MAINT: Enforce PLW2901 (avoid loop/context var overwrite)

pypdf/_cmap.py

@@ -461,9 +461,9 @@ def build_font_width_map(
             m = 0
             cpt = 0
             for xx in w:
-                xx = xx.get_object()
-                if xx > 0:
-                    m += xx
+                xx_value = xx.get_object()
+                if xx_value > 0:
+                    m += xx_value
                     cpt += 1
             font_width_map["default"] = m / max(1, cpt)
         st = cast(int, ft["/FirstChar"])

pypdf/_doc_common.py

@@ -391,8 +391,8 @@ def recursive_call(
                     return top, -1
                 return None, mi + ma
             for idx, kid in enumerate(cast(ArrayObject, node["/Kids"])):
-                kid = cast(DictionaryObject, kid.get_object())
-                n, i = recursive_call(kid, mi)
+                kid_object = cast(DictionaryObject, kid.get_object())
+                n, i = recursive_call(kid_object, mi)
                 if n is not None:  # page has just been found ...
                     if i < 0:  # ... just below!
                         return node, idx
@@ -612,8 +612,8 @@ def _build_field(
             states: list[str] = []
             retval[key][NameObject("/_States_")] = ArrayObject(states)
             for k in obj.get(FA.Kids, {}):
-                k = k.get_object()
-                for s in list(k["/AP"]["/N"].keys()):
+                k_object = k.get_object()
+                for s in list(k_object["/AP"]["/N"].keys()):
                     if s not in states:
                         states.append(s)
                 retval[key][NameObject("/_States_")] = ArrayObject(states)
@@ -641,8 +641,8 @@ def _check_kids(
         if PagesAttributes.KIDS in tree:
             # recurse down the tree
             for kid in tree[PagesAttributes.KIDS]:  # type: ignore
-                kid = kid.get_object()
-                self.get_fields(kid, retval, fileobj, stack)
+                kid_object = kid.get_object()
+                self.get_fields(kid_object, retval, fileobj, stack)
 
     def _write_field(self, fileobj: Any, field: Any, field_attributes: Any) -> None:
         field_attributes_tuple = FA.attributes()
@@ -771,16 +771,16 @@ def _get_inherited(obj: DictionaryObject, key: str) -> Any:
         else:
             kids = field.get("/Kids", ())
             for k in kids:
-                k = k.get_object()
-                if (k.get("/Subtype", "") == "/Widget") and ("/T" not in k):
+                k_object = k.get_object()
+                if (k_object.get("/Subtype", "") == "/Widget") and ("/T" not in k_object):
                     # Kid that is just a widget, not a field:
-                    if "/P" in k:
-                        ret += [k["/P"].get_object()]
+                    if "/P" in k_object:
+                        ret += [k_object["/P"].get_object()]
                     else:
                         ret += [
                             p
                             for p in self.pages
-                            if k.indirect_reference in p.get("/Annots", "")
+                            if k_object.indirect_reference in p.get("/Annots", "")
                         ]
         return [
             x
@@ -1317,9 +1317,9 @@ def xfa(self) -> Optional[dict[str, Any]]:
             i = iter(fields)
             for f in i:
                 tag = f
-                f = next(i)
-                if isinstance(f, IndirectObject):
-                    field = cast(Optional[EncodedStreamObject], f.get_object())
+                field_value = next(i)
+                if isinstance(field_value, IndirectObject):
+                    field = cast(Optional[EncodedStreamObject], field_value.get_object())
                     if field:
                         es = zlib.decompress(field._data)
                         retval[tag] = es

