From 677a27d9bdcfcc3033d2bdb0446852505bbafa64 Mon Sep 17 00:00:00 2001
From: gfyoung <gfyoung17@gmail.com>
Date: Thu, 7 Dec 2017 21:23:52 -0800
Subject: [PATCH] MAINT: Address reviewer comments

* Move whatsnew to 0.21.1.txt
* Empty tests for empty DataFrame in to_latex
---
 doc/source/whatsnew/v0.21.0.txt          |  1 -
 doc/source/whatsnew/v0.21.1.txt          |  1 +
 pandas/tests/io/formats/test_to_latex.py | 23 +++++++++++++++++++++++
 3 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/doc/source/whatsnew/v0.21.0.txt b/doc/source/whatsnew/v0.21.0.txt
index bbb4887f55e179..89e2d3006696c5 100644
--- a/doc/source/whatsnew/v0.21.0.txt
+++ b/doc/source/whatsnew/v0.21.0.txt
@@ -1089,7 +1089,6 @@ I/O
 - Bug in :meth:`DataFrame.to_html` in which there was no validation of the ``justify`` parameter (:issue:`17527`)
 - Bug in :func:`HDFStore.select` when reading a contiguous mixed-data table featuring VLArray (:issue:`17021`)
 - Bug in :func:`to_json` where several conditions (including objects with unprintable symbols, objects with deep recursion, overlong labels) caused segfaults instead of raising the appropriate exception (:issue:`14256`)
-- Bug in :meth:`DataFrame.to_latex` with ``longtable=True`` where a latex multicolumn always spanned over three columns (:issue:`17959`)
 
 Plotting
 ^^^^^^^^
diff --git a/doc/source/whatsnew/v0.21.1.txt b/doc/source/whatsnew/v0.21.1.txt
index fbfbb403b2a17a..ffeff4b59134ce 100644
--- a/doc/source/whatsnew/v0.21.1.txt
+++ b/doc/source/whatsnew/v0.21.1.txt
@@ -127,6 +127,7 @@ I/O
 - Bug in :func:`pandas.io.json.json_normalize` to avoid modification of ``meta`` (:issue:`18610`)
 - Bug in :func:`to_latex` where repeated multi-index values were not printed even though a higher level index differed from the previous row (:issue:`14484`)
 - Bug when reading NaN-only categorical columns in :class:`HDFStore` (:issue:`18413`)
+- Bug in :meth:`DataFrame.to_latex` with ``longtable=True`` where a latex multicolumn always spanned over three columns (:issue:`17959`)
 
 Plotting
 ^^^^^^^^
diff --git a/pandas/tests/io/formats/test_to_latex.py b/pandas/tests/io/formats/test_to_latex.py
index efc9a676c01b3f..039bd6e43b8820 100644
--- a/pandas/tests/io/formats/test_to_latex.py
+++ b/pandas/tests/io/formats/test_to_latex.py
@@ -91,6 +91,29 @@ def test_to_latex_format(self, frame):
 
         assert withindex_result == withindex_expected
 
+    def test_to_latex_empty(self):
+        df = DataFrame()
+        result = df.to_latex()
+        expected = r"""\begin{tabular}{l}
+\toprule
+Empty DataFrame
+Columns: Index([], dtype='object')
+Index: Index([], dtype='object') \\
+\bottomrule
+\end{tabular}
+"""
+        assert result == expected
+
+        result = df.to_latex(longtable=True)
+        expected = r"""\begin{longtable}{l}
+\toprule
+Empty DataFrame
+Columns: Index([], dtype='object')
+Index: Index([], dtype='object') \\
+\end{longtable}
+"""
+        assert result == expected
+
     def test_to_latex_with_formatters(self):
         df = DataFrame({'int': [1, 2, 3],
                         'float': [1.0, 2.0, 3.0],