title: Python arrays are automatically copying each other
body: <p>I am a beginner at python and I don't want these arrays to copy each other but they are automatically:</p>
  
  <pre><code>a = numpy.zeros(4)
  b = a
  a[1] = 10
  print b[1]
  </code></pre>
  
  <p>and it returns 10 instead of 0.  How do I disconnect these two arrays?</p>