pypdf/_page.py

@@ -743,14 +743,17 @@ def _get_inline_images(self) -> dict[str, ImageFile]:
                 if k in {"/Length", "/L"}:  # no length is expected
                     continue
                 if isinstance(v, list):
-                    v = ArrayObject(
-                        [self._translate_value_inline_image(k, x) for x in v]
+                    value_for_init = cast(
+                        PdfObject,
+                        ArrayObject(
+                            [self._translate_value_inline_image(k, x) for x in v]
+                        ),
                     )
                 else:
-                    v = self._translate_value_inline_image(k, v)
-                k = NameObject(_INLINE_IMAGE_KEY_MAPPING[k])
-                if k not in init:
-                    init[k] = v
+                    value_for_init = self._translate_value_inline_image(k, v)
+                mapped_k = NameObject(_INLINE_IMAGE_KEY_MAPPING[k])
+                if mapped_k not in init:
+                    init[mapped_k] = value_for_init
             ii["object"] = EncodedStreamObject.initialize_from_dictionary(init)
             extension, byte_stream, img = _xobj_to_image(ii["object"])
             files[f"~{num}~"] = ImageFile(
@@ -1236,13 +1239,13 @@ def _merge_page_writer(
             else:
                 trsf = Transformation(ctm)
             for a in cast(ArrayObject, page2[PG.ANNOTS]):
-                a = a.get_object()
-                aa = a.clone(
+                annotation_object = a.get_object()
+                aa = annotation_object.clone(
                     pdf,
                     ignore_fields=("/P", "/StructParent", "/Parent"),
                     force_duplicate=True,
                 )
-                r = cast(ArrayObject, a["/Rect"])
+                r = cast(ArrayObject, annotation_object["/Rect"])
                 pt1 = trsf.apply_on((r[0], r[1]), True)
                 pt2 = trsf.apply_on((r[2], r[3]), True)
                 aa[NameObject("/Rect")] = ArrayObject(
@@ -1253,8 +1256,8 @@ def _merge_page_writer(
                         max(pt1[1], pt2[1]),
                     )
                 )
-                if "/QuadPoints" in a:
-                    q = cast(ArrayObject, a["/QuadPoints"])
+                if "/QuadPoints" in annotation_object:
+                    q = cast(ArrayObject, annotation_object["/QuadPoints"])
                     aa[NameObject("/QuadPoints")] = ArrayObject(
                         trsf.apply_on((q[0], q[1]), True)
                         + trsf.apply_on((q[2], q[3]), True)

pypdf/_text_extraction/_layout_mode/_fixed_width_page.py

@@ -186,13 +186,14 @@ def recurs_to_target_op(
             tj_ops.append(text_state_mgr.text_state_params(operands[2]))
         elif op in (b"Td", b"Tm", b"TD", b"T*"):
             text_state_mgr.reset_trm()
+            operands_for_tm = operands
             if op == b"Tm":
                 text_state_mgr.reset_tm()
             elif op == b"TD":
                 text_state_mgr.set_state_param(b"TL", -operands[1])
             elif op == b"T*":
-                operands = [0, -text_state_mgr.TL]
-            text_state_mgr.add_tm(operands)
+                operands_for_tm = [0, -text_state_mgr.TL]
+            text_state_mgr.add_tm(operands_for_tm)
         elif op == b"Tf":
             text_state_mgr.set_font(fonts[operands[0]], operands[1])
         else:  # handle Tc, Tw, Tz, TL, and Ts operators

