Removing uneeded changes

Mistakenly added changes carried out in v0.19 to v0.20

Author: m-charlton

doc/source/whatsnew/v0.20.0.txt

@@ -43,15 +43,27 @@ fixed-width text files, and :func:`read_excel` for parsing Excel files.
    pd.read_fwf(StringIO(data)).dtypes
    pd.read_fwf(StringIO(data), dtype={'a':'float64', 'b':'object'}).dtypes
 
-You can now pass a dictionary mapping column names to desired data types for that
-column to :meth:`~DataFrame.astype`.
+.. _whatsnew_0200.enhancements.groupby_access:
+
+Groupby Enhancements
+^^^^^^^^^^^^^^^^^^^^
+
+Strings passed to ``DataFrame.groupby()`` as the ``by`` parameter may now reference either column names or index level names (:issue:`5677`)
 
 .. ipython:: python
 
-   dft = pd.DataFrame({'a': [1,2,3], 'b': [4,5,6], 'c': [7, 8, 9]})
-   dft = dft.astype({'a': np.float64, 'c': np.uint8})
-   dft
-   dft.dtypes
+   arrays = [['bar', 'bar', 'baz', 'baz', 'foo', 'foo', 'qux', 'qux'],
+             ['one', 'two', 'one', 'two', 'one', 'two', 'one', 'two']]
+
+   index = pd.MultiIndex.from_arrays(arrays, names=['first', 'second'])
+
+   df = pd.DataFrame({'A': [1, 1, 1, 1, 2, 2, 3, 3],
+                      'B': np.arange(8)},
+                     index=index)
+   df
+
+   df.groupby(['second', 'A']).sum()
+
 
 .. _whatsnew_0200.enhancements.other: