title: Check if a value exists in an array in Cython
body: <p>I want to know how to check if a value or a object exists in an array, like in python:</p>
  
  <pre><code>a = [1,2,3,4,5]
  b = 4
  if b in a:
      print("True!")
  else:
      print("False")
  </code></pre>
  
  <p>I want to know if something similar already exists in cython. I have a struct object array of pointers; I want to know if the object exists in this array. </p>
  
  <p>Like</p>
  
  <pre><code>cdef Node *array
  
  array = &lt;Node *&gt;malloc( 5 * cython.sizeof(Node))
  
  for i in range(5):
       array[i].index = i
  
  cdef Node test = array[3]
  
  if test in array:
      print("True!")
  
  cdef struct Node:
      int index
  </code></pre>
  
  <p>The code above is not correct, but it illustrates what I mean.</p>