Clean docstrings

* Add periods

* Realign descriptions

pandas/core/generic.py

@@ -3966,25 +3966,25 @@ def add_suffix(self, suffix):
     def sort_values(self, by=None, axis=0, ascending=True, inplace=False,
                     kind='quicksort', na_position='last'):
         """
-        Sort by the values along either axis
+        Sort by the values along either axis.
 
         Parameters
         ----------%(optional_by)s
         axis : %(axes_single_arg)s, default 0
-             Axis to be sorted
+             Axis to be sorted.
         ascending : bool or list of bool, default True
              Sort ascending vs. descending. Specify list for multiple sort
              orders.  If this is a list of bools, must match the length of
              the by.
         inplace : bool, default False
-             If True, perform operation in-place
+             If True, perform operation in-place.
         kind : {'quicksort', 'mergesort', 'heapsort'}, default 'quicksort'
              Choice of sorting algorithm. See also ndarray.np.sort for more
              information.  `mergesort` is the only stable algorithm. For
              DataFrames, this option is only applied when sorting on a single
              column or label.
         na_position : {'first', 'last'}, default 'last'
-             `first` puts NaNs at the beginning, `last` puts NaNs at the end
+             Puts NaNs at the beginning if `first`; `last` puts NaNs at the end.
 
         Returns
         -------
@@ -4056,28 +4056,28 @@ def sort_values(self, by=None, axis=0, ascending=True, inplace=False,
     def sort_index(self, axis=0, level=None, ascending=True, inplace=False,
                    kind='quicksort', na_position='last', sort_remaining=True):
         """
-        Sort object by labels (along an axis)
+        Sort object by labels (along an axis).
 
         Parameters
         ----------
         axis : %(axes)s to direct sorting
         level : int or level name or list of ints or list of level names
-            If not None, sort on values in specified index level(s)
+            If not None, sort on values in specified index level(s).
         ascending : boolean, default True
-            Sort ascending vs. descending
+            Sort ascending vs. descending.
         inplace : bool, default False
             If True, perform operation in-place
         kind : {'quicksort', 'mergesort', 'heapsort'}, default 'quicksort'
-             Choice of sorting algorithm. See also ndarray.np.sort for more
-             information.  `mergesort` is the only stable algorithm. For
-             DataFrames, this option is only applied when sorting on a single
-             column or label.
+            Choice of sorting algorithm. See also ndarray.np.sort for more
+            information.  `mergesort` is the only stable algorithm. For
+            DataFrames, this option is only applied when sorting on a single
+            column or label.
         na_position : {'first', 'last'}, default 'last'
-             `first` puts NaNs at the beginning, `last` puts NaNs at the end.
-             Not implemented for MultiIndex.
+            Puts NaNs at the beginning if `first`; `last` puts NaNs at the end.
+            Not implemented for MultiIndex.
         sort_remaining : bool, default True
             If True and sorting by level and index is multilevel, sort by other
-            levels too (in order) after sorting by specified level
+            levels too (in order) after sorting by specified level.
 
         Returns
         -------