fixed pandas bug

dios/dios.py

@@ -190,7 +190,7 @@ class DictOfSeries:
         else:
             # work on columns
             new = self.copy_empty(columns=False)
-            new._data = self._data[key]
+            new._data = self._data.loc[key]
         return new
 
     def _slice(self, key):
@@ -200,7 +200,9 @@ class DictOfSeries:
 
         new = self.copy_empty(columns=False)
         for k in self.columns:
-            new._data.at[k] = self._data.at[k][key]
+            # bug-fix: must be .loc, simple
+            # ser[key] may work positional!
+            new._data.at[k] = self._data.at[k].loc[key]
         return new
 
     def _getitem_bool_dios(self, key):
@@ -235,7 +237,7 @@ class DictOfSeries:
             if isinstance(value, pd.Series):
                 self._insert(key, value)
             else:
-                self._data.at[key].loc[:] = value
+                self._data.at[key][:] = value
 
         else:
             data = self.__getitem__(key)