title: Python: can numba work with arrays of strings in nopython mode?
body: <p>I am using pandas 0.16.2, numpy 1.9.2 and numba 0.20.</p>
  
  <p>Is there any way to get numba to support arrays of strings in nopython mode?
  Alternatively, could I somehow convert strings to numbers which numba would recognise?</p>
  
  <p>I have to run certain loops on an array of strings (a column from a pandas dataframe); if I could use numba the code would be substantially faster.</p>
  
  <p>I have come up with this minimal example to show what I mean:</p>
  
  <pre><code>import numpy as np
  import numba
  
  x=np.array(['some','text','this','is'])
  
  @numba.jit(nopython=True)
  def numba_str(txt):
      x=0
      for i in xrange(txt.size):
          if txt[i]=='text':
              x += 1
      return x
  
  print numba_str(x)
  </code></pre>
  
  <p>The error I get is:</p>
  
  <pre><code>Failed at nopython (nopython frontend)
  Undeclared ==([char x 4], str)
  </code></pre>
  
  <p>Thanks!</p>