From f8c22025d2273e35a0f8d5e3677968b4191eb97c Mon Sep 17 00:00:00 2001
From: Margaret Sy <margaretsy1016@gmail.com>
Date: Mon, 22 May 2017 15:59:48 -0700
Subject: [PATCH 01/13] BUG: .iloc[:] and .loc[:] return copy of original
 object (#13873)

This is consistent with the behavior of [:] on a list
https://docs.python.org/2/tutorial/introduction.html#lists
https://docs.python.org/3/tutorial/introduction.html#lists
---
 pandas/core/indexing.py            | 6 +++---
 pandas/tests/indexing/test_iloc.py | 5 +++++
 pandas/tests/indexing/test_loc.py  | 5 +++++
 3 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/pandas/core/indexing.py b/pandas/core/indexing.py
index 50f2f9b52e111..0437d91a94bb6 100755
--- a/pandas/core/indexing.py
+++ b/pandas/core/indexing.py
@@ -1250,7 +1250,7 @@ def _get_slice_axis(self, slice_obj, axis=0):
         obj = self.obj
 
         if not need_slice(slice_obj):
-            return obj
+            return obj.copy()
         indexer = self._convert_slice_indexer(slice_obj, axis)
 
         if isinstance(indexer, slice):
@@ -1349,7 +1349,7 @@ def _get_slice_axis(self, slice_obj, axis=0):
         """ this is pretty simple as we just have to deal with labels """
         obj = self.obj
         if not need_slice(slice_obj):
-            return obj
+            return obj.copy()
 
         labels = obj._get_axis(axis)
         indexer = labels.slice_indexer(slice_obj.start, slice_obj.stop,
@@ -1690,7 +1690,7 @@ def _get_slice_axis(self, slice_obj, axis=0):
         obj = self.obj
 
         if not need_slice(slice_obj):
-            return obj
+            return obj.copy()
 
         slice_obj = self._convert_slice_indexer(slice_obj, axis)
         if isinstance(slice_obj, slice):
diff --git a/pandas/tests/indexing/test_iloc.py b/pandas/tests/indexing/test_iloc.py
index af4b9e1f0cc25..9f647819438fa 100644
--- a/pandas/tests/indexing/test_iloc.py
+++ b/pandas/tests/indexing/test_iloc.py
@@ -591,3 +591,8 @@ def test_iloc_empty_list_indexer_is_ok(self):
         tm.assert_frame_equal(df.iloc[[]], df.iloc[:0, :],
                               check_index_type=True,
                               check_column_type=True)
+
+    def test_loc_identity_slice_returns_new_object(self):
+        # GH13873
+        df = DataFrame({'a': [1, 3, 5], 'b': [2, 4, 6]})
+        assert not df.iloc[:] is df
diff --git a/pandas/tests/indexing/test_loc.py b/pandas/tests/indexing/test_loc.py
index fe2318be72eda..4c7250707da86 100644
--- a/pandas/tests/indexing/test_loc.py
+++ b/pandas/tests/indexing/test_loc.py
@@ -630,3 +630,8 @@ def test_loc_empty_list_indexer_is_ok(self):
         tm.assert_frame_equal(df.loc[[]], df.iloc[:0, :],
                               check_index_type=True,
                               check_column_type=True)
+
+    def test_loc_identity_slice_returns_new_object(self):
+        # GH13873
+        df = DataFrame({'a': [1, 3, 5], 'b': [2, 4, 6]})
+        assert not df.loc[:] is df

From 84f2d5d1ef4aac28bf772619ec25b19f03f06780 Mon Sep 17 00:00:00 2001
From: Margaret Sy <margaretsy1016@gmail.com>
Date: Mon, 22 May 2017 16:58:39 -0700
Subject: [PATCH 02/13] iloc and loc return new object when slice is a tuple

---
 pandas/core/indexing.py            | 5 ++---
 pandas/tests/indexing/test_iloc.py | 2 ++
 pandas/tests/indexing/test_loc.py  | 2 ++
 3 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/pandas/core/indexing.py b/pandas/core/indexing.py
index 0437d91a94bb6..fd43b27e17610 100755
--- a/pandas/core/indexing.py
+++ b/pandas/core/indexing.py
@@ -845,7 +845,7 @@ def _getitem_tuple(self, tup):
             return self._multi_take(tup)
 
