title: Finding whether a list contains a particular numpy array
body: <pre><code>import numpy as np
  
  a = np.eye(2)
  b = np.array([1,1],[0,1])
  
  my_list = [a, b]
  </code></pre>
  
  <p><code>a in my_list</code> returns <code>true</code>, but <code>b in my_list</code> returns "ValueError: The truth value of an array with more than one element is ambiguous. Use a.any() or a.all()". I can get around this by converting the arrays to strings or lists first, but is there a nicer (more Pythonic) way of doing it?</p>