From d216bacb0de01aa41160e44c52dc4c766a51e5c3 Mon Sep 17 00:00:00 2001
From: Samuel Johnson <sfjohnson24@gmail.com>
Date: Mon, 16 Feb 2026 17:09:59 -0500
Subject: [PATCH 1/2] fix

---
 cdisc_rules_engine/check_operators/dataframe_operators.py | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/cdisc_rules_engine/check_operators/dataframe_operators.py b/cdisc_rules_engine/check_operators/dataframe_operators.py
index 1cf37ede4..8effa8d62 100644
--- a/cdisc_rules_engine/check_operators/dataframe_operators.py
+++ b/cdisc_rules_engine/check_operators/dataframe_operators.py
@@ -857,7 +857,9 @@ def equals_string_part(self, other_value):
         parsed_id = str(uuid4())
         self.value[parsed_id] = parsed_data
         return self.value.apply(
-            lambda row: self._check_equality(row, target, parsed_id, value_is_literal),
+            lambda row: self._check_equality(
+                row, target, parsed_id, value_is_literal=False
+            ),
             axis=1,
         )
 

From 6ef294e158f47c5fa6237bd512f3b8abf713e1d4 Mon Sep 17 00:00:00 2001
From: Samuel Johnson <sfjohnson24@gmail.com>
Date: Mon, 16 Feb 2026 17:14:01 -0500
Subject: [PATCH 2/2] test

---
 .../test_string_comparison.py                 | 53 +++++++++++++++++++
 1 file changed, 53 insertions(+)

diff --git a/tests/unit/test_check_operators/test_string_comparison.py b/tests/unit/test_check_operators/test_string_comparison.py
index ce1de5c96..1ec3277d3 100644
--- a/tests/unit/test_check_operators/test_string_comparison.py
+++ b/tests/unit/test_check_operators/test_string_comparison.py
@@ -33,6 +33,59 @@ def test_equals_string_part(data, comparator, regex, dataset_type, expected_resu
     assert result.equals(df.convert_to_series(expected_result))
 
 
+@pytest.mark.parametrize(
+    "data,comparator,regex,dataset_type,value_is_literal,expected_result",
+    [
+        (
+            {"VAR2": ["blaAtt", "yyyBtt", "aaaCtt"], "target": ["A", "B", "D"]},
+            "VAR2",
+            ".{3}(.).*",
+            PandasDataset,
+            False,
+            [True, True, False],
+        ),
+        (
+            {"VAR2": ["blaAtt", "yyyBtt", "aaaCtt"], "target": ["A", "B", "D"]},
+            "VAR2",
+            ".{3}(.).*",
+            DaskDataset,
+            False,
+            [True, True, False],
+        ),
+        (
+            {"target": ["A", "B", "C"]},
+            "blaAtt",
+            ".{3}(.).*",
+            PandasDataset,
+            True,
+            [True, False, False],
+        ),
+        (
+            {"target": ["A", "B", "C"]},
+            "blaAtt",
+            ".{3}(.).*",
+            DaskDataset,
+            True,
+            [True, False, False],
+        ),
+    ],
+)
+def test_equals_string_part_literal(
+    data, comparator, regex, dataset_type, value_is_literal, expected_result
+):
+    df = dataset_type.from_dict(data)
+    dataframe_type = DataframeType({"value": df})
+    result = dataframe_type.equals_string_part(
+        {
+            "target": "target",
+            "comparator": comparator,
+            "regex": regex,
+            "value_is_literal": value_is_literal,
+        }
+    )
+    assert result.equals(df.convert_to_series(expected_result))
+
+
 @pytest.mark.parametrize(
     "data,comparator,dataset_type,expected_result",
     [