group_by broken #23
Description
I haven't been able to use anything with group_by in it since upgrading to pandas to 1.1.0+
pd.DataFrame({'a':range(10)}) >> count('a==0')
---------------------------------------------------------------------------
TypeError Traceback (most recent call last)
<ipython-input-4-8092b63f45c6> in <module>
----> 1 pd.DataFrame({'a':range(10)}) >> count('a==0')
/usr/local/lib/python3.7/site-packages/plydata/operators.py in __rrshift__(self, other)
122 self.data = other
123 func = get_verb_function(self.data, self.__class__.__name__)
--> 124 return func(self)
125
126 def __call__(self, data):
/usr/local/lib/python3.7/site-packages/plydata/dataframe/helpers.py in count(verb)
63 verb.add_ = True
64 verb.data = group_by(verb)
---> 65 data = tally(verb)
66
67 # Restore original groups
/usr/local/lib/python3.7/site-packages/plydata/dataframe/helpers.py in tally(verb)
49
50 verb.expressions = [Expression(stmt, 'n')]
---> 51 data = summarize(verb)
52 if verb.sort:
53 data = data.sort_values(by='n', ascending=False)
/usr/local/lib/python3.7/site-packages/plydata/dataframe/one_table.py in summarize(verb)
169 verb,
170 keep_index=False,
--> 171 keep_groups=False).process()
172 return data
173
/usr/local/lib/python3.7/site-packages/plydata/dataframe/common.py in process(self)
217 gdfs = self._get_group_dataframes()
218 egdfs = self._evaluate_expressions(gdfs)
--> 219 edata = self._concat(egdfs)
220 return edata
221
/usr/local/lib/python3.7/site-packages/plydata/dataframe/common.py in _concat(self, egdfs)
307 Evaluated data
308 """
--> 309 egdfs = list(egdfs)
310 edata = pd.concat(egdfs, axis=0, ignore_index=False, copy=False)
311
/usr/local/lib/python3.7/site-packages/plydata/dataframe/common.py in <genexpr>(.0)
264 Result dataframes for each group
265 """
--> 266 return (self._evaluate_group_dataframe(gdf) for gdf in gdfs)
267
268 def _evaluate_group_dataframe(self, gdf):
/usr/local/lib/python3.7/site-packages/plydata/dataframe/common.py in _evaluate_group_dataframe(self, gdf)
290 else:
291 _create_column(data, expr.column, value)
--> 292 data = _add_group_columns(data, gdf)
293 return data
294
/usr/local/lib/python3.7/site-packages/plydata/dataframe/common.py in _add_group_columns(data, gdf)
57 n = len(data)
58 if isinstance(gdf, GroupedDataFrame):
---> 59 for i, col in enumerate(gdf.plydata_groups):
60 if col not in data:
61 group_values = [gdf[col].iloc[0]] * n
TypeError: 'NoneType' object is not iterable