Remove functools.walk() and the Jinja2 walk filter

betty/functools.py

@@ -22,38 +22,12 @@
     TYPE_CHECKING,
 )
 
-from betty.warnings import deprecated
-
 if TYPE_CHECKING:
     from collections.abc import MutableSequence
 
 _T = TypeVar("_T")
 
 
-@deprecated(
-    "This function is deprecated as of Betty 0.3.5, and will be removed in Betty 0.4.x. Instead, use a custom function, tailored to your data type."
-)
-def walk(item: Any, attribute_name: str) -> Iterable[Any]:
-    """
-    Walk over a graph of objects by following a single attribute.
-    """
-    child = getattr(item, attribute_name)
-
-    # If the child has the requested attribute, yield it,
-    if hasattr(child, attribute_name):
-        yield child
-        yield from walk(child, attribute_name)
-
-    # Otherwise loop over the children and yield their attributes.
-    try:
-        child_children = iter(child)
-    except TypeError:
-        return
-    for child_child in child_children:
-        yield child_child
-        yield from walk(child_child, attribute_name)
-
-
 def slice_to_range(indices: slice, iterable: Sized) -> Iterable[int]:
     """
     Apply a slice to an iterable, and return the corresponding range.

betty/jinja2/filter.py

@@ -35,7 +35,6 @@
 from pdf2image.pdf2image import convert_from_path
 
 from betty import _resizeimage
-from betty.functools import walk
 from betty.hashid import hashid_file_meta, hashid
 from betty.locale import (
     negotiate_localizeds,
@@ -147,13 +146,6 @@ async def filter_flatten(values_of_values: Iterable[Iterable[_T]]) -> AsyncItera
             yield value
 
 
-def filter_walk(value: Any, attribute_name: str) -> Iterable[Any]:
-    """
-    Walk over a data structure.
-    """
-    return walk(value, attribute_name)
-
-
 _paragraph_re = re.compile(r"(?:\r\n|\r|\n){2,}")
 
 
@@ -588,7 +580,6 @@ def filter_public_js(context: Context, public_path: str) -> None:
     "upper_camel_case_to_lower_camel_case": upper_camel_case_to_lower_camel_case,
     "url": filter_url,
     "void_none": void_none,
-    "walk": filter_walk,
     "public_css": filter_public_css,
     "public_js": filter_public_js,
 }

betty/tests/test_functools.py

@@ -1,74 +1,13 @@
 from collections.abc import Awaitable, Callable, Iterable
-from typing import Any, Self, TypeVar
+from typing import Any, TypeVar
 
 import pytest
 
-from betty.functools import walk, slice_to_range, Do, Uniquifier
-from betty.warnings import BettyDeprecationWarning
+from betty.functools import slice_to_range, Do, Uniquifier
 
 _T = TypeVar("_T")
 
 
-class TestWalk:
-    class _Item:
-        def __init__(self, child: Self | Iterable[Self] | None):
-            self.child = child
-
-    @pytest.mark.parametrize(
-        "item",
-        [
-            None,
-            True,
-            object(),
-            [],
-        ],
-    )
-    async def test_with_invalid_attribute(self, item: Any) -> None:
-        with pytest.warns(BettyDeprecationWarning), pytest.raises(AttributeError):
-            list(walk(item, "invalid_attribute_name"))
-
-    async def test_one_to_one_without_descendants(self) -> None:
-        with pytest.warns(BettyDeprecationWarning):
-            item = self._Item(None)
-            actual = walk(item, "child")
-            expected: list[None] = []
-            assert expected == list(actual)
-
-    async def test_one_to_one_with_descendants(self) -> None:
-        with pytest.warns(BettyDeprecationWarning):
-            grandchild = self._Item(None)
-            child = self._Item(grandchild)
-            item = self._Item(child)
-            actual = walk(item, "child")
-            expected = [child, grandchild]
-            assert expected == list(actual)
-
-    async def test_one_to_many_without_descendants(self) -> None:
-        with pytest.warns(BettyDeprecationWarning):
-            item = self._Item([])
-            actual = walk(item, "child")
-            expected: list[None] = []
-            assert expected == list(actual)
-
-    async def test_with_one_to_many_descendants(self) -> None:
-        with pytest.warns(BettyDeprecationWarning):
-            grandchild = self._Item([])
-            child = self._Item([grandchild])
-            item = self._Item([child])
-            actual = walk(item, "child")
-            expected = [child, grandchild]
-            assert expected == list(actual)
-
-    async def test_with_mixed_descendants(self) -> None:
-        with pytest.warns(BettyDeprecationWarning):
-            grandchild = self._Item([])
-            child = self._Item(grandchild)
-            item = self._Item([child])
-            actual = walk(item, "child")
-            expected = [child, grandchild]
-            assert expected == list(actual)
-
-
 class TestSliceToRange:
     @pytest.mark.parametrize(
         ("expected_range_items", "ranged_slice"),

betty/tests/test_jinja2.py

@@ -1,7 +1,7 @@
 from __future__ import annotations
 
 from pathlib import Path
-from typing import Iterable, Any, Self
+from typing import Iterable, Any
 
 import aiofiles
 import pytest
@@ -24,7 +24,6 @@
     Citation,
 )
 from betty.tests import TemplateTestCase
-from betty.warnings import BettyDeprecationWarning
 
 
 class TestJinja2Provider:
@@ -71,43 +70,6 @@ async def test(self, expected: str, template: str) -> None:
             assert expected == actual
 
 
-class TestFilterWalk(TemplateTestCase):
-    class WalkData:
-        def __init__(self, label: str, children: Iterable[Self] | None = None):
-            self._label = label
-            self.children = children or []
-
-        def __str__(self) -> str:
-            return self._label
-
-    @pytest.mark.parametrize(
-        ("expected", "template", "data"),
-        [
-            ("", '{{ data | walk("children") | join }}', WalkData("parent")),
-            (
-                "child1, child1child1, child2",
-                '{{ data | walk("children") | join(", ") }}',
-                WalkData(
-                    "parent",
-                    [
-                        WalkData("child1", [WalkData("child1child1")]),
-                        WalkData("child2"),
-                    ],
-                ),
-            ),
-        ],
-    )
-    async def test(self, expected: str, template: str, data: WalkData) -> None:
-        with pytest.warns(BettyDeprecationWarning):
-            async with self._render(
-                template_string=template,
-                data={
-                    "data": data,
-                },
-            ) as (actual, _):
-                assert expected == actual
-
-
 class TestFilterParagraphs(TemplateTestCase):
     @pytest.mark.parametrize(
         ("expected", "template"),