title: Why does Pylint object to single-character variable names?
body: <p>I'm still getting used to Python conventions and using Pylint to make my code more Pythonic, but I'm puzzled by the fact that Pylint doesn't like single character variable names. I have a few loops like this:</p>
  <pre><code>for x in x_values:
     my_list.append(x)
  </code></pre>
  <p>and when I run <code>pylint</code>, I'm getting <code>Invalid name &quot;x&quot; for type variable (should match [a-z_][a-z0-9_]{2,30}</code> -- that suggests that a valid variable name must be between 3 and 31 characters long, but I've looked through the <a href="http://www.python.org/dev/peps/pep-0008/#naming-conventions" rel="noreferrer">PEP8 naming conventions</a> and I don't see anything explicit regarding single lower case letters, and I do see a lot of examples that use them.</p>
  <p>Is there something I'm missing in PEP8 or is this a standard that is unique to Pylint?</p>