diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 6d1f38f9a..02a02c774 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -9,7 +9,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        python: ['3.10']
+        python: ['3.12']
         os: [ubuntu-latest]
     steps:
       - uses: actions/checkout@v4
diff --git a/.github/workflows/verify.yml b/.github/workflows/verify.yml
index dd7e05a52..ccad6f271 100644
--- a/.github/workflows/verify.yml
+++ b/.github/workflows/verify.yml
@@ -7,7 +7,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        python: ['3.10']
+        python: ['3.12']
         os: [ubuntu-latest]
     steps:
       - uses: actions/checkout@v4
diff --git a/README.rst b/README.rst
index 28a5a6257..fc0fe3a66 100644
--- a/README.rst
+++ b/README.rst
@@ -44,14 +44,14 @@ The ``xls2xform`` command can then be used::
 
     xls2xform path_to_XLSForm [output_path]
 
-The currently supported Python versions for ``pyxform`` are 3.10, 3.11, 3.12, and 3.13.
+The currently supported Python versions for ``pyxform`` are 3.10 to 3.13 (the primary development version is 3.12). If this is different from the version you use for other projects, consider using `pyenv <https://github.com/pyenv/pyenv>`_ to manage multiple versions of Python.
 
 Running pyxform from local source
 ---------------------------------
 
 Note that you must uninstall any globally installed ``pyxform`` instance in order to use local modules. Please install java 8 or newer version.
 
-From the command line, complete the following. These steps use a `virtualenv <https://docs.python.org/3.10/tutorial/venv.html>`_ to make dependency management easier, and to keep the global site-packages directory clean::
+From the command line, complete the following. These steps use a virtualenv to make dependency management easier, and to keep the global site-packages directory clean::
 
     # Get a copy of the repository.
     mkdir -P ~/repos/pyxform
@@ -59,7 +59,7 @@ From the command line, complete the following. These steps use a `virtualenv <ht
     git clone https://github.com/XLSForm/pyxform.git repo
 
     # Create and activate a virtual environment for the install.
-    /usr/local/bin/python3.10 -m venv venv
+    /usr/local/bin/python -m venv venv
     . venv/bin/activate
 
     # Install the pyxform and it's production dependencies.
@@ -154,7 +154,7 @@ Releases are now automatic. These instructions are provided for forks or for a f
 1. In a clean new release only directory, check out master.
 2. Create a new virtualenv in this directory to ensure a clean Python environment::
 
-     /usr/local/bin/python3.10 -m venv pyxform-release
+     /usr/local/bin/python -m venv pyxform-release
      . pyxform-release/bin/activate
 
 3. Install the production and packaging requirements::
diff --git a/pyproject.toml b/pyproject.toml
index c95c9cad7..5b954030c 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -9,7 +9,7 @@ readme = "README.rst"
 requires-python = ">=3.10"
 dependencies = [
   "xlrd==2.0.1",        # Read XLS files
-  "openpyxl==3.1.3",    # Read XLSX files
+  "openpyxl==3.1.5",    # Read XLSX files
   "defusedxml==0.7.1",  # Parse XML
 ]
 
@@ -17,9 +17,9 @@ dependencies = [
 # Install with `pip install pyxform[dev]`.
 dev = [
   "formencode==2.1.1",  # Compare XML
-  "lxml==5.3.0",        # XPath test expressions
-  "psutil==6.1.0",      # Process info for performance tests
-  "ruff==0.7.1",        # Format and lint
+  "lxml==6.0.0",        # XPath test expressions
+  "psutil==7.0.0",      # Process info for performance tests
+  "ruff==0.12.4",        # Format and lint
 ]
 
 [project.urls]
@@ -75,6 +75,7 @@ ignore = [
   "F821",  # undefined-name (doesn't work well with type hints, ruff 0.1.11).
   "PERF401",  # manual-list-comprehension (false positives on selective transforms)
   "PERF402",  # manual-list-copy (false positives on selective transforms)
+  "PLC0415",  # import-outside-top-level (pyxform has a few to avoid circular imports)
   "PLR0911",  # too-many-return-statements (complexity not useful to warn every time)
   "PLR0912",  # too-many-branches (complexity not useful to warn every time)
   "PLR0913",  # too-many-arguments (complexity not useful to warn every time)
@@ -83,7 +84,6 @@ ignore = [
   "PLW2901",  # redefined-loop-name (usually not a bug)
   "RUF001",  # ambiguous-unicode-character-string (false positives on unicode tests)
   "S310",  # suspicious-url-open-usage (prone to false positives, ruff 0.1.11)
-  "S320",  # suspicious-xmle-tree-usage (according to defusedxml author lxml is safe)
   "S603",  # subprocess-without-shell-equals-true (prone to false positives, ruff 0.1.11)
   "TRY003",  # raise-vanilla-args (reasonable lint but would require large refactor)
 ]
diff --git a/pyxform/builder.py b/pyxform/builder.py
index 2b699de96..1d3efd063 100644
--- a/pyxform/builder.py
+++ b/pyxform/builder.py
@@ -335,9 +335,7 @@ def create_survey(
 
