title: How to set a list as the index of an existing pandas dataframe?
body: <p>I have an existing pandas dataframe, which looks something like:</p>
  
  <pre><code>    Gr          R           B           Gb
  0   1.537037    1.733333    1.400000    1.537037
  1   1.657952    1.706522    1.650407    1.713024
  2   1.670982    1.690476    1.626263    1.661202
  3   1.689229    1.683761    1.607143    1.676923
  ...
  </code></pre>
  
  <p>I have a separate list, where the length of the list is equal to the number of rows in the above dataframe. Something like:</p>
  
  <p><code>separate_list = ['a','b','c',....]</code></p>
  
  <p>How can I make the separate list to be the index of the above dataframe, replacing the default index (0,1,2,...)? All I can find are ways to set an <strong>existing column</strong> to the index.</p>
  
  <p>Thank you.</p>