         # no shortcut needed
-        retval = self.obj
+        retval = self.obj.copy()
         for i, key in enumerate(tup):
             if i >= self.obj.ndim:
                 raise IndexingError('Too many indexers')
@@ -854,7 +854,6 @@ def _getitem_tuple(self, tup):
                 continue
 
             retval = getattr(retval, self.name)._getitem_axis(key, axis=i)
-
         return retval
 
     def _multi_take_opportunity(self, tup):
@@ -1665,7 +1664,7 @@ def _getitem_tuple(self, tup):
         except:
             pass
 
-        retval = self.obj
+        retval = self.obj.copy()
         axis = 0
         for i, key in enumerate(tup):
             if i >= self.obj.ndim:
diff --git a/pandas/tests/indexing/test_iloc.py b/pandas/tests/indexing/test_iloc.py
index 9f647819438fa..70c7f673adf84 100644
--- a/pandas/tests/indexing/test_iloc.py
+++ b/pandas/tests/indexing/test_iloc.py
@@ -596,3 +596,5 @@ def test_loc_identity_slice_returns_new_object(self):
         # GH13873
         df = DataFrame({'a': [1, 3, 5], 'b': [2, 4, 6]})
         assert not df.iloc[:] is df
+        assert not df.iloc[:,:] is df
+        assert not df.iloc[pd.IndexSlice[:, :]] is df
diff --git a/pandas/tests/indexing/test_loc.py b/pandas/tests/indexing/test_loc.py
index 4c7250707da86..d86cf1fbc5520 100644
--- a/pandas/tests/indexing/test_loc.py
+++ b/pandas/tests/indexing/test_loc.py
@@ -635,3 +635,5 @@ def test_loc_identity_slice_returns_new_object(self):
         # GH13873
         df = DataFrame({'a': [1, 3, 5], 'b': [2, 4, 6]})
         assert not df.loc[:] is df
+        assert not df.loc[:,:] is df
+        assert not df.loc[pd.IndexSlice[:, :]] is df

From fd47ef0389f061ad4c167ec94e827c17061113c1 Mon Sep 17 00:00:00 2001
From: Margaret Sy <margaretsy1016@gmail.com>
Date: Mon, 22 May 2017 17:11:59 -0700
Subject: [PATCH 03/13] Revert "iloc and loc return new object when slice is a
 tuple"

This reverts commit 5daffa8a240f165cdaf74f70c5cb48fc4a0aa128.
---
 pandas/core/indexing.py            | 5 +++--
 pandas/tests/indexing/test_iloc.py | 2 --
 pandas/tests/indexing/test_loc.py  | 2 --
 3 files changed, 3 insertions(+), 6 deletions(-)

diff --git a/pandas/core/indexing.py b/pandas/core/indexing.py
index fd43b27e17610..0437d91a94bb6 100755
--- a/pandas/core/indexing.py
+++ b/pandas/core/indexing.py
@@ -845,7 +845,7 @@ def _getitem_tuple(self, tup):
             return self._multi_take(tup)
 
         # no shortcut needed
-        retval = self.obj.copy()
+        retval = self.obj
         for i, key in enumerate(tup):
             if i >= self.obj.ndim:
                 raise IndexingError('Too many indexers')
@@ -854,6 +854,7 @@ def _getitem_tuple(self, tup):
                 continue
 
             retval = getattr(retval, self.name)._getitem_axis(key, axis=i)
+
         return retval
 
     def _multi_take_opportunity(self, tup):
@@ -1664,7 +1665,7 @@ def _getitem_tuple(self, tup):
         except:
             pass
 
-        retval = self.obj.copy()
+        retval = self.obj
         axis = 0
         for i, key in enumerate(tup):
             if i >= self.obj.ndim:
diff --git a/pandas/tests/indexing/test_iloc.py b/pandas/tests/indexing/test_iloc.py
index 70c7f673adf84..9f647819438fa 100644
--- a/pandas/tests/indexing/test_iloc.py
+++ b/pandas/tests/indexing/test_iloc.py
@@ -596,5 +596,3 @@ def test_loc_identity_slice_returns_new_object(self):
         # GH13873
         df = DataFrame({'a': [1, 3, 5], 'b': [2, 4, 6]})
         assert not df.iloc[:] is df
-        assert not df.iloc[:,:] is df
-        assert not df.iloc[pd.IndexSlice[:, :]] is df
diff --git a/pandas/tests/indexing/test_loc.py b/pandas/tests/indexing/test_loc.py
index d86cf1fbc5520..4c7250707da86 100644
--- a/pandas/tests/indexing/test_loc.py
+++ b/pandas/tests/indexing/test_loc.py
@@ -635,5 +635,3 @@ def test_loc_identity_slice_returns_new_object(self):
         # GH13873
         df = DataFrame({'a': [1, 3, 5], 'b': [2, 4, 6]})
         assert not df.loc[:] is df
-        assert not df.loc[:,:] is df
-        assert not df.loc[pd.IndexSlice[:, :]] is df

