title: "In" operator for numpy arrays?
body: <p>How can I do the "in" operation on a numpy array?
  (Return True if an element is present in the given numpy array)</p>
  
  <p>For strings, lists and dictionaries, the functionality is intuitive to understand.</p>
  
  <p>Here's what I got when I applied that on a numpy array</p>
  
  <pre><code>a
  array([[[2, 3, 0],
      [1, 0, 1]],
  
     [[3, 2, 0],
      [0, 1, 1]],
  
     [[2, 2, 0],
      [1, 1, 1]],
  
     [[1, 3, 0],
      [2, 0, 1]],
  
     [[3, 1, 0],
      [0, 2, 1]]])
  
  b = [[3, 2, 0],
      [0, 1, 1]]
  
  b in a
  True
  #Aligned with the expectation
  
  c = [[300, 200, 0],
      [0, 100, 100]]
  
  c in a
  True
  #Not quite what I expected
  </code></pre>