diff --git a/doc/source/whatsnew/v0.24.2.rst b/doc/source/whatsnew/v0.24.2.rst index b0f287cf0b9f6..63a83af79246c 100644 --- a/doc/source/whatsnew/v0.24.2.rst +++ b/doc/source/whatsnew/v0.24.2.rst @@ -23,6 +23,7 @@ Fixed Regressions - Fixed regression in :meth:`DataFrame.all` and :meth:`DataFrame.any` where ``bool_only=True`` was ignored (:issue:`25101`) - Fixed issue in ``DataFrame`` construction with passing a mixed list of mixed types could segfault. (:issue:`25075`) - Fixed regression in :meth:`DataFrame.apply` causing ``RecursionError`` when ``dict``-like classes were passed as argument. (:issue:`25196`) +- Fixed regression in :meth:`DataFrame.replace` where ``regex=True`` was only replacing patterns matching the start of the string (:issue:`25259`) .. _whatsnew_0242.enhancements: diff --git a/pandas/core/internals/managers.py b/pandas/core/internals/managers.py index 38b719db1709f..407db772d73e8 100644 --- a/pandas/core/internals/managers.py +++ b/pandas/core/internals/managers.py @@ -552,9 +552,9 @@ def comp(s, regex=False): if isna(s): return isna(values) if hasattr(s, 'asm8'): - return _compare_or_regex_match(maybe_convert_objects(values), - getattr(s, 'asm8'), regex) - return _compare_or_regex_match(values, s, regex) + return _compare_or_regex_search(maybe_convert_objects(values), + getattr(s, 'asm8'), regex) + return _compare_or_regex_search(values, s, regex) masks = [comp(s, regex) for i, s in enumerate(src_list)] @@ -1897,11 +1897,11 @@ def _consolidate(blocks): return new_blocks -def _compare_or_regex_match(a, b, regex=False): +def _compare_or_regex_search(a, b, regex=False): """ Compare two array_like inputs of the same shape or two scalar values - Calls operator.eq or re.match, depending on regex argument. If regex is + Calls operator.eq or re.search, depending on regex argument. If regex is True, perform an element-wise regex matching. Parameters @@ -1917,7 +1917,7 @@ def _compare_or_regex_match(a, b, regex=False): if not regex: op = lambda x: operator.eq(x, b) else: - op = np.vectorize(lambda x: bool(re.match(b, x)) if isinstance(x, str) + op = np.vectorize(lambda x: bool(re.search(b, x)) if isinstance(x, str) else False) is_a_array = isinstance(a, np.ndarray) diff --git a/pandas/tests/frame/test_replace.py b/pandas/tests/frame/test_replace.py index 219f7a1585fc2..127a64da38ba3 100644 --- a/pandas/tests/frame/test_replace.py +++ b/pandas/tests/frame/test_replace.py @@ -466,6 +466,13 @@ def test_regex_replace_dict_nested(self): assert_frame_equal(res3, expec) assert_frame_equal(res4, expec) + def test_regex_replace_dict_nested_non_first_character(self): + # GH 25259 + df = pd.DataFrame({'first': ['abc', 'bca', 'cab']}) + expected = pd.DataFrame({'first': ['.bc', 'bc.', 'c.b']}) + result = df.replace({'a': '.'}, regex=True) + assert_frame_equal(result, expected) + def test_regex_replace_dict_nested_gh4115(self): df = pd.DataFrame({'Type': ['Q', 'T', 'Q', 'Q', 'T'], 'tmp': 2}) expected = DataFrame({'Type': [0, 1, 0, 0, 1], 'tmp': 2})