title: How to convert from a dtype('o') to a dtype(float) in numpy?
body: <p>I'm looking for a way to read this csv into python 2.7 and turn it into a (3,22000) array.  For some reason I haven't been able to do it, no matter which way i try, I either get a groupn of strings in an array that i cant convert or an array seen below that won't convert to floats or allow computations to be done on them.  Any help would be appreciated.  Thanks</p>
  
  <p>For the record it says the shape is (22000,), which I'm unsure about also.</p>
  
  <pre><code>In [126]: import csv
  import numpy as np
  
  with open("Data.csv") as sd:
  ri = []
  dv = []
  for row in csv.reader(sd):
      if row != ["ccx","ccy","ccz","cellVolumes","Cell Type"]:
          nrow = []
          for val in row[0:3]:
              val = float(val)
              nrow.append(val)
          ri.append(nrow)
  
          nrow = []
          for val in row[3:4]:
              val = float(val)
              nrow.append(val)
          dv.append(nrow)
  
  ri = np.array(ri)
  ri
  </code></pre>
  
  <p>.</p>
  
  <pre><code>Out[126]: array([[-0.179967, -0.38936, -0.46127], [-0.0633236, -0.407683, -0.542979],
     [-0.125841, -0.494202, -0.412042], ...,
     [-0.0116821, 0.764493, 0.573541], [0.630377, 0.469657, 0.442017],
     [0.248253, 0.615365, 0.354134]], dtype=object
  </code></pre>