said matrix in ascending order according to the sum of its rows") 
print(sort_matrix(matrix2))

Sample Output:

Original Matrix:
[[1, 2, 3], [2, 4, 5], [1, 1, 1]]

Sort the said matrix in ascending order according to the sum of its rows
[[1, 1, 1], [1, 2, 3], [2, 4, 5]]

Original Matrix:
[[1, 2, 3], [-2, 4, -5], [1, -1, 1]]

Sort the said matrix in ascending order according to the sum of its rows
[[-2, 4, -5], [1, -1, 1], [1, 2, 3]]

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Python: Tips of the Day

Python: Cache results with decorators

There is a great way to cache functions with decorators in Python. Caching will help save time and precious resources when there is an expensive function at hand.

Implementation is easy, just import lru_cache from functools library and decorate your function using @lru_cache.

from functools import lru_cache

@lru_cache(maxsize=None)
def fibo(a):
    if a <= 1:
        return a
    else:
        return fibo(a-1) + fibo(a-2)

for i in range(20):
    print(fibo(i), end="|")

print("\n\n", fibo.cache_info())

Output:

0|1|1|2|3|5|8|13|21|34|55|89|144|233|377|610|987|1597|2584|4181|

 CacheInfo(hits=36, misses=20, maxsize=None, currsize=20)