title: TypeError: mean() got an unexpected keyword argument 'dtype' # Pandas.DataFrame
body: <p>I want to get the <code>numpy.mean</code> of each column of my <code>pandas.DataFrame</code>.</p>
  
  <p>Here is my code:</p>
  
  <pre><code>import pandas as pd
  import numpy as np
  
  prices = pd.DataFrame([[-0.33333333, -0.25343423, -0.1666666667],
                         [+0.23432323, +0.14285714, -0.0769230769],
                         [+0.42857143, +0.07692308, +0.1818181818]])
  
  print(np.mean(prices, axis=0))
  </code></pre>
  
  <p>If I run this code, I'll get the following error:</p>
  
  <pre><code>Traceback (most recent call last):
    File "C:\Users\*****\Documents\Python\******\****.py", line 8, in &lt;module&gt;
      print(np.mean(new, axis=0))
    File "C:\Python33\lib\site-packages\numpy\core\fromnumeric.py", line 2711, in mean
      return mean(axis=axis, dtype=dtype, out=out)
  TypeError: mean() got an unexpected keyword argument 'dtype'
  </code></pre>
  
  <p>How can I fix that?</p>
  
  <p><strong>NOTE:</strong> here is an expected output: <code>pd.DataFrame([0.1098537767, -0.0112180033, -0.0205905206])</code></p>