diff --git a/codeflash/code_utils/code_replacer.py b/codeflash/code_utils/code_replacer.py
index 269dd4706..28e252c47 100644
--- a/codeflash/code_utils/code_replacer.py
+++ b/codeflash/code_utils/code_replacer.py
@@ -354,21 +354,23 @@ def transform_asserts(self, code: str) -> str:
         return "\n".join(result_lines)
 
     def _transform_assert_line(self, line: str) -> Optional[str]:
-        indent = line[: len(line) - len(line.lstrip())]
+        indent_len = len(line) - len(line.lstrip())
+        indent = line[:indent_len]
 
-        assert_match = re.match(r"\s*assert\s+(.*?)(?:\s*==\s*.*)?$", line)
+        assert_match = self.assert_pattern.match(line)
         if assert_match:
             expression = assert_match.group(1).strip()
             if expression.startswith("not "):
                 return f"{indent}{expression}"
 
-            expression = re.sub(r"[,;]\s*$", "", expression)
+            # Removing trailing commas or semicolons without using regex
+            if expression and expression[-1] in ",;":
+                expression = expression[:-1]
             return f"{indent}{expression}"
 
-        unittest_match = re.match(r"(\s*)self\.assert([A-Za-z]+)\((.*)\)$", line)
+        unittest_match = self.unittest_pattern.match(line)
         if unittest_match:
             indent, assert_method, args = unittest_match.groups()
-
             if args:
                 arg_parts = self._split_top_level_args(args)
                 if arg_parts and arg_parts[0]:
@@ -399,6 +401,10 @@ def _split_top_level_args(self, args_str: str) -> list[str]:
 
         return result
 
+    def __init__(self):
+        self.assert_pattern = re.compile(r"\s*assert\s+(.*?)(?:\s*==\s*.*)?$")
+        self.unittest_pattern = re.compile(r"(\s*)self\.assert([A-Za-z]+)\((.*)\)$")
+
 
 def clean_concolic_tests(test_suite_code: str) -> str:
     try: