title: Array index for an ordered pair
body: <p>Hi I need create a ordered pair using this logic (no functions):</p>
  <pre><code>#---------------------------------------------------------------------------------
  
  A = [2,5,7];
  B = [6,2];
  LA = len(A)
  LB = len(B)
  Maux = [];
  print(type(Maux))
  
  for i in range(0,LA,1):
      for j in range(0,LB,1):
          
          Maux[i-1*LB + j , j] = [A[i] , B[j]] 
  
  print(Maux);
  
  #---------------------------------------------------------------------------------
  </code></pre>
  <p>When I compile the system says: list indices must be integers or slices, not tuple</p>
  <p>I read about this problem and I think is an incorrect index to access the matrix.</p>
  <p>Any idea?</p>