BUG-Pyarrow-implementation-of-str.fullmatch-matches-partial-string.-Issue-pandas-dev#56652

changed array.py: Makes Series(["abc$abc]).str.fullmatch("abc\\$") give the same result as when dtype = pyarow.string as opposed to dtype = str.

Issue reporter (Issue-pandas-dev#56652) requested change "//$" to "\$", but this resulted in DepreciationWarnng, so used "\\$" instead.

Change test_arrow.py: updated test_str_fullmatch to account for edge cases where string starts with and ends with literal $ as well as ends with the string.

Author: JackCollins91

pandas/core/arrays/arrow/array.py

@@ -2277,7 +2277,7 @@ def _str_match(
     def _str_fullmatch(
         self, pat, case: bool = True, flags: int = 0, na: Scalar | None = None
     ):
-        if not pat.endswith("$") or pat.endswith("//$"):
+        if not pat.endswith("$") or pat.endswith("\\$"):
             pat = f"{pat}$"
         return self._str_match(pat, case, flags, na)
 

pandas/tests/extension/test_arrow.py

@@ -1903,18 +1903,24 @@ def test_str_match(pat, case, na, exp):
 @pytest.mark.parametrize(
     "pat, case, na, exp",
     [
-        ["abc", False, None, [True, None]],
-        ["Abc", True, None, [False, None]],
-        ["bc", True, None, [False, None]],
-        ["ab", False, True, [True, True]],
-        ["a[a-z]{2}", False, None, [True, None]],
-        ["A[a-z]{1}", True, None, [False, None]],
+        ["abc", False, None, [True, True, False, None]],
+        ["Abc", True, None, [False, False, False, None]],
+        ["bc", True, None, [False, False, False, None]],
+        ["ab", False, None, [True, True, False, None]],
+        ["a[a-z]{2}", False, None, [True, True, False, None]],
+        ["A[a-z]{1}", True, None, [False, False, False, None]],
+        # GH Issue: #56652
+        ["abc$", False, None, [True, False, False, None]],
+        ["abc\\$", False, None, [False, True, False, None]],
+        ["Abc$", True, None, [False, False, False, None]],
+        ["Abc\\$", True, None, [False, False, False, None]],
     ],
 )
 def test_str_fullmatch(pat, case, na, exp):
-    ser = pd.Series(["abc", None], dtype=ArrowDtype(pa.string()))
+    ser = pd.Series(["abc", "abc$", "$abc", None], dtype=ArrowDtype(pa.string()))
     result = ser.str.match(pat, case=case, na=na)
     expected = pd.Series(exp, dtype=ArrowDtype(pa.bool_()))
+    print(result)
     tm.assert_series_equal(result, expected)