title: pep8 compliance testing is failing
body: <p>I've followed Head First Python 2nd Edition and a pep8 compliance testing is demonstrated in chapter 4.</p>
  <p>When running  <strong>py.test --pep8 searchV.py</strong>  gives error</p>
  <p>appdata\local\programs\python\python38\lib\site-packages\pep8.py:110: FutureWarning: Possible nested set at position 1
  EXTRANEOUS_WHITESPACE_REGEX = re.compile(r'[[({] | []}),;:]')
  ===============test session starts =========================================
  platform win32 -- Python 3.8.6, pytest-6.2.1, py-1.10.0, pluggy-0.13.1
  rootdir: D:\work\py-modules
  plugins: pep8-1.0.6
  <em><strong>collected 0 items / 1 error</strong></em></p>
  <p>=============== ERRORS =======================================================
  _______________ERROR collecting test session ____
  Direct construction of Pep8Item has been deprecated, please use Pep8Item.from_parent.
  See <a href="https://docs.pytest.org/en/stable/deprecations.html#node-construction-changed-to-node-from-parent" rel="nofollow noreferrer">https://docs.pytest.org/en/stable/deprecations.html#node-construction-changed-to-node-from-parent</a> for more details.
  ==========short test summary info ===============
  ERROR
  !!!!!!!!!!!!!!!!!!!!Interrupted: 1 error during collection !!!!!!!!!!!!!!!!!!!!!!</p>
  <p>Here's the code in serachV.py</p>
  <pre><code>def search_letter(phrase: str , letter:str='aeiou')-&gt;set:
      &quot;&quot;&quot; Serach for letter in phrase&quot;&quot;&quot;
      return set(letter).intersection(set(phrase))
  </code></pre>
  <p>Not sure why no items are collected ?</p>