pypdf/_text_extraction/_layout_mode/_font.py

@@ -64,9 +64,12 @@ def __post_init__(self) -> None:
             for d_font_idx, d_font in enumerate(
                 self.font_dictionary["/DescendantFonts"]
             ):
-                while isinstance(d_font, IndirectObject):
-                    d_font = d_font.get_object()
-                self.font_dictionary["/DescendantFonts"][d_font_idx] = d_font
+                if isinstance(d_font, IndirectObject):
+                    d_font_object = d_font.get_object()
+                else:
+                    d_font_object = d_font
+                assert not isinstance(d_font_object, IndirectObject), d_font_object
+                self.font_dictionary["/DescendantFonts"][d_font_idx] = d_font_object
                 ord_map = {
                     ord(_target): _surrogate
                     for _target, _surrogate in self.char_map.items()
@@ -80,18 +83,18 @@ def __post_init__(self) -> None:
                 skip_count = 0
                 _w = d_font.get("/W", [])
                 for idx, w_entry in enumerate(_w):
-                    w_entry = w_entry.get_object()
+                    w_value = w_entry.get_object()
                     if skip_count:
                         skip_count -= 1
                         continue
-                    if not isinstance(w_entry, (int, float)):  # pragma: no cover
+                    if not isinstance(w_value, (int, float)):  # pragma: no cover
                         # We should never get here due to skip_count above. Add a
                         # warning and or use reader's "strict" to force an ex???
                         continue
                     # check for format (1): `int [int int int int ...]`
                     w_next_entry = _w[idx + 1].get_object()
                     if isinstance(w_next_entry, Sequence):
-                        start_idx, width_list = w_entry, w_next_entry
+                        start_idx, width_list = w_value, w_next_entry
                         self.width_map.update(
                             {
                                 ord_map[_cidx]: _width
@@ -112,7 +115,7 @@ def __post_init__(self) -> None:
                         _w[idx + 2].get_object(), (int, float)
                     ):
                         start_idx, stop_idx, const_width = (
-                            w_entry,
+                            w_value,
                             w_next_entry,
                             _w[idx + 2].get_object(),
                         )

pypdf/_writer.py

@@ -982,8 +982,8 @@ def update_page_form_field_values(
         if PG.ANNOTS not in page:
             logger_warning("No fields to update on this page", __name__)
             return
-        for annotation in page[PG.ANNOTS]:  # type: ignore
-            annotation = cast(DictionaryObject, annotation.get_object())
+        for annotation_ref in page[PG.ANNOTS]:  # type: ignore
+            annotation = cast(DictionaryObject, annotation_ref.get_object())
             if annotation.get("/Subtype", "") != "/Widget":
                 continue
             if "/FT" in annotation and "/T" in annotation:
@@ -1007,7 +1007,6 @@ def update_page_form_field_values(
                     del parent_annotation["/I"]
                 if flags:
                     annotation[NameObject(FA.Ff)] = NumberObject(flags)
-                # Set the field value
                 if not (value is None and flatten):  # Only change values if given by user and not flattening.
                     if isinstance(value, list):
                         lst = ArrayObject(TextStringObject(v) for v in value)
@@ -1029,9 +1028,14 @@ def update_page_form_field_values(
                     if v not in normal_ap:
                         v = NameObject("/Off")
                     appearance_stream_obj = normal_ap.get(v)
-                    # Other cases will be updated through the for loop
+                    # other cases will be updated through the for loop
                     annotation[NameObject(AA.AS)] = v
                     annotation[NameObject(FA.V)] = v
+                    if flatten and appearance_stream_obj is not None:
+                        # We basically copy the entire appearance stream, which should be an XObject that
+                        # is already registered. No need to add font resources.
+                        rct = cast(RectangleObject, annotation[AA.Rect])
+                        self._add_apstream_object(page, appearance_stream_obj, field, rct[0], rct[1])
                 elif (
                     parent_annotation.get(FA.FT) == "/Tx"
                     or parent_annotation.get(FA.FT) == "/Ch"
@@ -1050,7 +1054,7 @@ def update_page_form_field_values(
                         annotation[NameObject(AA.AP)] = DictionaryObject(
                             {NameObject("/N"): self._add_object(appearance_stream_obj)}
                         )
-                    elif "/N" not in (ap:= cast(DictionaryObject, annotation[AA.AP])):
+                    elif "/N" not in (ap := cast(DictionaryObject, annotation[AA.AP])):
                         cast(DictionaryObject, annotation[NameObject(AA.AP)])[
                             NameObject("/N")
                         ] = self._add_object(appearance_stream_obj)
@@ -1100,9 +1104,9 @@ def reattach_fields(
         if "/Annots" not in page:
             return lst
         annotations = cast(ArrayObject, page["/Annots"])
-        for idx, annotation in enumerate(annotations):
-            is_indirect = isinstance(annotation, IndirectObject)
-            annotation = cast(DictionaryObject, annotation.get_object())
+        for idx, annotation_ref in enumerate(annotations):
+            is_indirect = isinstance(annotation_ref, IndirectObject)
+            annotation = cast(DictionaryObject, annotation_ref.get_object())
             if annotation.get("/Subtype", "") == "/Widget" and "/FT" in annotation:
                 if (
                     "indirect_reference" in annotation.__dict__
@@ -1472,9 +1476,10 @@ def _write_pdf_structure(self, stream: StreamType) -> tuple[list[int], list[int]
             if obj is not None:
                 object_positions.append(stream.tell())
                 stream.write(f"{idnum} 0 obj\n".encode())
+                object_to_write = obj
                 if self._encryption and obj != self._encrypt_entry:
-                    obj = self._encryption.encrypt_object(obj, idnum, 0)
-                obj.write_to_stream(stream)
+                    object_to_write = self._encryption.encrypt_object(obj, idnum, 0)
+                object_to_write.write_to_stream(stream)
                 stream.write(b"\nendobj\n")
             else:
                 object_positions.append(-1)
@@ -1563,9 +1568,8 @@ def add_metadata(self, infos: dict[str, Any]) -> None:
         if isinstance(infos, PdfObject):
             infos = cast(DictionaryObject, infos.get_object())
         for key, value in list(infos.items()):
-            if isinstance(value, PdfObject):
-                value = value.get_object()
-            args[NameObject(key)] = create_string_object(str(value))
+            value_obj = value.get_object() if isinstance(value, PdfObject) else value
+            args[NameObject(key)] = create_string_object(str(value_obj))
         if self._info is None:
             self._info = DictionaryObject()
         self._info.update(args)

