title: Python: Why is functools.partial necessary?
body: <p>Partial application is cool. What functionality does <a href="https://docs.python.org/3/library/functools.html#functools.partial" rel="noreferrer"><code>functools.partial</code></a> offer that you can't get through lambdas?</p>
  
  <pre><code>&gt;&gt;&gt; sum = lambda x, y : x + y
  &gt;&gt;&gt; sum(1, 2)
  3
  &gt;&gt;&gt; incr = lambda y : sum(1, y)
  &gt;&gt;&gt; incr(2)
  3
  &gt;&gt;&gt; def sum2(x, y):
      return x + y
  
  &gt;&gt;&gt; incr2 = functools.partial(sum2, 1)
  &gt;&gt;&gt; incr2(4)
  5
  </code></pre>
  
  <p>Is <code>functools</code> somehow more efficient, or readable?</p>