title: AssertionError: 22 columns passed, passed data had 21 columns
body: <p>This is my code:</p>
  
  <pre><code>from urllib import urlopen
  from bs4 import BeautifulSoup
  import pandas as pd
  
  url = "http://www.basketball-reference.com/draft/NBA_2014.html"
  html = urlopen(url)
  soup = BeautifulSoup(html)
  column_headers = [th.getText() for th in soup.findAll('tr',limit=2)[1].findAll('th')]
  data_rows = soup.findAll('tr')[2:]
  player_data = [[td.getText() for td in data_rows[i].findAll('td')] for i in range(len(data_rows))] #PLAYER DATA 
  
  type(soup)
  type(data_rows)
  
  df = pd.DataFrame(player_data,columns=column_headers)
  </code></pre>
  
  <p>The error seems to occur in the last line.</p>