title: TypeError: can't multiply sequence by non-int of type 'float' (python 2.7)
body: <p>I have a dataframe <code>t_unit</code>, which is the result of a <code>pd.read_csv()</code> function.</p>
  
  <pre><code>datetime    B18_LR_T    B18_B1_T
  24/03/2016 09:00    21.274  21.179
  24/03/2016 10:00    19.987  19.868
  24/03/2016 11:00    21.632  21.417
  24/03/2016 12:00    26.285  24.779
  24/03/2016 13:00    26.897  24.779
  </code></pre>
  
  <p>I am resampling the dataframe to calculate the 5th and 05th percentiles with the code:</p>
  
  <pre><code>keys_actual = list(t_unit.columns.values)
  
  for key in keys_actual:
      ts_wk = t_unit[key].resample('W-MON')
      ts_wk_05p = ts_wk.apply(lambda x: x.quantile(0.05)).round(decimals=1).rename(key+'_05p', inplace=True)
      ts_wk_95p = ts_wk.apply(lambda x: x.quantile(0.95)).round(decimals=1).rename(key+'_95p', inplace=True) 
  </code></pre>
  
  <p>All works fine, but when I add a column to my dataframe, by means of <code>pd.concat</code>, into:</p>
  
  <pre><code>datetime    B18_LR_T    B18_B1_T    ext_T
  24/03/2016 09:00    21.274  21.179  6.9
  24/03/2016 10:00    19.987  19.868  7.5
  24/03/2016 11:00    21.632  21.417  9.1
  24/03/2016 12:00    26.285  24.779  9.9
  24/03/2016 13:00    26.897  24.779  9.2
  </code></pre>
  
  <blockquote>
    <p>ts_wk_05p = ts_wk.apply(lambda x: x.quantile(0.05)).round(decimals=1).rename(key+'_05p', inplace=True)</p>
    
    <p>TypeError: can't multiply sequence by non-int of type 'float'</p>
  </blockquote>
  
  <p>Do you have any idea why?</p>