title: Python - matrix to dataframe, rename columns
body: <p>I have a matrix which is being converted into a dataframe. I have used,</p>
  
  <pre><code>Y_NEW2 = pd.DataFrame(data=Y_NEW).
  </code></pre>
  
  <p>The output by default give column names as 0 1 2 3 4 5 6 (I have 7 columns) as below</p>
  
  <pre><code>    **0    1    2    3    4         5    6**
   0  5.0  2.0  0.0  0.0  2.0  2.000000  1.0
   1  4.0  2.0  2.0  1.0  0.0  1.500000  2.0
   2  1.0  1.0  0.0  0.0  0.0  3.000000  3.0
   3  0.0  3.0  0.0  2.0  1.0  0.000000  7.0
   4  1.0  1.0  0.0  4.0  4.0  3.500000  0.0
   5  1.0  3.0  4.0  5.0  1.0  3.000000  3.0
   6  0.0  1.0  1.0  3.0  0.0  0.000000  5.0
   7  2.0  3.0  1.0  0.0  0.0  2.333333  0.0
   8  0.0  0.0  0.0  3.0  3.0  0.000000  0.0
   9  5.0  6.0  3.0  0.0  2.0  4.000000  6.0
  </code></pre>
  
  <p>How can I rename the columns to user1, user 2, user3, user4, user5, user6, user7?</p>