title: __repr__() returned non-string
body: <p>So I have a class method with which I would like to draw out the dictionary and it's values:</p>
  
  <pre><code> def __repr__ (self): 
          for row in zip(*([ky]+map(str,val) for ky,val in (self.slovar.items()))):
  
             print"\t".join (row)
  </code></pre>
  
  <p>If it's like this, I get a desired output:</p>
  
  <pre><code>&gt;&gt;&gt; test
  n   n1  n2
  1   a   2.3
  2   b   2.1
  3   d   2.5
  
  Traceback (most recent call last):
    File "&lt;pyshell#521&gt;", line 1, in &lt;module&gt;
      test
  TypeError: __repr__ returned non-string (type NoneType)
  </code></pre>
  
  <p>but also a Traceback error.</p>
  
  <p>If I return the value instead of printing it out, I only get this:</p>
  
  <pre><code>&gt;&gt;&gt; test
  n   n1  n2
  </code></pre>
  
  <p>It works fine if I make a custom method not the default 'system' one... (and I need it to be default)</p>