2016-11-10 12:58:12 +0200 received badge ● Student (source) 2016-11-09 22:00:46 +0200 asked a question How to create a row that displays the counts of column entries in a matrix using python/sage? so here is my matrix: A = matrix([[1,1,2,2,2], [3,1,4,3,3], [0,4,2,4,0], [0,0,2,0,0], [0,0,2,0,0]])  I would like to insert a 0 row that displays the amount of row entries in each column. This was my original code: A = matrix([[1,1,2,2,2], [3,1,4,3,3], [0,4,2,4,0], [0,0,2,0,0], [0,0,2,0,0]])  puzzle = A.insert_row(0, sum(A)) Whats wrong with this code is that it gives me the sum of each column, when I just need the count of each column. What I have [ 4 6 12 9 5] [ 1 1 2 2 2] [ 3 1 4 3 3] [ 0 4 2 4 0] [ 0 0 2 0 0] [ 0 0 2 0 0]  Desired [ 2 3 5 3 2] [ 1 1 2 2 2] [ 3 1 4 3 3] [ 0 4 2 4 0] [ 0 0 2 0 0] [ 0 0 2 0 0]