DOC: improve description of the example which dataframe has two rows (#36971)

* fix issue 36970

improve description of the examplewhich dataframe has two rows

* improve description of example

improve description of the example which dataframe has two rows

* improve description of the example describing mode operation.

* remove trailing extra line

* preserve newline

Co-authored-by: yonas kassa <[email protected]>
Co-authored-by: Marco Gorelli <[email protected]>

Author: 3 people

pandas/core/frame.py

@@ -8950,8 +8950,8 @@ def mode(self, axis=0, numeric_only=False, dropna=True) -> DataFrame:
         ostrich       bird     2    NaN
 
         By default, missing values are not considered, and the mode of wings
-        are both 0 and 2. The second row of species and legs contains ``NaN``,
-        because they have only one mode, but the DataFrame has two rows.
+        are both 0 and 2. Because the resulting DataFrame has two rows,
+        the second row of ``species`` and ``legs`` contains ``NaN``.
 
         >>> df.mode()
           species  legs  wings