title: Remove the first or last char so the values from a column should start with numbers
body: <p>I'm new to Pandas and I'd like to ask your advice.
  Let's take this dataframe:</p>
  <pre><code>df_test = pd.DataFrame({'Dimensions': ['22.67x23.5', '22x24.6', '45x56', 'x23x56.22','46x23x','34x45'],
                       'Other': [59, 29, 73, 56,48,22]})
  </code></pre>
  <p>I want to detect the lines that starts with &quot;x&quot; (line 4) or ends with &quot;x&quot; (line 5) and then remove them so my dataframe should look like this</p>
  <pre><code>Dimensions  Other
  22.67x23.5  59
  22x24.6     29
  45x56       73
  23x56.22    56
  46x23       48
  34x45       22
  </code></pre>
  <p>I wanted to create a function and apply it to a column</p>
  <pre><code>def remove_x(x):
      if (x.str.match('^[a-zA-Z]') == True):
          x = x[1:]
          return x
      if (x.str.match('.*[a-zA-Z]$') == True):
          x = x[:-1]
          return x
  </code></pre>
  <p>If I apply this function to the column</p>
  <pre><code>df_test['Dimensions'] = df_test['Dimensions'].apply(remove_x)
  </code></pre>
  <p>I got an error 'str' object has no attribute 'str'
  I delete 'str' from the function and re-run all but no success.</p>
  <p>What should I do?
  Thank you for any suggestions or if there is another way to do it I'm interested in.</p>