Is it safe to use os.environ.setdefault?
<p>From my ipython shell, I see a method setdefault in os.environ but it is not documented. <a href="http://docs.python.org/library/os.html#os.environ" rel="nofollow">http://docs.python.org/library/os.html#os.environ</a>. Is it documented somewhere else?</p>

<pre><code>def setdefault(self, key, failobj=None):
    if key not in self:
        self[key] = failobj
    return self[key]
</code></pre>

<p>Can I use this function or write a wrapper for those lines?</p>
