title: Numpy : load csv file and read string value using genfromtxt gives warning
body: <p>I know Warnings are not important, the question might be duplicate but I didn't find a proper solution yet.
  I am using the below code for reading the .csv file from the URL. </p>
  
  <pre><code>path = 'https://raw.githubusercontent.com/selva86/datasets/master/Auto.csv'
  data=np.genfromtxt(path,delimiter=',',skip_header=1,dtype=None)
  new_arr=data[:3]
  print(new_arr)
  </code></pre>
  
  <p>I want to read numbers and String from the file, I am getting the output </p>
  
  <pre><code>[(18., 8, 307., 130, 3504, 12. , 70, 1, b'"chevrolet chevelle malibu"')
   (15., 8, 350., 165, 3693, 11.5, 70, 1, b'"buick skylark 320"')
   (18., 8, 318., 150, 3436, 11. , 70, 1, b'"plymouth satellite"')]
  </code></pre>
  
  <p>But here when I specify dtype=None with output I am also getting the below warning. What is the reason behind this warning?</p>
  
  <blockquote>
    <p>......./Tutorial/PythonProjects/MyTutorials/venv/lib/python3.6/site-packages/ipykernel_launcher.py:2:
    VisibleDeprecationWarning: Reading unicode strings without specifying
    the encoding argument is deprecated. Set the encoding, use None for
    the system default.</p>
  </blockquote>
  
  <p>As I am new to python and numpy post your comments below.</p>