add test for single condition

pandas-dev · Oct 18, 2023 · cf6d1d1 · cf6d1d1
1 parent cff8030
commit cf6d1d1
Showing 1 changed file with 9 additions and 0 deletions.
diff --git a/pandas/tests/test_case_when.py b/pandas/tests/test_case_when.py
@@ -51,6 +51,15 @@ def test_case_when_raise_error_from_mask(df):
         case_when(df["a"].eq(1), df)
 
 
+def test_case_when_single_condition(df):
+    """
+    Test output on a single condition.
+    """
+    result = case_when(df.a.eq(1), 1)
+    expected = Series([1, np.nan, np.nan])
+    tm.assert_series_equal(result, expected)
+
+
 def test_case_when_multiple_conditions(df):
     """
     Test output when booleans are derived from a computation