title: Plsease expain following python codes
body: <p>Why x value is updating along with y, how it works any one please expain this code</p>
  
  <pre><code>x = ['foo', [1,2,3], 10.4]
  y = list(x)
  y[0] = 'fooooooo'
  y[1][0] = 4
  print x
  print y
  
  Output 
  ['foo', [4, 2, 3], 10.4]
  ['fooooooo', [4, 2, 3], 10.4]
  </code></pre>