title: Read csv files that contain/without certain character
body: <p>I have several csv files in a same folder, some contain the character '^' and some don't, I read them as df in the way below:</p>
  <pre><code>def readfile(f):
      df = pd.read_csv(f)
      df['ticker'] = f.split('.')[0].strip('^')
      return df
  </code></pre>
  <p>And now I want to define two functions likewise, but:</p>
  <ol>
  <li><code>readfile1(f)</code> such that it only reads files that <strong>doesn't contain ^</strong>, and return the df with the ticker as the file name.</li>
  <li><code>readfile2(f)</code> such that it only reads files that <strong>contain ^</strong>, and return the df with the ticker as the file name without the ^</li>
  </ol>
  <p>Can I do that by making some changes on <code>readfile</code>?</p>