Sort Matrix Rows by Summation of Consecutive Difference of Elements in Python

Example

Below is a demonstration of the same

def diff_summation_elem(row):
   return sum([abs(row[index + 1] - row[index]) for index in range(0, len(row) - 1)])

my_list = [[97, 6, 47, 3], [6, 88, 3, 26], [71, 53, 34, 65], [15, 36, 5,62]]

print("The list is : ")
print(my_list)

my_list.sort(key=diff_summation_elem)

print("The resultant list is :" )
print(my_list)

Output

The list is :
[[97, 6, 47, 3], [6, 88, 3, 26], [71, 53, 34, 65], [15, 36, 5, 62]]
The resultant list is :
[[71, 53, 34, 65], [15, 36, 5, 62], [97, 6, 47, 3], [6, 88, 3, 26]]

Explanation

• A method named ‘diff_summation_elem’ is defined that takes a list as a parameter.

• It uses the ‘abs’ method and the ‘sum’ method along with list comprehension to iterate over the list and get specific index values.

• Outside the method, a list of list is defined and is displayed on the console.

• The list is sorted based on the key being the method (previously defined).

• The output is displayed on the console.