DOC fix incorrect example in DataFrame.to_dict docstring. Close GH19868 (pandas-dev#19915)

Author: Anh Le

pandas/core/frame.py

@@ -958,8 +958,8 @@ def to_dict(self, orient='dict', into=dict):
                 {'col1': [1, 2], 'col2': [0.5, 0.75]}, index=['a', 'b'])
         >>> df
            col1  col2
-        a     1   0.1
-        b     2   0.2
+        a     1   0.50
+        b     2   0.75
         >>> df.to_dict()
         {'col1': {'a': 1, 'b': 2}, 'col2': {'a': 0.5, 'b': 0.75}}