add more tests

Author: jorisvandenbossche

pandas/tests/extension/base/setitem.py

@@ -357,6 +357,20 @@ def test_setitem_with_expansion_dataframe_column(self, data, full_indexer):
 
         self.assert_frame_equal(result, expected)
 
+    def test_setitem_with_expansion_row(self, data, na_value):
+        df = pd.DataFrame({"data": data[:1]})
+
+        df.loc[1, "data"] = data[1]
+        expected = pd.DataFrame({"data": data[:2]})
+        self.assert_frame_equal(df, expected)
+
+        # https://github.com/pandas-dev/pandas/issues/47284
+        df.loc[2, "data"] = na_value
+        expected = pd.DataFrame(
+            {"data": pd.Series([data[0], data[1], na_value], dtype=data.dtype)}
+        )
+        self.assert_frame_equal(df, expected)
+
     def test_setitem_series(self, data, full_indexer):
         # https://github.com/pandas-dev/pandas/issues/32395
         ser = pd.Series(data, name="data")

pandas/tests/reshape/concat/test_concat.py

@@ -792,3 +792,12 @@ def test_concat_ignore_all_na_object_float(empty_dtype, df_dtype):
             df_dtype = "float64"
     expected = DataFrame({"foo": [None, 1, 2], "bar": [None, 1, 2]}, dtype=df_dtype)
     tm.assert_frame_equal(result, expected)
+
+
+def test_concat_ignore_empty_from_reindex():
+    # https://github.com/pandas-dev/pandas/pull/43507#issuecomment-920375856
+    df1 = DataFrame({"a": [1], "b": [pd.Timestamp("2012-01-01")]})
+    df2 = DataFrame({"a": [2]})
+
+    result = concat([df1, df2.reindex(columns=df1.columns)])
+    tm.assert_frame_equal(result, df1)