title: Is there a builtin identity function in python?
body: <p>I'd like to point to a function that does nothing:</p>
  
  <pre><code>def identity(*args)
      return args
  </code></pre>
  
  <p>my use case is something like this</p>
  
  <pre><code>try:
      gettext.find(...)
      ...
      _ = gettext.gettext
  else:
      _ = identity
  </code></pre>
  
  <p>Of course, I could use the <code>identity</code> defined above, but a built-in would certainly run faster (and avoid bugs introduced by my own).</p>
  
  <p>Apparently, <code>map</code> and <code>filter</code> use <code>None</code> for the identity, but this is specific to their implementations.</p>
  
  <pre><code>&gt;&gt;&gt; _=None
  &gt;&gt;&gt; _("hello")
  Traceback (most recent call last):
    File "&lt;stdin&gt;", line 1, in &lt;module&gt;
  TypeError: 'NoneType' object is not callable
  </code></pre>