title: statsmodels.formula.api importError: cannot import name 'TimeSeries'
body: <p>New to python here.</p>
  
  <p>Using the following:
  Anaconda - v1.3.1
  Spyder - v3.1.4
  Python - v3.5</p>
  
  <p>I am trying to import the following libraries:</p>
  
  <pre><code>import numpy as np
  import matplotlib.pyplot as plt
  import pandas as pd
  import statsmodels.formula.api as sm
  </code></pre>
  
  <p>It keeps giving me the following error:</p>
  
  <pre><code>import statsmodels.formula.api as sm
  Traceback (most recent call last):
  
    File "&lt;ipython-input-2-2515cefb61aa&gt;", line 1, in &lt;module&gt;
      import statsmodels.formula.api as sm
  
    File "//anaconda/lib/python3.5/site-packages/statsmodels/formula/api.py", line 1, in &lt;module&gt;
      from statsmodels.regression.linear_model import GLS
  
    File "//anaconda/lib/python3.5/site-packages/statsmodels/regression/__init__.py", line 1, in &lt;module&gt;
      from .linear_model import yule_walker
  
    File "//anaconda/lib/python3.5/site-packages/statsmodels/regression/linear_model.py", line 52, in &lt;module&gt;
      import statsmodels.base.model as base
  
    File "//anaconda/lib/python3.5/site-packages/statsmodels/base/model.py", line 5, in &lt;module&gt;
      from statsmodels.base.data import handle_data
  
    File "//anaconda/lib/python3.5/site-packages/statsmodels/base/data.py", line 8, in &lt;module&gt;
      from pandas import DataFrame, Series, TimeSeries, isnull
  
  ImportError: cannot import name 'TimeSeries'
  </code></pre>
  
  <p>I read some posts about updating pandas. I tried that but it doesn't work. Any ideas as to the error and a solution? (It works fine when I import only statsmodel.formula or just statsmodel)</p>