From f57c3ad333aad9cebe0a009698219bc740cb5747 Mon Sep 17 00:00:00 2001
From: jeschwar <36767735+jeschwar@users.noreply.github.com>
Date: Fri, 11 Sep 2020 15:56:46 -0600
Subject: [PATCH 1/6] TST: revise LaTeX longtable tests for duplicate List of
 Tables entries (#34360)

---
 pandas/tests/io/formats/test_to_latex.py | 33 ++++++++++++++++++++++++
 1 file changed, 33 insertions(+)

diff --git a/pandas/tests/io/formats/test_to_latex.py b/pandas/tests/io/formats/test_to_latex.py
index a98644250b328..438dbdd98a4b5 100644
--- a/pandas/tests/io/formats/test_to_latex.py
+++ b/pandas/tests/io/formats/test_to_latex.py
@@ -411,6 +411,11 @@ def test_to_latex_longtable(self):
         df = DataFrame({"a": [1, 2], "b": ["b1", "b2"]})
         withindex_result = df.to_latex(longtable=True)
         withindex_expected = r"""\begin{longtable}{lrl}
+\toprule
+{} &  a &   b \\
+\midrule
+\endfirsthead
+
 \toprule
 {} &  a &   b \\
 \midrule
@@ -430,6 +435,11 @@ def test_to_latex_longtable(self):
 
         withoutindex_result = df.to_latex(index=False, longtable=True)
         withoutindex_expected = r"""\begin{longtable}{rl}
+\toprule
+ a &  b \\
+\midrule
+\endfirsthead
+
 \toprule
  a &  b \\
 \midrule
@@ -525,6 +535,9 @@ def test_to_latex_longtable_caption_label(self):
 
         df = DataFrame({"a": [1, 2], "b": ["b1", "b2"]})
 
+        # test when no caption and no label is provided
+        # is performed by test_to_latex_longtable()
+
         # test when only the caption is provided
         result_c = df.to_latex(longtable=True, caption=the_caption)
 
@@ -533,6 +546,11 @@ def test_to_latex_longtable_caption_label(self):
 \toprule
 {} &  a &   b \\
 \midrule
+\endfirsthead
+\caption[]{a table in a \texttt{longtable} environment} \\
+\toprule
+{} &  a &   b \\
+\midrule
 \endhead
 \midrule
 \multicolumn{3}{r}{{Continued on next page}} \\
@@ -552,6 +570,11 @@ def test_to_latex_longtable_caption_label(self):
 
         expected_l = r"""\begin{longtable}{lrl}
 \label{tab:longtable}\\
+\toprule
+{} &  a &   b \\
+\midrule
+\endfirsthead
+
 \toprule
 {} &  a &   b \\
 \midrule
@@ -578,6 +601,11 @@ def test_to_latex_longtable_caption_label(self):
 \toprule
 {} &  a &   b \\
 \midrule
+\endfirsthead
+\caption[]{a table in a \texttt{longtable} environment} \\
+\toprule
+{} &  a &   b \\
+\midrule
 \endhead
 \midrule
 \multicolumn{3}{r}{{Continued on next page}} \\
@@ -623,6 +651,11 @@ def test_to_latex_longtable_position(self):
         result_p = df.to_latex(longtable=True, position=the_position)
 
         expected_p = r"""\begin{longtable}[t]{lrl}
+\toprule
+{} &  a &   b \\
+\midrule
+\endfirsthead
+
 \toprule
 {} &  a &   b \\
 \midrule

From 916d8a26a699adab9b2ae1fc0d6752b1b8966bb0 Mon Sep 17 00:00:00 2001
From: jeschwar <36767735+jeschwar@users.noreply.github.com>
Date: Fri, 11 Sep 2020 15:58:55 -0600
Subject: [PATCH 2/6] BUG: fixed LongTableBuilder.middle_separator() for
 duplicate List of Tables entries (#34360)

---
 pandas/io/formats/latex.py | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/pandas/io/formats/latex.py b/pandas/io/formats/latex.py
index 8080d953da308..a8f712123eaf9 100644
--- a/pandas/io/formats/latex.py
+++ b/pandas/io/formats/latex.py
@@ -477,6 +477,11 @@ def _caption_and_label(self) -> str:
     def middle_separator(self) -> str:
         iterator = self._create_row_iterator(over="header")
         elements = [
+            "\\midrule",
+            "\\endfirsthead",
+            f"\\caption[]{{{self.caption}}} \\\\" if self.caption else "",
+            self.top_separator,
+            self.header,
             "\\midrule",
             "\\endhead",
             "\\midrule",

From 67f105dd1111e47ccaa9f3a099eb6bc423987f58 Mon Sep 17 00:00:00 2001
From: jeschwar <36767735+jeschwar@users.noreply.github.com>
Date: Fri, 11 Sep 2020 16:05:38 -0600
Subject: [PATCH 3/6] DOC: added whatsnew entry for fixing
 LongTableBuilder.middle_separator() (#34360)

---
 doc/source/whatsnew/v1.1.3.rst | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/doc/source/whatsnew/v1.1.3.rst b/doc/source/whatsnew/v1.1.3.rst
index e3161012da5d1..9e58b4bc55b7d 100644
--- a/doc/source/whatsnew/v1.1.3.rst
+++ b/doc/source/whatsnew/v1.1.3.rst
@@ -22,7 +22,7 @@ Fixed regressions
 