From ef0af94bd366c5da16c3d3c1b66ae972d5ef3c2b Mon Sep 17 00:00:00 2001
From: Margaret Sy <margaretsy1016@gmail.com>
Date: Tue, 23 May 2017 10:20:04 -0700
Subject: [PATCH 04/13] return a shallow copy instead of deep copy

---
 pandas/core/indexing.py            | 6 +++---
 pandas/tests/indexing/test_iloc.py | 8 ++++++--
 pandas/tests/indexing/test_loc.py  | 8 ++++++--
 3 files changed, 15 insertions(+), 7 deletions(-)

diff --git a/pandas/core/indexing.py b/pandas/core/indexing.py
index 0437d91a94bb6..eb24f32cfbe81 100755
--- a/pandas/core/indexing.py
+++ b/pandas/core/indexing.py
@@ -1250,7 +1250,7 @@ def _get_slice_axis(self, slice_obj, axis=0):
         obj = self.obj
 
         if not need_slice(slice_obj):
-            return obj.copy()
+            return obj.copy(deep=False)
         indexer = self._convert_slice_indexer(slice_obj, axis)
 
         if isinstance(indexer, slice):
@@ -1349,7 +1349,7 @@ def _get_slice_axis(self, slice_obj, axis=0):
         """ this is pretty simple as we just have to deal with labels """
         obj = self.obj
         if not need_slice(slice_obj):
-            return obj.copy()
+            return obj.copy(deep=False)
 
         labels = obj._get_axis(axis)
         indexer = labels.slice_indexer(slice_obj.start, slice_obj.stop,
@@ -1690,7 +1690,7 @@ def _get_slice_axis(self, slice_obj, axis=0):
         obj = self.obj
 
         if not need_slice(slice_obj):
-            return obj.copy()
+            return obj.copy(deep=False)
 
         slice_obj = self._convert_slice_indexer(slice_obj, axis)
         if isinstance(slice_obj, slice):
diff --git a/pandas/tests/indexing/test_iloc.py b/pandas/tests/indexing/test_iloc.py
index 9f647819438fa..edd0678c2b59a 100644
--- a/pandas/tests/indexing/test_iloc.py
+++ b/pandas/tests/indexing/test_iloc.py
@@ -594,5 +594,9 @@ def test_iloc_empty_list_indexer_is_ok(self):
 
     def test_loc_identity_slice_returns_new_object(self):
         # GH13873
-        df = DataFrame({'a': [1, 3, 5], 'b': [2, 4, 6]})
-        assert not df.iloc[:] is df
+        df = DataFrame({'a': [1, 2, 3]})
+        result = df.iloc[:]
+        assert not result is df
+        # should be a shallow copy
+        df['a'] = [4, 4, 4]
+        assert (result['a'] == 4).all()
diff --git a/pandas/tests/indexing/test_loc.py b/pandas/tests/indexing/test_loc.py
index 4c7250707da86..2ee32f69da394 100644
--- a/pandas/tests/indexing/test_loc.py
+++ b/pandas/tests/indexing/test_loc.py
@@ -633,5 +633,9 @@ def test_loc_empty_list_indexer_is_ok(self):
 
     def test_loc_identity_slice_returns_new_object(self):
         # GH13873
-        df = DataFrame({'a': [1, 3, 5], 'b': [2, 4, 6]})
-        assert not df.loc[:] is df
+        df = DataFrame({'a': [1, 2, 3]})
+        result = df.loc[:]
+        assert not result is df
+        # should be a shallow copy
+        df['a'] = [4, 4, 4]
+        assert (result['a'] == 4).all()

From cd4980ea1a525f3853f4a0d1967ab46680a1be2c Mon Sep 17 00:00:00 2001
From: Margaret Sy <margaretsy1016@gmail.com>
Date: Tue, 23 May 2017 14:17:56 -0700
Subject: [PATCH 05/13] _getitem_lowerdim won't return copy of object if called
 with [:]

