def usecase4(x, N):
 for k in range(N):
  y = x[k]
  print(y.f1, x.s1[k], y.f2)

def usecase4 ( x , N ) : for k in range ( N ) : y = x [ k ] print ( y . f1 , x . s1 [ k ] , y . f2 )
base on test3 of URL .