title: get python pandas to_dict with orient='records' but without float cast
body: <p>I have a dataframe with one col int one col floats:</p>
  
  <pre><code>df
  #    a      b
  # 0  3  42.00
  # 1  2   3.14
  
  df.dtypes
  # a      int64
  # b    float64
  # dtype: object
  </code></pre>
  
  <p>I want a list of dicts like the one provide by <code>df.to_dict(orient='records')</code></p>
  
  <pre><code>df.to_dict(orient='records')
  [{'a': 3.0, 'b': 42.0}, {'a': 2.0, 'b': 3.1400000000000001}]
  </code></pre>
  
  <p>But with <code>a</code> as <code>int</code>, not casted as float</p>