test_a = np.asarray([1, 5, 6])
test_b = np.asarray([0.1, 0.2, 0.3])
print('filter out = ', (test_b <= 0.2) * test_b) # [0.1, 0.2, 0]
test_a[test_b <= 0.2] = 10 # [10, 10, 6]
test_a[[True, False, True]] = 123 # [123, 10, 123]
test_a[np.asarray([1, 2])] = 456 # [123, 456, 456]