title: How to read index data as string with pandas.read_csv()?
body: <p>I'm trying to read csv file as DataFrame with pandas, and I want to read index row as string. However, since the row for index doesn't have any characters, pandas handles this data as integer. How to read as string?</p>
  
  <p>Here are my csv file and code:</p>
  
  <pre><code>[sample.csv]    
      uid,f1,f2,f3
      01,0.1,1,10
      02,0.2,2,20
      03,0.3,3,30
  
  [code]
  df = pd.read_csv('sample.csv', index_col="uid" dtype=float)
  print df.index.values
  </code></pre>
  
  <p>The result: df.index is integer, not string:</p>
  
  <pre><code>&gt;&gt;&gt; [1 2 3]
  </code></pre>
  
  <p>But I want to get df.index as string:</p>
  
  <pre><code>&gt;&gt;&gt; ['01', '02', '03']
  </code></pre>
  
  <p>And an additional condition: The rest of index data have to be numeric value and they're actually too many and I can't point them with specific column names.</p>