title: Error in reading html to data frame in Python "'module' object has no attribute '_base'"
body: <p>I encounter this error when trying to read a table from url (link <a href="http://www.checkee.info/main.php?dispdate=" rel="nofollow">here</a>). </p>
  
  <p>Here is the code:</p>
  
  <pre><code>import pandas as pd
  link = "http://www.checkee.info/main.php?dispdate="
  c=pd.read_html(link)
  </code></pre>
  
  <p>The error returned is: AttributeError: 'module' object has no attribute '_base'</p>
  
  <p>Specifically</p>
  
  <pre><code>---------------------------------------------------------------------------
  AttributeError                            Traceback (most recent call last)
  &lt;ipython-input-2-5e6036f08795&gt; in &lt;module&gt;()
        1 link = "http://www.checkee.info/main.php?dispdate="
  ----&gt; 2 c=pd.read_html(link)
  
  /Users/lanyiyun/anaconda/lib/python2.7/site-packages/pandas/io/html.pyc in read_html(io, match, flavor, header, index_col, skiprows, attrs, parse_dates, tupleize_cols, thousands, encoding)
      859     pandas.read_csv
      860     """
  --&gt; 861     _importers()
      862 
      863     # Type check here. We don't want to parse only to fail because of an
  
  /Users/lanyiyun/anaconda/lib/python2.7/site-packages/pandas/io/html.pyc in _importers()
       40 
       41     try:
  ---&gt; 42         import bs4  # noqa
       43         _HAS_BS4 = True
       44     except ImportError:
  
  /Users/lanyiyun/anaconda/lib/python2.7/site-packages/bs4/__init__.py in &lt;module&gt;()
       28 import warnings
       29 
  ---&gt; 30 from .builder import builder_registry, ParserRejectedMarkup
       31 from .dammit import UnicodeDammit
       32 from .element import (
  
  /Users/lanyiyun/anaconda/lib/python2.7/site-packages/bs4/builder/__init__.py in &lt;module&gt;()
      312 register_treebuilders_from(_htmlparser)
      313 try:
  --&gt; 314     from . import _html5lib
      315     register_treebuilders_from(_html5lib)
      316 except ImportError:
  
  /Users/lanyiyun/anaconda/lib/python2.7/site-packages/bs4/builder/_html5lib.py in &lt;module&gt;()
       68 
       69 
  ---&gt; 70 class TreeBuilderForHtml5lib(html5lib.treebuilders._base.TreeBuilder):
       71 
       72     def __init__(self, soup, namespaceHTMLElements):
  
  AttributeError: 'module' object has no attribute '_base'
  </code></pre>
  
  <p>Anyone knows what the problem causes this? Thanks!</p>