BUG: Fix handling of compiled regex in Series.str.contains for Arrow-backed strings

Author: Aniketsy

pandas/core/strings/accessor.py

@@ -1,5 +1,7 @@
 from __future__ import annotations
 
+from pandas.core.dtypes.dtypes import ArrowDtype
+
 import codecs
 from functools import wraps
 import re
@@ -1338,13 +1340,6 @@ def contains(
         4    False
         dtype: bool
         """
-        from pandas.core.dtypes.dtypes import ArrowDtype
-        import re
-
-        # --- Handle Arrow-backed string arrays with compiled regex patterns ---
-        # Arrow backend does not support compiled regex objects or Python regex flags.
-        # If a compiled regex is passed, only allow it if no flags are set.
-
         if isinstance(self._data.dtype, ArrowDtype) and isinstance(pat, re.Pattern):
             if flags != 0:
                 raise NotImplementedError(
@@ -1371,7 +1366,6 @@ def contains(
                     f"Invalid regex pattern passed to str.contains(): {e}"
                 ) from e
 
-
         result = self._data.array._str_contains(pat, case, flags, na, regex)
         return self._wrap_result(result, fill_value=na, returns_string=False)