In [1]:

    

import pandas as pd
import numpy as np
import matplotlib.pyplot as plt

%matplotlib inline


    

In [9]:

    

df = pd.read_csv('articles-by-dates.csv',parse_dates=True)


    

In [10]:

    

df.head()


    

    
Out[10]:






  

    

      

      
extremely-rare-giant-panda-cub-born-in-true-miracle
      
2016-06-03
    
  
  

    

      
0
      
9-surprising-places-that-inspired-famous-books...
      
2016-06-03
    
    

      
1
      
watch-a-museum-visitor-touch-and-destroy-a-pri...
      
2016-06-03
    
    

      
2
      
american-idol-coyote-edition
      
2016-06-03
    
    

      
3
      
the-first-woman-to-drive-around-the-world-wore...
      
2016-06-03
    
    

      
4
      
fireflies-that-blink-in-sync-return-to-tennessee
      
2016-06-03
    
  

In [17]:

    

pd.to_datetime(df)


    

    




---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
<ipython-input-17-7cad31999ec7> in <module>()
----> 1 pd.to_datetime(df)

/Users/Mike/anaconda/lib/python2.7/site-packages/pandas/util/decorators.pyc in wrapper(*args, **kwargs)
     89                 else:
     90                     kwargs[new_arg_name] = new_arg_value
---> 91             return func(*args, **kwargs)
     92         return wrapper
     93     return _deprecate_kwarg

/Users/Mike/anaconda/lib/python2.7/site-packages/pandas/tseries/tools.pyc in to_datetime(arg, errors, dayfirst, yearfirst, utc, box, format, exact, coerce, unit, infer_datetime_format)
    289                         yearfirst=yearfirst,
    290                         utc=utc, box=box, format=format, exact=exact,
--> 291                         unit=unit, infer_datetime_format=infer_datetime_format)
    292 
    293 

/Users/Mike/anaconda/lib/python2.7/site-packages/pandas/tseries/tools.pyc in _to_datetime(arg, errors, dayfirst, yearfirst, utc, box, format, exact, unit, freq, infer_datetime_format)
    421         return Series(values, index=arg.index, name=arg.name)
    422     elif isinstance(arg, (ABCDataFrame, MutableMapping)):
--> 423         return _assemble_from_unit_mappings(arg, errors=errors)
    424     elif isinstance(arg, ABCIndexClass):
    425         return _convert_listlike(arg, box, format, name=arg.name)

/Users/Mike/anaconda/lib/python2.7/site-packages/pandas/tseries/tools.pyc in _assemble_from_unit_mappings(arg, errors)
    497         raise ValueError("to assemble mappings requires at "
    498                          "least that [year, month, day] be specified: "
--> 499                          "[{0}] is missing".format(','.join(req)))
    500 
    501     # keys we don't recognize

ValueError: to assemble mappings requires at least that [year, month, day] be specified: [day,month,year] is missing

In [11]:

    

df.set_index('2016-06-03',inplace=True)


    

In [12]:

    

df.head()


    

    
Out[12]:






  

    

      

      
extremely-rare-giant-panda-cub-born-in-true-miracle
    
    

      
2016-06-03
      

    
  
  

    

      
2016-06-03
      
9-surprising-places-that-inspired-famous-books...
    
    

      
2016-06-03
      
watch-a-museum-visitor-touch-and-destroy-a-pri...
    
    

      
2016-06-03
      
american-idol-coyote-edition
    
    

      
2016-06-03
      
the-first-woman-to-drive-around-the-world-wore...
    
    

      
2016-06-03
      
fireflies-that-blink-in-sync-return-to-tennessee
    
  

In [13]:

    

df['count'] = 1


    

In [14]:

    

df.head(1)


    

    
Out[14]:






  

    

      

      
extremely-rare-giant-panda-cub-born-in-true-miracle
      
count
    
    

      
2016-06-03
      

      

    
  
  

    

      
2016-06-03
      
9-surprising-places-that-inspired-famous-books...
      
1
    
  

In [15]:

    

df_resampled = df.resample('M',how='sum')


    

    




---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-15-aabf4dbc99b6> in <module>()
----> 1 df_resampled = df.resample('M',how='sum')

/Users/Mike/anaconda/lib/python2.7/site-packages/pandas/core/generic.pyc in resample(self, rule, how, axis, fill_method, closed, label, convention, kind, loffset, limit, base)
   3974                      axis=axis, kind=kind, loffset=loffset,
   3975                      convention=convention,
-> 3976                      base=base)
   3977         return _maybe_process_deprecations(r,
   3978                                            how=how,

/Users/Mike/anaconda/lib/python2.7/site-packages/pandas/tseries/resample.pyc in resample(obj, kind, **kwds)
    896     """ create a TimeGrouper and return our resampler """
    897     tg = TimeGrouper(**kwds)
--> 898     return tg._get_resampler(obj, kind=kind)
    899 resample.__doc__ = Resampler.__doc__
    900 

/Users/Mike/anaconda/lib/python2.7/site-packages/pandas/tseries/resample.pyc in _get_resampler(self, obj, kind)
   1010         raise TypeError("Only valid with DatetimeIndex, "
   1011                         "TimedeltaIndex or PeriodIndex, "
-> 1012                         "but got an instance of %r" % type(ax).__name__)
   1013 
   1014     def _get_grouper(self, obj):

TypeError: Only valid with DatetimeIndex, TimedeltaIndex or PeriodIndex, but got an instance of 'Index'

In [ ]: