title: Remove url strings from series
body: <p>I have a function to remove url links from a series, but it doesn't appear to work. The error when I pass the series through the function is: 'str' object has no attribute 're'</p>
  
  <pre><code>def remove_url(list_of_tokens):
      '''
      Remove url
      ''' 
  
      cleaned_tokens = [] 
  
      for token in list_of_tokens: 
          token = token.re.sub(r"http\S+", "")
          cleaned_tokens.append(token)
  
      return cleaned_tokens
  </code></pre>