---
 pandas/core/indexing.py | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/pandas/core/indexing.py b/pandas/core/indexing.py
index eb24f32cfbe81..ae0aaf98fdf02 100755
--- a/pandas/core/indexing.py
+++ b/pandas/core/indexing.py
@@ -988,6 +988,10 @@ def _getitem_lowerdim(self, tup):
                     if len(new_key) == 1:
                         new_key, = new_key
 
+                # Slices should return views, but calling iloc/loc with a null
+                # slice returns a new object.
+                if is_null_slice(new_key):
+                    return section
                 # This is an elided recursive call to iloc/loc/etc'
                 return getattr(section, self.name)[new_key]
 

From 6771c595f10f27d1ecb5d107768680ff753d8a07 Mon Sep 17 00:00:00 2001
From: Margaret Sy <margaretsy1016@gmail.com>
Date: Tue, 23 May 2017 14:43:59 -0700
Subject: [PATCH 06/13] Add item for indexers returning new object instead of
 original

---
 doc/source/whatsnew/v0.21.0.txt | 1 +
 1 file changed, 1 insertion(+)

diff --git a/doc/source/whatsnew/v0.21.0.txt b/doc/source/whatsnew/v0.21.0.txt
index 79f2816f43a6f..0c6a332c8a1b4 100644
--- a/doc/source/whatsnew/v0.21.0.txt
+++ b/doc/source/whatsnew/v0.21.0.txt
@@ -97,6 +97,7 @@ Conversion
 Indexing
 ^^^^^^^^
 
+- When called with a null slice (i.e. ``df.iloc[:]``), the``iloc`` and ``loc`` indexers return a shallow copy of the original object. Previously they returned the original object. (:issue:`13873`).
 
 
 I/O

From a405a108beaf7732df4cfe5990912c61152ff3f7 Mon Sep 17 00:00:00 2001
From: Margaret Sy <margaretsy1016@gmail.com>
Date: Tue, 23 May 2017 14:48:59 -0700
Subject: [PATCH 07/13] grammar correction - i.e. to e.g.

---
 doc/source/whatsnew/v0.21.0.txt | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/doc/source/whatsnew/v0.21.0.txt b/doc/source/whatsnew/v0.21.0.txt
index 0c6a332c8a1b4..d6b699abdba2d 100644
--- a/doc/source/whatsnew/v0.21.0.txt
+++ b/doc/source/whatsnew/v0.21.0.txt
@@ -97,7 +97,7 @@ Conversion
 Indexing
 ^^^^^^^^
 
-- When called with a null slice (i.e. ``df.iloc[:]``), the``iloc`` and ``loc`` indexers return a shallow copy of the original object. Previously they returned the original object. (:issue:`13873`).
+- When called with a null slice (e.g. ``df.iloc[:]``), the``iloc`` and ``loc`` indexers return a shallow copy of the original object. Previously they returned the original object. (:issue:`13873`).
 
 
 I/O

From ad1be5d77ac1cd3362b753a63a245a3f5afcbf29 Mon Sep 17 00:00:00 2001
From: Margaret Sy <margaretsy1016@gmail.com>
Date: Thu, 25 May 2017 11:06:42 -0700
Subject: [PATCH 08/13] fix some spacing and linting errors

---
 pandas/tests/indexing/test_iloc.py | 3 ++-
 pandas/tests/indexing/test_loc.py  | 3 ++-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/pandas/tests/indexing/test_iloc.py b/pandas/tests/indexing/test_iloc.py
index edd0678c2b59a..23f8223f60607 100644
--- a/pandas/tests/indexing/test_iloc.py
+++ b/pandas/tests/indexing/test_iloc.py
@@ -596,7 +596,8 @@ def test_loc_identity_slice_returns_new_object(self):
         # GH13873
         df = DataFrame({'a': [1, 2, 3]})
         result = df.iloc[:]
-        assert not result is df
+        assert result is not df
+
         # should be a shallow copy
         df['a'] = [4, 4, 4]
         assert (result['a'] == 4).all()
diff --git a/pandas/tests/indexing/test_loc.py b/pandas/tests/indexing/test_loc.py
index 2ee32f69da394..411f1dfe88d86 100644
--- a/pandas/tests/indexing/test_loc.py
+++ b/pandas/tests/indexing/test_loc.py
@@ -635,7 +635,8 @@ def test_loc_identity_slice_returns_new_object(self):
         # GH13873
         df = DataFrame({'a': [1, 2, 3]})
         result = df.loc[:]
-        assert not result is df
+        assert result is not df
+
         # should be a shallow copy
         df['a'] = [4, 4, 4]
         assert (result['a'] == 4).all()

