Implement multiple axis for dropna

python/ray/dataframe/dataframe.py

@@ -776,9 +776,20 @@ def dropna(self, axis=0, how='any', thresh=None, subset=None,
             DataFrame with the dropna applied.
         """
         if is_list_like(axis):
-            raise NotImplementedError(
-                "To contribute to Pandas on Ray, please visit "
-                "github.com/ray-project/ray.")
+            result = self
+            # TODO(kunalgosar): this builds an intermediate dataframe,
+            # which does unnecessary computation
+            for ax in axis:
+                result = result.dropna(
+                    axis=ax, how=how, thresh=thresh, subset=subset)
+            if not inplace:
+                return result
+
+            return self._update_inplace(
+                block_partitions=result._block_partitions,
+                columns=result.columns,
+                index=result.index
+            )
 
         axis = pd.DataFrame()._get_axis_number(axis)
         inplace = validate_bool_kwarg(inplace, "inplace")

python/ray/dataframe/test/test_dataframe.py

@@ -839,6 +839,8 @@ def test_dense_nan_df():
 
     test_dropna(ray_df, pd_df)
     test_dropna_inplace(ray_df, pd_df)
+    test_dropna_multiple_axes(ray_df, pd_df)
+    test_dropna_multiple_axes_inplace(ray_df, pd_df)
 
 
 @pytest.fixture
@@ -1297,16 +1299,17 @@ def test_drop_duplicates():
 
 @pytest.fixture
 def test_dropna(ray_df, pd_df):
-    ray_df_equals_pandas(ray_df.dropna(axis=1, how='all'),
-                         pd_df.dropna(axis=1, how='all'))
+    assert ray_df_equals_pandas(ray_df.dropna(axis=1, how='all'),
+                                pd_df.dropna(axis=1, how='all'))
 
-    ray_df_equals_pandas(ray_df.dropna(axis=1, how='any'),
-                         pd_df.dropna(axis=1, how='any'))
+    assert ray_df_equals_pandas(ray_df.dropna(axis=1, how='any'),
+                                pd_df.dropna(axis=1, how='any'))
 
-    ray_df_equals_pandas(ray_df.dropna(axis=0, how='all'),
-                         pd_df.dropna(axis=0, how='all'))
+    assert ray_df_equals_pandas(ray_df.dropna(axis=0, how='all'),
+                                pd_df.dropna(axis=0, how='all'))
 
-    ray_df_equals_pandas(ray_df.dropna(thresh=2), pd_df.dropna(thresh=2))
+    assert ray_df_equals_pandas(ray_df.dropna(thresh=2),
+                                pd_df.dropna(thresh=2))
 
 
 @pytest.fixture
@@ -1317,12 +1320,43 @@ def test_dropna_inplace(ray_df, pd_df):
     ray_df.dropna(thresh=2, inplace=True)
     pd_df.dropna(thresh=2, inplace=True)
 
-    ray_df_equals_pandas(ray_df, pd_df)
+    assert ray_df_equals_pandas(ray_df, pd_df)
 
     ray_df.dropna(axis=1, how='any', inplace=True)
     pd_df.dropna(axis=1, how='any', inplace=True)
 
-    ray_df_equals_pandas(ray_df, pd_df)
+    assert ray_df_equals_pandas(ray_df, pd_df)
+
+
+@pytest.fixture
+def test_dropna_multiple_axes(ray_df, pd_df):
+    assert ray_df_equals_pandas(
+        ray_df.dropna(how='all', axis=[0, 1]),
+        pd_df.dropna(how='all', axis=[0, 1])
+    )
+    assert ray_df_equals_pandas(
+        ray_df.dropna(how='all', axis=(0, 1)),
+        pd_df.dropna(how='all', axis=(0, 1))
+    )
+
+
+@pytest.fixture
+def test_dropna_multiple_axes_inplace(ray_df, pd_df):
+    ray_df_copy = ray_df.copy()
+    pd_df_copy = pd_df.copy()
+
+    ray_df_copy.dropna(how='all', axis=[0, 1], inplace=True)
+    pd_df_copy.dropna(how='all', axis=[0, 1], inplace=True)
+
+    assert ray_df_equals_pandas(ray_df_copy, pd_df_copy)
+
+    ray_df_copy = ray_df.copy()
+    pd_df_copy = pd_df.copy()
+
+    ray_df_copy.dropna(how='all', axis=(0, 1), inplace=True)
+    pd_df_copy.dropna(how='all', axis=(0, 1), inplace=True)
+
+    assert ray_df_equals_pandas(ray_df_copy, pd_df_copy)
 
 
 def test_duplicated():