[[float(c) for c in row] for row in data]
[int(x) for line in data for x in line.split()]
dx = [3, 4, 5, 9]
dy = [5, 3, 2, 1]
output_matrix = []
for dx_n in dx:
dx_row = []
for dy_n in dy:
dx_row.append(dx_n * dy_n)
output_matrix.append(dx_row)
# Output is [[15, 9, 6, 3], [20, 12, 8, 4], [25, 15, 10, 5], [45, 27, 18, 9]]