TST: Test groupby for columns with string objects (#52757)

pandas-dev · Apr 22, 2023 · 681af4c · 681af4c
1 parent 84f3591
commit 681af4c
Showing 1 changed file with 11 additions and 0 deletions.
diff --git a/pandas/tests/groupby/test_groupby.py b/pandas/tests/groupby/test_groupby.py
@@ -2970,3 +2970,14 @@ def test_groupby_numeric_only_std_no_result(numeric_only):
             ValueError, match="could not convert string to float: 'bar'"
         ):
             dfgb.std(numeric_only=numeric_only)
+
+
+@pytest.mark.parametrize("bug_var", [1, "a"])
+def test_groupby_sum_on_nan_should_return_nan(bug_var):
+    # GH 24196
+    df = DataFrame({"A": [bug_var, bug_var, bug_var, np.nan]})
+    dfgb = df.groupby(lambda x: x)
+    result = dfgb.sum(min_count=1)
+
+    expected_df = DataFrame([bug_var, bug_var, bug_var, np.nan], columns=["A"])
+    tm.assert_frame_equal(result, expected_df)