title: Frequency counts for unique values in a NumPy array
body: <p>How do I efficiently obtain the frequency count for each unique value in a NumPy array?</p>
  <pre><code>&gt;&gt;&gt; x = np.array([1,1,1,2,2,2,5,25,1,1])
  &gt;&gt;&gt; freq_count(x)
  [(1, 5), (2, 3), (5, 1), (25, 1)]
  </code></pre>