title: Calling goodness of fit value with result.prsquared() in statsmodels results TypeError: 'numpy.float64' object is not callable
body: <p>I am a complete beginner, and I'm currently doing this tutorial about logit regression models in python 3.4, with statsmodels 0.6.1 and Pycharm community version 4.5.1:</p>
  
  <p><a href="http://blog.yhathq.com/posts/logistic-regression-and-python.html" rel="nofollow">http://blog.yhathq.com/posts/logistic-regression-and-python.html</a></p>
  
  <p>It runs smoothly. I try to add my own lines, to try out a few things.</p>
  
  <p>After the part when I fit the data</p>
  
  <pre><code>train_cols = data.columns[1:]
  logit = sm.logit(data['admit'], data[train_cols])
  result = logit.fit()
  </code></pre>
  
  <p>and I print out the summary</p>
  
  <pre><code>print(result.summary())
  </code></pre>
  
  <p>I tried to take a little detour from the tutorial, to print only the Goodness of Fit measurement (in this case, it is a pseudo R-squared value). According to the <a href="http://statsmodels.sourceforge.net/devel/generated/statsmodels.discrete.discrete_model.LogitResults.html#statsmodels.discrete.discrete_model.LogitResults" rel="nofollow">documentation</a> it is a method of result object (same as summary), so it should work like this:</p>
  
  <pre><code>print(result.prsquared())
  </code></pre>
  
  <p>However, running this code results in a TypeError on a line containing only print(result.prsquared()):</p>
  
  <blockquote>
    <p>TypeError: 'numpy.float64' object is not callable</p>
  </blockquote>
  
  <p>It really bugs me, because if I would to compare several models, pseudo R-squared would be my first choice to do it.</p>