title: why there are more strings in python np array output?
body: <p>I'm confused as to why the following code answer is:</p>
  <pre><code>import numpy as np
  dt=[('name','S16'),('grad',int),('cpg',float)]
  val=[(&quot;Ahmadmm&quot;,2008,12),('ali',2010,12.2),('mitra',505,15.15)]
  arr=np.array(val,dtype=dt)
  print(arr)
  
  output:  [(b'Ahmadmm', 2008, 12.  ) (b'ali', 2010, 12.2 ) (b'mitra',  505, 15.15)]
  </code></pre>
  <p>Why there is a 'b' before each string?</p>