Complete the function sparse_matrix in the t05_functions.py module. The module t05.py provides simple testing for this function.

A sparse matrix is a matrix that typically is very large but contains very little non-zero data. Rather than store the zeroes the sparse matrix stores the row and column location of only the non-zero values. This function converts a file, where each line of the file represents a row in the resulting matrix, into a 2D Python list whose contents are of the form:

[[row, col, value], [row, col, value], ...] 

The sample file sparse1.txt contains:

0,0,0,0,0,0,0,0,6,0,0 0,0,0,9,0,0,0,0,0,0,0 0,2,0,0,0,0,0,4,0,0,0 0,0,0,0,0,0,7,0,0,0,0 

which becomes:

[[0, 8, 6], [1, 3, 9], [2, 1, 2], [2, 7, 4], [3, 6, 7]] 

Thus: [0, 8, 6] is row 0, column 8, value 6; [1, 3, 9] is row 1, column 3, value 9; etc.

Some examples from executing t05.py against sparse2.txt and sparse3.txt:

f_in = open('sparse2.txt', "r", encoding="utf-8") matrix = sparse_matrix(f_in) fh_in.close()

[] 

f_in = open('sparse3.txt', "r", encoding="utf-8") matrix = sparse_matrix(f_in) fh_in.close()

[[0, 0, 12], [0, 1, 13], [0, 2, 14]] 

Requirements

This function must:

Return, not print, the resulting 2D list