title: How to run sqlacodegen?
body: <p>I'm trying to run sqlacodegen to create a SQLAlchemy model from an existing PostgreSQL database.</p>
  <p>It won't run.  When I type <code>sqlacodegen --help</code> I get:</p>
  <pre><code>Traceback (most recent call last):
    File &quot;&lt;stdin&gt;&quot;, line 1, in &lt;module&gt;
  TypeError: bad operand type for unary -: '_Helper'
  </code></pre>
  <p>Basic instructions are <a href="https://pypi.python.org/pypi/sqlacodegen" rel="nofollow noreferrer">here</a>.</p>
  <p>How do you get sqlacodegen to run?</p>