pypdf/filters.py

@@ -759,30 +759,31 @@ def decode_stream_data(stream: Any) -> bytes:
     # If there is no data to decode, we should not try to decode it.
     if not data:
         return data
-    for filter_name, params in zip(filters, decode_parms):
-        if isinstance(params, NullObject):
-            params = {}
+    for filter_name, params_untyped in zip(filters, decode_parms):
+        params_typed: Optional[DictionaryObject] = None
+        if not isinstance(params_untyped, NullObject):
+            params_typed = cast(Optional[DictionaryObject], params_untyped)
         if filter_name in (FT.ASCII_HEX_DECODE, FTA.AHx):
             data = ASCIIHexDecode.decode(data)
         elif filter_name in (FT.ASCII_85_DECODE, FTA.A85):
             data = ASCII85Decode.decode(data)
         elif filter_name in (FT.LZW_DECODE, FTA.LZW):
-            data = LZWDecode.decode(data, params)
+            data = LZWDecode.decode(data, params_typed)
         elif filter_name in (FT.FLATE_DECODE, FTA.FL):
-            data = FlateDecode.decode(data, params)
+            data = FlateDecode.decode(data, params_typed)
         elif filter_name in (FT.RUN_LENGTH_DECODE, FTA.RL):
             data = RunLengthDecode.decode(data)
         elif filter_name == FT.CCITT_FAX_DECODE:
             height = stream.get(IA.HEIGHT, ())
-            data = CCITTFaxDecode.decode(data, params, height)
+            data = CCITTFaxDecode.decode(data, params_typed, height)
         elif filter_name == FT.DCT_DECODE:
             data = DCTDecode.decode(data)
         elif filter_name == FT.JPX_DECODE:
             data = JPXDecode.decode(data)
         elif filter_name == FT.JBIG2_DECODE:
-            data = JBIG2Decode.decode(data, params)
+            data = JBIG2Decode.decode(data, params_typed)
         elif filter_name == "/Crypt":
-            if "/Name" in params or "/Type" in params:
+            if "/Name" in params_untyped or "/Type" in params_untyped:
                 raise NotImplementedError(
                     "/Crypt filter with /Name or /Type not supported yet"
                 )