 Bug fixes
 ~~~~~~~~~
--
+- Fixed bug in :func:`LongTableBuilder.middle_separator` which was duplicating LaTeX longtable entires in the List of Tables of a LaTeX document (:issue:`34360`)
 
 .. ---------------------------------------------------------------------------
 

From 9539efd343329f16de165cfbe983f2e78059e153 Mon Sep 17 00:00:00 2001
From: jeschwar <36767735+jeschwar@users.noreply.github.com>
Date: Mon, 14 Sep 2020 05:52:22 -0600
Subject: [PATCH 4/6] DOC: moved whatsnew entry (#34360)

---
 doc/source/whatsnew/v1.1.3.rst | 2 +-
 doc/source/whatsnew/v1.2.0.rst | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/doc/source/whatsnew/v1.1.3.rst b/doc/source/whatsnew/v1.1.3.rst
index 9e58b4bc55b7d..e3161012da5d1 100644
--- a/doc/source/whatsnew/v1.1.3.rst
+++ b/doc/source/whatsnew/v1.1.3.rst
@@ -22,7 +22,7 @@ Fixed regressions
 
 Bug fixes
 ~~~~~~~~~
-- Fixed bug in :func:`LongTableBuilder.middle_separator` which was duplicating LaTeX longtable entires in the List of Tables of a LaTeX document (:issue:`34360`)
+-
 
 .. ---------------------------------------------------------------------------
 
diff --git a/doc/source/whatsnew/v1.2.0.rst b/doc/source/whatsnew/v1.2.0.rst
index f2f56ee81b8d4..bdd80d804ae03 100644
--- a/doc/source/whatsnew/v1.2.0.rst
+++ b/doc/source/whatsnew/v1.2.0.rst
@@ -342,7 +342,7 @@ Other
 ^^^^^
 - Bug in :meth:`DataFrame.replace` and :meth:`Series.replace` incorrectly raising ``AssertionError`` instead of ``ValueError`` when invalid parameter combinations are passed (:issue:`36045`)
 - Bug in :meth:`DataFrame.replace` and :meth:`Series.replace` with numeric values and string ``to_replace`` (:issue:`34789`)
--
+- Bug in :func:`LongTableBuilder.middle_separator` was duplicating LaTeX longtable entires in the List of Tables of a LaTeX document (:issue:`34360`)
 
 .. ---------------------------------------------------------------------------
 

From 253f31ccbec7af42ef09ab28e0e37ff16bfd85c8 Mon Sep 17 00:00:00 2001
From: jeschwar <36767735+jeschwar@users.noreply.github.com>
Date: Tue, 15 Sep 2020 18:35:36 -0600
Subject: [PATCH 5/6] DOC: added comment to LongTableBuilder.middle_separator()
 (#34360)

---
 pandas/io/formats/latex.py | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/pandas/io/formats/latex.py b/pandas/io/formats/latex.py
index a8f712123eaf9..19e6a00c6da0e 100644
--- a/pandas/io/formats/latex.py
+++ b/pandas/io/formats/latex.py
@@ -476,6 +476,10 @@ def _caption_and_label(self) -> str:
     @property
     def middle_separator(self) -> str:
         iterator = self._create_row_iterator(over="header")
+
+        # the content between \endfirsthead and \endhead commands
+        # mitigates repeated List of Tables entries in the final LaTeX
+        # document when dealing with longtable environments; GH #34360
         elements = [
             "\\midrule",
             "\\endfirsthead",

From 0e7fa0ba1b35f06d3c1aa032429abb4556277a8a Mon Sep 17 00:00:00 2001
From: jeschwar <36767735+jeschwar@users.noreply.github.com>
Date: Thu, 17 Sep 2020 05:55:58 -0600
Subject: [PATCH 6/6] TST: revised doctest for LongTableBuilder (#34360)

---
 pandas/io/formats/latex.py | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/pandas/io/formats/latex.py b/pandas/io/formats/latex.py
index 19e6a00c6da0e..eb35fff3a4f8e 100644
--- a/pandas/io/formats/latex.py
+++ b/pandas/io/formats/latex.py
@@ -431,13 +431,18 @@ class LongTableBuilder(GenericTableBuilder):
     >>> from pandas.io.formats import format as fmt
     >>> df = DataFrame({"a": [1, 2], "b": ["b1", "b2"]})
     >>> formatter = fmt.DataFrameFormatter(df)
-    >>> builder = LongTableBuilder(formatter, caption='caption', label='lab',
-    ...                            column_format='lrl')
+    >>> builder = LongTableBuilder(formatter, caption='a long table',
+    ...                            label='tab:long', column_format='lrl')
     >>> table = builder.get_result()
     >>> print(table)
     \\begin{longtable}{lrl}
-    \\caption{caption}
-    \\label{lab}\\\\
+    \\caption{a long table}
+    \\label{tab:long}\\\\
+    \\toprule
+    {} &  a &   b \\\\
+    \\midrule
+    \\endfirsthead
+    \\caption[]{a long table} \\\\
     \\toprule
     {} &  a &   b \\\\
     \\midrule