# []

tableau = [[-3, -1, 1, 0, 0, -3], [-2, -3, 0, -1, 0, -6], [2, 1, 0, 0, 1, 4], [-5, -2, 0, 0, 0]]
print(tableau)

pr_idx = 0
pc_idx = 1

tableau[pr_idx] = [a / tableau[pr_idx][pc_idx] for a in tableau[pr_idx]]

for i, row in enumerate(tableau[:-1]):
    if i != pr_idx:
        for j, a in enumerate(row):
            tableau[i][j] = tableau[pr_idx][j]