From c139b479d83e3c48ed3b636b6a249e0e3540288e Mon Sep 17 00:00:00 2001
From: Margaret Sy <margaretsy1016@gmail.com>
Date: Thu, 25 May 2017 11:11:40 -0700
Subject: [PATCH 09/13] remove indexer type from test name

---
 pandas/tests/indexing/test_iloc.py | 2 +-
 pandas/tests/indexing/test_loc.py  | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/pandas/tests/indexing/test_iloc.py b/pandas/tests/indexing/test_iloc.py
index 23f8223f60607..b62c252e366de 100644
--- a/pandas/tests/indexing/test_iloc.py
+++ b/pandas/tests/indexing/test_iloc.py
@@ -592,7 +592,7 @@ def test_iloc_empty_list_indexer_is_ok(self):
                               check_index_type=True,
                               check_column_type=True)
 
-    def test_loc_identity_slice_returns_new_object(self):
+    def test_identity_slice_returns_new_object(self):
         # GH13873
         df = DataFrame({'a': [1, 2, 3]})
         result = df.iloc[:]
diff --git a/pandas/tests/indexing/test_loc.py b/pandas/tests/indexing/test_loc.py
index 411f1dfe88d86..d33eae59f45f5 100644
--- a/pandas/tests/indexing/test_loc.py
+++ b/pandas/tests/indexing/test_loc.py
@@ -631,7 +631,7 @@ def test_loc_empty_list_indexer_is_ok(self):
                               check_index_type=True,
                               check_column_type=True)
 
-    def test_loc_identity_slice_returns_new_object(self):
+    def test_identity_slice_returns_new_object(self):
         # GH13873
         df = DataFrame({'a': [1, 2, 3]})
         result = df.loc[:]

From 7634d3bd3e2a9db1a288e90d26995a9fe7d257d9 Mon Sep 17 00:00:00 2001
From: Margaret Sy <margaretsy1016@gmail.com>
Date: Thu, 25 May 2017 11:48:36 -0700
Subject: [PATCH 10/13] add tests for Series

---
 pandas/tests/indexing/test_iloc.py | 18 +++++++++++++-----
 pandas/tests/indexing/test_loc.py  | 18 +++++++++++++-----
 2 files changed, 26 insertions(+), 10 deletions(-)

diff --git a/pandas/tests/indexing/test_iloc.py b/pandas/tests/indexing/test_iloc.py
index b62c252e366de..769cf8ec395dd 100644
--- a/pandas/tests/indexing/test_iloc.py
+++ b/pandas/tests/indexing/test_iloc.py
@@ -594,10 +594,18 @@ def test_iloc_empty_list_indexer_is_ok(self):
 
     def test_identity_slice_returns_new_object(self):
         # GH13873
-        df = DataFrame({'a': [1, 2, 3]})
-        result = df.iloc[:]
-        assert result is not df
+        original_df = DataFrame({'a': [1, 2, 3]})
+        sliced_df = original_df.iloc[:]
+        assert sliced_df is not original_df
 
         # should be a shallow copy
-        df['a'] = [4, 4, 4]
-        assert (result['a'] == 4).all()
+        original_df['a'] = [4, 4, 4]
+        assert (sliced_df['a'] == 4).all()
+
+        original_series = Series([1, 2, 3, 4, 5, 6])
+        sliced_series = original_series.iloc[:]
+        assert sliced_series is not original_series
+
+        # should also be a shallow copy
+        original_series[:3] = [7, 8, 9]
+        assert all(sliced_series[:3] == [7, 8, 9])
diff --git a/pandas/tests/indexing/test_loc.py b/pandas/tests/indexing/test_loc.py
index d33eae59f45f5..44dcbd7affaff 100644
--- a/pandas/tests/indexing/test_loc.py
+++ b/pandas/tests/indexing/test_loc.py
@@ -633,10 +633,18 @@ def test_loc_empty_list_indexer_is_ok(self):
 
     def test_identity_slice_returns_new_object(self):
         # GH13873
-        df = DataFrame({'a': [1, 2, 3]})
-        result = df.loc[:]
-        assert result is not df
+        original_df = DataFrame({'a': [1, 2, 3]})
+        sliced_df = original_df.loc[:]
+        assert sliced_df is not original_df
 
