BUG: GH15420 - _rank private method on Categorical

Author: jeet63

pandas/core/algorithms.py

@@ -598,35 +598,28 @@ def mode(values):
 def rank(values, axis=0, method='average', na_option='keep',
          ascending=True, pct=False):
     """
-        Compute numerical data ranks (1 through n) along axis. Equal values are
-        assigned a rank that is the average of the ranks of those values
+        Rank the values along a given axis.
 
         Parameters
         ----------
-        axis : {0 or 'index', 1 or 'columns'}, default 0
-            index to direct ranking
-        method : {'average', 'min', 'max', 'first', 'dense'}
-            * average: average rank of group
-            * min: lowest rank in group
-            * max: highest rank in group
-            * first: ranks assigned in order they appear in the array
-            * dense: like 'min', but rank always increases by 1 between groups
-        numeric_only : boolean, default None
-            Include only float, int, boolean data. Valid only for DataFrame or
-            Panel objects
-        na_option : {'keep', 'top', 'bottom'}
-            * keep: leave NA values where they are
-            * top: smallest rank if ascending
-            * bottom: smallest rank if descending
+        values : array-like
+            Array whose values will be ranked. The number of dimensions in this
+            array must not exceed 2.
+        axis : int, default 0
+            Axis over which to perform rankings.
+        method : {'average', 'min', 'max', 'first', 'dense'}, default 'average'
+            The method by which tiebreaks are broken during the ranking.
+        na_option : {'keep', 'top'}, default 'keep'
+            The method by which NaNs are placed in the ranking.
+            - ``keep``: rank each NaN value with a NaN ranking
+            - ``top``: replace each NaN with either +/- inf so that they
+                       there are ranked at the top
         ascending : boolean, default True
-            False for ranks by high (1) to low (N)
+            Whether or not the elements should be ranked in ascending order.
         pct : boolean, default False
-            Computes percentage rank of data
-
-        Returns
-        -------
-        ranks : same type as caller
-        """
+            Whether or not to the display the returned rankings in integer form
+            (e.g. 1, 2, 3) or in percentile form (e.g. 0.333..., 0.666..., 1).
+    """
     if is_categorical(values):
         ranks = values._rank(axis=axis, method=method, ascending=ascending,
                              na_option=na_option, pct=pct)