title: Strange unknown lambda syntax
body: <p>I know what this does (makes <code>k</code> refer to then actual value instead of last value) but what is this syntax called?
  Comes from <a href="https://stackoverflow.com/a/215326/2375119">https://stackoverflow.com/a/215326/2375119</a> </p>
  
  <pre><code>funcs = [] 
  for k in range(10):
       funcs.append(lambda k = k: k)
  
  &gt;&gt;&gt; funcs[7]()
  7 # not 9
  </code></pre>