         # should be a shallow copy
-        df['a'] = [4, 4, 4]
-        assert (result['a'] == 4).all()
+        original_df['a'] = [4, 4, 4]
+        assert (sliced_df['a'] == 4).all()
+
+        original_series = Series([1, 2, 3, 4, 5, 6])
+        sliced_series = original_series.loc[:]
+        assert sliced_series is not original_series
+
+        # should also be a shallow copy
+        original_series[:3] = [7, 8, 9]
+        assert all(sliced_series[:3] == [7, 8, 9])

From c78c43c9672a558f3ec0f4c8bc1fb6d330e81f34 Mon Sep 17 00:00:00 2001
From: Margaret Sy <margaretsy1016@gmail.com>
Date: Thu, 25 May 2017 14:10:14 -0700
Subject: [PATCH 11/13] test that df.loc[:,0] returns a view

---
 pandas/tests/indexing/test_loc.py | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/pandas/tests/indexing/test_loc.py b/pandas/tests/indexing/test_loc.py
index 44dcbd7affaff..272e3bd1172e7 100644
--- a/pandas/tests/indexing/test_loc.py
+++ b/pandas/tests/indexing/test_loc.py
@@ -641,10 +641,15 @@ def test_identity_slice_returns_new_object(self):
         original_df['a'] = [4, 4, 4]
         assert (sliced_df['a'] == 4).all()
 
+        # These should not return copies
+        assert original_df is original_df.loc[:, :]
+        df = DataFrame(np.random.randn(10, 4))
+        assert df[0] is df.loc[:,0]
+
+        # Same tests for Series
         original_series = Series([1, 2, 3, 4, 5, 6])
         sliced_series = original_series.loc[:]
         assert sliced_series is not original_series
 
-        # should also be a shallow copy
         original_series[:3] = [7, 8, 9]
         assert all(sliced_series[:3] == [7, 8, 9])

From 3f33c61d3b59519ec8da56b0230e88ae3c1fc880 Mon Sep 17 00:00:00 2001
From: Margaret Sy <margaretsy1016@gmail.com>
Date: Fri, 26 May 2017 20:12:23 -0700
Subject: [PATCH 12/13] fix linting error

---
 pandas/tests/indexing/test_loc.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pandas/tests/indexing/test_loc.py b/pandas/tests/indexing/test_loc.py
index 272e3bd1172e7..571268fba86c8 100644
--- a/pandas/tests/indexing/test_loc.py
+++ b/pandas/tests/indexing/test_loc.py
@@ -644,7 +644,7 @@ def test_identity_slice_returns_new_object(self):
         # These should not return copies
         assert original_df is original_df.loc[:, :]
         df = DataFrame(np.random.randn(10, 4))
-        assert df[0] is df.loc[:,0]
+        assert df[0] is df.loc[:, 0]
 
         # Same tests for Series
         original_series = Series([1, 2, 3, 4, 5, 6])

From d13082430513a0ebcb61f0c4ad79eebeab27194f Mon Sep 17 00:00:00 2001
From: Margaret Sy <margaretsy1016@gmail.com>
Date: Sat, 3 Jun 2017 10:39:10 -0700
Subject: [PATCH 13/13] add tests for direct slicing

---
 pandas/tests/indexing/test_loc.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/pandas/tests/indexing/test_loc.py b/pandas/tests/indexing/test_loc.py
index 571268fba86c8..3e863a59df67e 100644
--- a/pandas/tests/indexing/test_loc.py
+++ b/pandas/tests/indexing/test_loc.py
@@ -636,6 +636,7 @@ def test_identity_slice_returns_new_object(self):
         original_df = DataFrame({'a': [1, 2, 3]})
         sliced_df = original_df.loc[:]
         assert sliced_df is not original_df
+        assert original_df[:] is not original_df
 
         # should be a shallow copy
         original_df['a'] = [4, 4, 4]
@@ -650,6 +651,7 @@ def test_identity_slice_returns_new_object(self):
         original_series = Series([1, 2, 3, 4, 5, 6])
         sliced_series = original_series.loc[:]
         assert sliced_series is not original_series
+        assert original_series[:] is not original_series
 
         original_series[:3] = [7, 8, 9]
         assert all(sliced_series[:3] == [7, 8, 9])