title: Python - "cannot perform reduce with flexible type" when trying to use numpy.mean
body: <p>I'm at my wit's end as I keep getting "cannot perform reduce with flexible type" when I try to compute the mean of a column, the file is read in just fine (no missing values in any rows/column) but when I put in the line: 
  Brain_wt_mean = np.mean(ifile axis=0) then Python 2.7.5 does not like it. I am using this within the Spyder IDE. Thanks much for any help.</p>
  
  <pre><code>import os
  import numpy as np
  
  if __name__ == "__main__":
      try:        
          curr_dir = os.getcwd()
          file_path = curr_dir + '\\brainandbody.csv'
          ifile = np.loadtxt('brainandbody.csv', delimiter=',', skiprows=1, dtype=[('brainwt', 'f8'), ('bodywt', 'f8')])
  
      except IOError:
          print "The file does not exist, exiting gracefully"        
  
  Brain_wt_mean = np.mean(ifile axis=0)
  
  
  
  
  ### BELOW is a sample of the csv file ######
  
  Brain Weight    Body Weight
  3.385   44.5
  0.48    15.5
  1.35    8.1
  465 423
  36.33   119.5
  27.66   115
  14.83   98.2
  1.04    5.5
  </code></pre>