Sort Matrix by Maximum Row Element in Python

When it is required to sort matrix by maximum row element, a method is defined that takes one parameter and uses ‘max’ method to determine the result.

Example

Below is a demonstration of the same −

def sort_max(row):
   return max(row)

my_list = [[15, 27, 18], [39, 20, 13], [13, 15, 56], [43, 13, 25]]

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

my_list.sort(key = sort_max, reverse = True)

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

Output

The list is :
[[15, 27, 18], [39, 20, 13], [13, 15, 56], [43, 13, 25]]
The result is :
[[13, 15, 56], [43, 13, 25], [39, 20, 13], [15, 27, 18]]

Explanation

• A method named ‘sort_max’ is defined that takes row as a parameter, and returns maximum element of row as output.

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

• The list is sorted using ‘sort’ method and the key is specified as the previously defined method.

• In addition to this, the ‘reverse’ parameter in ‘sort’ method is set to ‘True’ so that the list is reverse sorted.

• This is the output that is displayed on the console.