Add example

Author: adamjstewart

pandas/core/indexes/multi.py

@@ -1798,13 +1798,26 @@ def to_flat_index(self):
 
         Examples
         --------
+
+        To convert a MultiIndex to an Index:
+
         >>> index = pd.MultiIndex.from_product(
         ...     [['foo', 'bar'], ['baz', 'qux']],
         ...     names=['a', 'b'])
-        >>> index.to_flat_index()
+        >>> index = index.to_flat_index()
+        >>> index
         Index([('foo', 'baz'), ('foo', 'qux'),
                ('bar', 'baz'), ('bar', 'qux')],
               dtype='object')
+
+        To convert an Index back to a MultiIndex:
+
+        >>> pd.MultiIndex.from_tuples(index, names=['a', 'b'])
+        MultiIndex([('foo', 'baz'),
+                    ('foo', 'qux'),
+                    ('bar', 'baz'),
+                    ('bar', 'qux')],
+                   names=['a', 'b'])
         """
         return Index(self._values, tupleize_cols=False)