From a5719e80961f58cf2edb369c08f0c1864b99872d Mon Sep 17 00:00:00 2001
From: Simon Hawkins <simonjayhawkins@gmail.com>
Date: Tue, 14 Apr 2020 20:28:52 +0100
Subject: [PATCH 1/3] CLN: misc cleanups from LGTM

---
 pandas/_testing.py    | 6 ------
 pandas/core/frame.py  | 1 -
 pandas/core/series.py | 1 -
 3 files changed, 8 deletions(-)

diff --git a/pandas/_testing.py b/pandas/_testing.py
index 1f6b645c821c8..e02188f4fb9b1 100644
--- a/pandas/_testing.py
+++ b/pandas/_testing.py
@@ -248,16 +248,10 @@ def write_to_compressed(compression, path, data, dest="test"):
     ValueError : An invalid compression value was passed in.
     """
     if compression == "zip":
-        import zipfile
-
         compress_method = zipfile.ZipFile
     elif compression == "gzip":
-        import gzip
-
         compress_method = gzip.GzipFile
     elif compression == "bz2":
-        import bz2
-
         compress_method = bz2.BZ2File
     elif compression == "xz":
         compress_method = _get_lzma_file(lzma)
diff --git a/pandas/core/frame.py b/pandas/core/frame.py
index d19f1a263f71a..dd1aabaa342ff 100644
--- a/pandas/core/frame.py
+++ b/pandas/core/frame.py
@@ -8216,7 +8216,6 @@ def blk_func(values):
                     result = result.iloc[0].rename(None)
                 return result
 
-        data = self
         if numeric_only is None:
             data = self
             values = data.values
diff --git a/pandas/core/series.py b/pandas/core/series.py
index 3f5927828e541..66bccb8840cd2 100644
--- a/pandas/core/series.py
+++ b/pandas/core/series.py
@@ -276,7 +276,6 @@ def __init__(
                         "Cannot construct a Series from an ndarray with "
                         "compound dtype.  Use DataFrame instead."
                     )
-                pass
             elif isinstance(data, ABCSeries):
                 if index is None:
                     index = data.index

From 66c6768d7130ecee414beffa13ff099610e2193a Mon Sep 17 00:00:00 2001
From: Simon Hawkins <simonjayhawkins@gmail.com>
Date: Wed, 22 Apr 2020 20:19:26 +0100
Subject: [PATCH 2/3] TST: pd.concat on two (or more) series produces all-NaN
 dataframe

---
 pandas/tests/reshape/test_concat.py | 34 +++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)

diff --git a/pandas/tests/reshape/test_concat.py b/pandas/tests/reshape/test_concat.py
index bccae2c4c2772..c4025640bb49f 100644
--- a/pandas/tests/reshape/test_concat.py
+++ b/pandas/tests/reshape/test_concat.py
@@ -2768,3 +2768,37 @@ def test_concat_copy_index(test_series, axis):
         comb = concat([df, df], axis=axis, copy=True)
         assert comb.index is not df.index
         assert comb.columns is not df.columns
+
+
+def test_concat_multiindex_datetime_object_index():
+    # https://github.com/pandas-dev/pandas/issues/11058
+    s = Series(
+        ["a", "b"],
+        index=MultiIndex.from_arrays(
+            [[1, 2], Index([dt.date(2013, 1, 1), dt.date(2014, 1, 1)], dtype="object")],
+            names=["first", "second"],
+        ),
+    )
+    s2 = Series(
+        ["a", "b"],
+        index=MultiIndex.from_arrays(
+            [[1, 2], Index([dt.date(2013, 1, 1), dt.date(2015, 1, 1)], dtype="object")],
+            names=["first", "second"],
+        ),
+    )
+    expected = DataFrame(
+        [["a", "a"], ["b", np.nan], [np.nan, "b"]],
+        index=MultiIndex.from_arrays(
+            [
+                [1, 2, 2],
+                DatetimeIndex(
+                    ["2013-01-01", "2014-01-01", "2015-01-01"],
+                    dtype="datetime64[ns]",
+                    freq=None,
+                ),
+            ],
+            names=["first", "second"],
+        ),
+    )
+    result = concat([s, s2], axis=1)
+    tm.assert_frame_equal(result, expected)

From 9fab09250b48480beea6dee9e36151e01b738e1f Mon Sep 17 00:00:00 2001
From: Simon Hawkins <simonjayhawkins@gmail.com>
Date: Wed, 22 Apr 2020 20:21:35 +0100
Subject: [PATCH 3/3] Revert "CLN: misc cleanups from LGTM"

This reverts commit a5719e80961f58cf2edb369c08f0c1864b99872d.
---
 pandas/_testing.py    | 6 ++++++
 pandas/core/frame.py  | 1 +
 pandas/core/series.py | 1 +
 3 files changed, 8 insertions(+)

diff --git a/pandas/_testing.py b/pandas/_testing.py
index 21e74dafcc944..4f957b7a55e3a 100644
--- a/pandas/_testing.py
+++ b/pandas/_testing.py
@@ -279,10 +279,16 @@ def write_to_compressed(compression, path, data, dest="test"):
     ValueError : An invalid compression value was passed in.
     """
     if compression == "zip":
+        import zipfile
+
         compress_method = zipfile.ZipFile
     elif compression == "gzip":
+        import gzip
+
         compress_method = gzip.GzipFile
     elif compression == "bz2":
+        import bz2
+
         compress_method = bz2.BZ2File
     elif compression == "xz":
         compress_method = _get_lzma_file(lzma)
diff --git a/pandas/core/frame.py b/pandas/core/frame.py
index d0276af2e9948..202cb6488446e 100644
--- a/pandas/core/frame.py
+++ b/pandas/core/frame.py
@@ -8218,6 +8218,7 @@ def blk_func(values):
                     result = result.iloc[0].rename(None)
                 return result
 
+        data = self
         if numeric_only is None:
             data = self
             values = data.values
diff --git a/pandas/core/series.py b/pandas/core/series.py
index a9db60f23f2e2..9ef865a964123 100644
--- a/pandas/core/series.py
+++ b/pandas/core/series.py
@@ -275,6 +275,7 @@ def __init__(
                         "Cannot construct a Series from an ndarray with "
                         "compound dtype.  Use DataFrame instead."
                     )
+                pass
             elif isinstance(data, ABCSeries):
                 if index is None:
                     index = data.index