Python | Non-Repeating value Summation in Matrix

Sometimes we need to find the unique values in a list, that is comparatively easy and its summation and has been discussed earlier. But we can also get a matrix as input i.e a list of lists, finding unique in them are discussed in this article. Let’s see certain ways in which this can be achieved.

Method #1 : Using set() + list comprehension + sum()
The set function can be used to convert the individual list to a non-repeating element list and the list comprehension is used to iterate to each of the lists. The task of performing summation is performed using sum().

# Python3 code to demonstrate
# Non-Repeating value Summation in Matrix
# set() + list comprehension + sum()

# initializing matrix
test_matrix = [[1, 3, 1], [4, 5, 3], [1, 2, 4]]

# printing the original matrix
print ("The original matrix is : " + str(test_matrix))

# using set() + list comprehension + sum()
# Non-Repeating value Summation in Matrix
res = sum(list(set(i for j in test_matrix for i in j)))

# printing result
print ("Unique values summation in matrix are : " + str(res))

Output :

The original matrix is : [[1, 3, 1], [4, 5, 3], [1, 2, 4]]
Unique values summation in matrix are : 15

Method #2 : Using chain() + set() + sum()
The chain function performs the similar task that a list comprehension performs but in a faster way as it uses iterators for its internal processing and hence faster. The task of performing summation is performed using sum().

# Python3 code to demonstrate
# Non-Repeating value Summation in Matrix
# chain() + set() + sum()
from itertools import chain

# initializing matrix
test_matrix = [[1, 3, 1], [4, 5, 3], [1, 2, 4]]

# printing the original matrix
print ("The original matrix is : " + str(test_matrix))

# using chain() + set() + sum()
# Non-Repeating value Summation in Matrix
res = sum(list(set(chain(*test_matrix))))

# printing result
print ("Unique values summation in matrix are : " + str(res))

Output :

The original matrix is : [[1, 3, 1], [4, 5, 3], [1, 2, 4]]
Unique values summation in matrix are : 15