title: numpy: Replacing values in a recarray
body: <p>I'm pretty new to numpy, and I'm trying to replace a value in a recarray. So I have this array:</p>
  
  <pre><code>import numpy as np
  d = [('1', ''),('4', '5'),('7', '8')]
  a = np.array(d, dtype=[('first', 'a5'), ('second', 'a5')])
  </code></pre>
  
  <p>I would like to do something like this:</p>
  
  <pre><code>ind = a=='' #Replace all blanks
  a[ind] = '12345'
  </code></pre>
  
  <p>but that doesnt work properly. I was able to do this:</p>
  
  <pre><code>col = a['second']
  ind = col=='' #Replace all blanks
  col[ind] = '54321'
  a['second'] = col
  </code></pre>
  
  <p>Which works, but I would rather have a way to do it over the entire recarray. Anyone have a better solution?</p>