Error in hw1_solutions part 3:Analysis

[abhijeetchauhan]

AttributeError                            Traceback (most recent call last)
<ipython-input-30-aea6d425eefd> in <module>()
----> 1 errors = all_error_data()

<ipython-input-29-2a9c686164e8> in all_error_data()
     17 #your code here
     18 def all_error_data():
---> 19     data = [error_data(race_page) for race_page in find_governor_races(page)]
     20     return pd.concat(data, ignore_index=True)

<ipython-input-28-5c576ec1e316> in error_data(url)
     48     #compute forecast length in days
     49     #(assuming that last forecast happens on the day of the election, for simplicity)
---> 50     forecast_length = (df.date.max() - df.date).values
     51     forecast_length = forecast_length / np.timedelta64(1, 'D')  # convert to number of days
     52 

/home/abhijeet/anaconda3/envs/py27/lib/python2.7/site-packages/pandas/core/generic.pyc in __getattr__(self, name)
   2667             if name in self._info_axis:
   2668                 return self[name]
-> 2669             return object.__getattribute__(self, name)
   2670 
   2671     def __setattr__(self, name, value):

AttributeError: 'DataFrame' object has no attribute 'date'