Add new item to API changes describing #16961

alanbato · alanbato · commit cbefc9a04ffd · 2017-07-15T17:28:53.000-05:00
diff --git a/doc/source/whatsnew/v0.21.0.txt b/doc/source/whatsnew/v0.21.0.txt
@@ -108,6 +108,7 @@ Other API Changes
 - ``Index.get_indexer_non_unique()`` now returns a ndarray indexer rather than an ``Index``; this is consistent with ``Index.get_indexer()`` (:issue:`16819`)
 - Removed the ``@slow`` decorator from ``pandas.util.testing``, which caused issues for some downstream packages' test suites. Use ``@pytest.mark.slow`` instead, which achieves the same thing (:issue:`16850`)
 - Moved definition of ``MergeError`` to the ``pandas.errors`` module.
+- Setting on a column with a scalar value and no index now raises a ``ValueError`` (:issue:`16823`)
 
 
 .. _whatsnew_0210.deprecations:
