title: Change name of index column in pandas
body: <p>im curious if I can change the name of my very first column which is counting auto incrementally the index.</p>
  <p>I saw that you can change the name of the first column which is called <code>Unnamed 0</code> with this code
  <code>df_new.rename( columns={'Unnamed: 0':'newName'}, inplace=True )</code></p>
  <p>but this time there is no name which is called <code>Unnamed 0</code></p>
  <p>this is my output</p>
  <pre><code>      VPN Code    pid  VTS/VTA  ...  BSCL52_BL  BSCL53_BL  timepoint
  0          IA1    1_1        1  ...          2          4          1
  1          AI7    1_2        1  ...          3          2          1
  2         RE11    1_3        1  ...          1          2          1
  3     EA11/EA4    1_4        1  ...          1          2          1
  4          UA2    1_5        1  ...        -33        -33          1 
  </code></pre>
  <p>and i want to have something like this .... so with the <code>ID</code></p>
  <pre><code>ID    VPN Code    pid  VTS/VTA  ...  BSCL52_BL  BSCL53_BL  timepoint
  0          IA1    1_1        1  ...          2          4          1
  1          AI7    1_2        1  ...          3          2          1
  2         RE11    1_3        1  ...          1          2          1
  3     EA11/EA4    1_4        1  ...          1          2          1
  4          UA2    1_5        1  ...        -33        -33          1 
  </code></pre>
  <p>anyone who could help me and tell me whats wrong ?</p>
  <p>Thank you very much!</p>