pypdf/generic/_files.py

@@ -394,8 +394,8 @@ def _load(cls, catalog: DictionaryObject) -> Generator[EmbeddedFile]:
             for kid in cast(ArrayObject, container["/Kids"].get_object()):
                 # There might be further (nested) kids here.
                 # Wait for an example before evaluating an implementation.
-                kid = kid.get_object()
-                if "/Names" in kid:
-                    yield from cls._load_from_names(cast(ArrayObject, kid["/Names"]))
+                kid_object = kid.get_object()
+                if "/Names" in kid_object:
+                    yield from cls._load_from_names(cast(ArrayObject, kid_object["/Names"]))
         if "/Names" in container:
             yield from cls._load_from_names(cast(ArrayObject, container["/Names"]))

pyproject.toml

@@ -173,7 +173,6 @@ ignore = [
     "PERF203", # `try`-`except` within a loop incurs performance overhead
     "PGH003",  # Use specific rule codes when ignoring type issues
     "PLW1510", # `subprocess.run` without explicit `check` argument
-    "PLW2901", # `with` statement variable `img` overwritten by assignment target
     "PT011",   # `pytest.raises(ValueError)` is too broad, set the `match`
     "PT012",   # `pytest.raises()` block should contain a single simple statement
     "PT014",   # Ruff bug: Duplicate of test case at index 1 in `@pytest_mark.parametrize`

tests/scripts/test_make_release.py

@@ -41,8 +41,8 @@ def test_strip_header(data, expected):
 def test_get_git_commits_since_tag():
     make_release = pytest.importorskip("make_release")
 
-    with open(COMMITS__VERSION_4_0_1, mode="rb") as commits, mock.patch(
-        "urllib.request.urlopen", side_effect=lambda _: commits
+    with open(COMMITS__VERSION_4_0_1, mode="rb") as commits_fh, mock.patch(
+        "urllib.request.urlopen", side_effect=lambda _: commits_fh
     ), mock.patch("subprocess.check_output", return_value=GIT_LOG__VERSION_4_0_1):
         commits = make_release.get_git_commits_since_tag("4.0.1")
     assert commits == [
@@ -87,8 +87,8 @@ def test_get_git_commits_since_tag():
 def test_get_formatted_changes():
     make_release = pytest.importorskip("make_release")
 
-    with open(COMMITS__VERSION_4_0_1, mode="rb") as commits, mock.patch(
-        "urllib.request.urlopen", side_effect=lambda _: commits
+    with open(COMMITS__VERSION_4_0_1, mode="rb") as commits_fh, mock.patch(
+        "urllib.request.urlopen", side_effect=lambda _: commits_fh
     ), mock.patch("subprocess.check_output", return_value=GIT_LOG__VERSION_4_0_1):
         output, output_with_user = make_release.get_formatted_changes("4.0.1")
 
@@ -126,8 +126,6 @@ def test_get_formatted_changes():
 - Avoid catching not emitted warnings (#2429) by @stefan6419846
 """
     )
-
-
 def test_get_formatted_changes__other():
     make_release = pytest.importorskip("make_release")
 

tests/test_filters.py

@@ -82,9 +82,9 @@ def test_flatedecode_unsupported_predictor():
     predictors = (-10, -1, 0, 9, 16, 20, 100)
 
     for predictor, s in cartesian_product(predictors, filter_inputs):
-        s = s.encode()
+        s_bytes = s.encode()
         with pytest.raises(PdfReadError):
-            codec.decode(codec.encode(s), DictionaryObject({"/Predictor": predictor}))
+            codec.decode(codec.encode(s_bytes), DictionaryObject({"/Predictor": predictor}))
 
 
 @pytest.mark.parametrize(

tests/test_images.py

@@ -32,9 +32,9 @@ def open_image(path: Union[Path, Image.Image, BytesIO]) -> Image.Image:
     else:
         if isinstance(path, Path):
             assert path.exists()
-        with Image.open(path) as img:
+        with Image.open(path) as opened_img:
             img = (
-                img.copy()
+                opened_img.copy()
             )  # Opened image should be copied to avoid issues with file closing
     return img