title: Remove dtype at the end of numpy array
body: <p>I'm writing a method to create an array from data file. The method looks like:</p>
  
  <pre><code>import numpy
  def readDataFile(fileName):
      try:
          with open(fileName, 'r') as inputs:
              data = None
              for line in inputs:
                  line = line.strip()
                  items = line.split('\t')
                  if data == None:
                      data = numpy.array(items[0:len(items)]) 
                  else:
                      data = numpy.vstack((data, items[0:len(items)]))
                  return numpy.array(data)
      except IOError as ioerr:
          print 'IOError: ', ioerr
          return None
  </code></pre>
  
  <p>My data file contains lines of numbers, each of which is separated from each other by a tab, e.g:</p>
  
  <pre><code>1 2 3
  4 5 6
  7 8 9
  </code></pre>
  
  <p>And I expect to receive an array as follows:</p>
  
  <pre><code>array([[1, 2, 3],
         [4, 5, 6],
         [7, 8, 9]])
  </code></pre>
  
  <p>However, the result contains <code>dtype</code> at the end of it:</p>
  
  <pre><code>array([[1, 2, 3],
         [4, 5, 6],
         [7, 8, 9]], dtype='|S9')
  </code></pre>
  
  <p>Because of it, I cannot perform some operations on the result, e.g. if I try to find the max value for each line using <code>result.max(0)</code>, I'll receive an error: </p>
  
  <blockquote>
    <p>TypeError: cannot perform reduce with flexible type.</p>
  </blockquote>
  
  <p>So, can anyone tell me what's wrong with my code and how to fix it? Thanks a lot.</p>