From 5c348ed4f290822c1be985f2c3ae8262131814ec Mon Sep 17 00:00:00 2001
From: Simon Hawkins <simonjayhawkins@gmail.com>
Date: Thu, 7 Mar 2019 12:54:41 +0000
Subject: [PATCH] TST: add test for groupby on list of empty list
---
pandas/tests/groupby/test_groupby.py | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/pandas/tests/groupby/test_groupby.py b/pandas/tests/groupby/test_groupby.py
index 6a11f0ae9b44a..c062fb90ca43b 100644
--- a/pandas/tests/groupby/test_groupby.py
+++ b/pandas/tests/groupby/test_groupby.py
@@ -1714,3 +1714,12 @@ def test_groupby_multiindex_nat():
result = ser.groupby(level=1).mean()
expected = pd.Series([3., 2.5], index=["a", "b"])
assert_series_equal(result, expected)
+
+
+def test_groupby_empty_list_raises():
+ # GH 5289
+ values = zip(range(10), range(10))
+ df = DataFrame(values, columns=['apple', 'b'])
+ msg = "Grouper and axis must be same length"
+ with pytest.raises(ValueError, match=msg):
+ df.groupby([[]])