title: python str != str not gives expected results
body: <p>I have two data files:</p>
  
  <p>file1 (815 lines):</p>
  
  <pre><code> 1    2    3     a 
   2    3    3     b
   1    2    2     b
  </code></pre>
  
  <p>file2 (1200 lines):</p>
  
  <pre><code> 2    5     5    a
   2    1     1    b
   1    2     2    c
  </code></pre>
  
  <p>What I want in output is the following:</p>
  
  <pre><code>  1    2     2    c
  </code></pre>
  
  <p>This is supposed to be the line from file2 which differs in the last column from file1 (you will notice that in the first two lines the last column is identical in both files); no matter what values first three columns contain, if the last column is unique, print that line.</p>
  
  <p>I am naively trying to do it with the following (python3) code but unsuccessful, so far, please guide. Thanks </p>
  
  <pre><code>with open(file1,'rU') as ij:
      for i in ij:
          i = i.rstrip().split('\t')
          with open(file2,'rU') as ji:
              for j in ji:
                  j = j.rstrip().split('\t')
                  if str(i[-1]) != str(j[-1]):
                      print(j)
  </code></pre>
  
  <p>With this method I am printing following:</p>
  
  <pre><code>2    3     3   b                                                                                                            
  4    2     3   c
  </code></pre>