title: How to fix this error when take data in Python
body: <p>The problem here that when I put in user='U3' and debugging I see <strong>history1[:, 1][i1][j1]</strong> and <strong>transactions1[:, 0][m]</strong> have the same value. That is ['T500'] but the expression return false (also ['T600']) and when they are have value ['T1000'], they return true. And the last output is ['I1', 'I3', 'I2'] instead of ['I1', 'I3', 'I2', 'I3', 'I1', 'I3', 'I2']. Please give me some
  advice to fix this.</p>
  <p>Thank for support</p>
  <pre><code>    def createMatrix(user, transactions1, history1):
          temp = []
          for i1 in range(len(history1[:, 0])):
              if history1[:, 0][i1] == user:
                  for j1 in range(len(history1[:, 1][i1])):
                      for m in range(len(transactions1[:, 0])):
                          if history1[:, 1][i1][j1] == transactions1[:, 0][m]: #&lt;------ Problem here
                              for item in transactions1[:, 1][m]: 
                                  temp.append(item)
          
          listNew = dict(zip(*np.unique(temp, return_counts=True)))
          return temp
  </code></pre>
  <p>Argument: transactions1</p>
  <pre><code>[[array(['T100'], dtype='&lt;U4') array(['I1', 'I2', 'I5'], dtype='&lt;U2')]
   [array(['T200'], dtype='&lt;U4') array(['I2', 'I4'], dtype='&lt;U2')]
   [array(['T300'], dtype='&lt;U4') array(['I2', 'I3'], dtype='&lt;U2')]
   [array(['T400'], dtype='&lt;U4') array(['I1', 'I2', 'I4'], dtype='&lt;U2')]
   [array(['T500'], dtype='&lt;U4') array(['I1', 'I3'], dtype='&lt;U2')]
   [array(['T600'], dtype='&lt;U4') array(['I2', 'I3'], dtype='&lt;U2')]
   [array(['T700'], dtype='&lt;U4') array(['I1', 'I3'], dtype='&lt;U2')]
   [array(['T800'], dtype='&lt;U4') array(['I1', 'I2', 'I3', 'I5'], dtype='&lt;U2')]
   [array(['T900'], dtype='&lt;U4') array(['I1', 'I2', 'I3'], dtype='&lt;U2')]
   [array(['T1000'], dtype='&lt;U5') array(['I1', 'I3', 'I2'], dtype='&lt;U2')]]
  </code></pre>
  <p>Argument: history1</p>
  <pre><code>[[array(['U1'], dtype='&lt;U2') array(['T100', 'T400'], dtype='&lt;U4')]
   [array(['U2'], dtype='&lt;U2') array(['T200', 'T300', 'T700'], dtype='&lt;U4')]
   [array(['U3'], dtype='&lt;U2') array(['T500 ', 'T600 ', 'T1000'], dtype='&lt;U5')]
   [array(['U4'], dtype='&lt;U2') array(['T800'], dtype='&lt;U4')]
   [array(['U5'], dtype='&lt;U2') array(['T900'], dtype='&lt;U4')]]
  </code></pre>