Hi, The following example shows what I want to do: >>> test rec.array([(0, 0, 0), (0, 0, 0), (0, 0, 0), (0, 0, 0), (0, 0, 0), (0, 0, 0), (0, 0, 0), (0, 0, 0), (0, 0, 0), (0, 0, 0)], dtype=[('ifAction', '|i1'), ('ifDocu', '|i1'), ('ifComedy', '|i1')]) >>> test[['ifAction', 'ifDocu']][0] (0, 0) >>> test[['ifAction', 'ifDocu']][0] = (1,1) >>> test[['ifAction', 'ifDocu']][0] (0, 0) So, I want to assign the values (1,1) to test[['ifAction', 'ifDocu']][0]. (Eventually, I want to do something like test[['ifAction', 'ifDocu']][0:10] = (1,1), assigning the same values for for 0:10. I have tried many ways but never succeeded. Is there any way to do this? Thank you, Joon