Interview question

Why does changing one element change all the inner lists in this Python example? l = [[0]] * 10 print(l) # [[0], [0], [0], [0], [0], [0], [0], [0], [0], [0]] l[0][0] = 1 print(l) # [[1], [1], [1], [1], [1], [1], [1], [1], [1], [1]]