title: What are "soft keywords"?
body: <p>According to the documentation of the <a href="https://docs.python.org/3/library/keyword.html" rel="noreferrer"><code>keyword</code> module</a>, two new members have been added in Python 3.9:</p>
  <ul>
  <li><code>issoftkeyword</code></li>
  <li><code>softkwlist</code></li>
  </ul>
  <p>However their documentation doesn't reveal anything about their purpose. This change is not even mentioned in the <a href="https://docs.python.org/3/whatsnew/3.9.html" rel="noreferrer">What's New</a> article, where typically all API changes are documented. Digging a little further into the <a href="https://github.com/python/cpython/blob/3.9/Lib/keyword.py" rel="noreferrer">source code</a> eventually leads to this <a href="https://github.com/python/cpython/pull/20877" rel="noreferrer">pull request</a> where it is mentioned that <em>&quot;this is essentially an internal tool&quot;</em> and that <em>&quot;soft keywords are still unused&quot;</em>. So what's the purpose of Python's soft keywords?</p>