Multiply matrix without NumPy - Would you let me know the code logic ?

Question

Would you please let me know the reason of writing lines 8 ,15 and 16 ?
I mean the exact logic behind this 3 lines

https://code.sololearn.com/c0wxdzUmSbtD/#py

Answer 1

Line 8 -- initializes the first row of the final output matrix with all zeros.

Line 15 -- calculates the product at the intersection of the k-th row and k-th column and adds the element to the output matrix (element-wise multiplication)

Line 16 -- actually assigns the result of line 15 to the respective cell of the matrix