     # assert name_of_main_section in sections, name_of_main_section
     if "id_string" not in main_section:
-        main_section["id_string"] = (
-            name_of_main_section if id_string is None else name_of_main_section
-        )
+        main_section["id_string"] = name_of_main_section
     survey = builder.create_survey_element_from_dict(main_section)
 
     # not sure where to do this without repeating ourselves,
diff --git a/pyxform/instance.py b/pyxform/instance.py
index ae47fedbf..eb36f4de9 100644
--- a/pyxform/instance.py
+++ b/pyxform/instance.py
@@ -90,8 +90,4 @@ def __unicode__(self):
         orphan_count = len(self._orphan_answers.keys())
         placed_count = len(self._answers.keys())
         answer_count = orphan_count + placed_count
-        return "<Instance (%d answers: %d placed. %d orphans)>" % (
-            answer_count,
-            placed_count,
-            orphan_count,
-        )
+        return f"<Instance ({answer_count} answers: {placed_count} placed. {orphan_count} orphans)>"
diff --git a/pyxform/parsing/expression.py b/pyxform/parsing/expression.py
index d94c0c940..972cff33a 100644
--- a/pyxform/parsing/expression.py
+++ b/pyxform/parsing/expression.py
@@ -77,7 +77,7 @@ def tokenizer(scan, value) -> ExpLexerToken | str:
 
 
 class ExpLexerToken:
-    __slots__ = ("name", "value", "start", "end")
+    __slots__ = ("end", "name", "start", "value")
 
     def __init__(self, name: str, value: str, start: int, end: int) -> None:
         self.name: str = name
diff --git a/pyxform/parsing/sheet_headers.py b/pyxform/parsing/sheet_headers.py
index 9c69e2421..7337e5da8 100644
--- a/pyxform/parsing/sheet_headers.py
+++ b/pyxform/parsing/sheet_headers.py
@@ -50,7 +50,7 @@ def merge_dicts(
     # Union keys but retain order (as opposed to set()), preferencing dict_a then dict_b.
     # E.g. {"a": 1, "b": 2} + {"c": 3, "a": 4} -> {"a": None, "b": None, "c": None}
     out_dict = dict_a
-    for key in {k: None for k in (chain(dict_a, dict_b))}:
+    for key in dict.fromkeys(chain(dict_a, dict_b)):
         out_dict[key] = merge_dicts(dict_a.get(key), dict_b.get(key), default_key)
     return out_dict
 
@@ -66,7 +66,7 @@ def list_to_nested_dict(lst: Sequence) -> dict:
 
 
 class DealiasAndGroupHeadersResult:
-    __slots__ = ("headers", "data")
+    __slots__ = ("data", "headers")
 
     def __init__(self, headers: tuple[tuple[str, ...], ...], data: Sequence[dict]):
         """
diff --git a/pyxform/question.py b/pyxform/question.py
index 7e3442da5..bf4850804 100644
--- a/pyxform/question.py
+++ b/pyxform/question.py
@@ -146,7 +146,7 @@ def xml_instance(self, survey: "Survey", **kwargs):
 
     def xml_control(self, survey: "Survey"):
         if self.type == "calculate" or (
-            (self.bind is not None and "calculate" in self.bind or self.trigger)
+            ((self.bind is not None and "calculate" in self.bind) or self.trigger)
             and not (self.label or self.hint)
         ):
             nested_setvalues = survey.get_trigger_values_for_question_name(
diff --git a/pyxform/survey.py b/pyxform/survey.py
index bad9b2a2e..07d5e6321 100644
--- a/pyxform/survey.py
+++ b/pyxform/survey.py
@@ -48,7 +48,7 @@
 class InstanceInfo:
     """Standardise Instance details relevant during XML generation."""
 
-    __slots__ = ("type", "context", "name", "src", "instance")
+    __slots__ = ("context", "instance", "name", "src", "type")
 
     def __init__(
         self,
diff --git a/pyxform/survey_element.py b/pyxform/survey_element.py
index 242681f4d..4b1e6c455 100644
--- a/pyxform/survey_element.py
+++ b/pyxform/survey_element.py
@@ -276,7 +276,7 @@ def condition(e):
                 reversed(tuple(i[0] for i in self.iter_ancestors(condition=condition))),
                 self_element,
             )
-            new_value = f'/{"/".join(n.name for n in lineage)}'
+            new_value = f"/{'/'.join(n.name for n in lineage)}"
             self._survey_element_xpath = new_value
             return new_value
         return current_value
@@ -287,8 +287,7 @@ def _delete_keys_from_dict(self, dictionary: dict, keys: Iterable[str]):
         Credits: https://stackoverflow.com/a/49723101
         """
         for key in keys:
-            if key in dictionary:
-                del dictionary[key]
+            dictionary.pop(key, None)
 
         for value in dictionary.values():
             if isinstance(value, dict):
diff --git a/pyxform/validators/updater.py b/pyxform/validators/updater.py
index bd5df1b32..66b2a964d 100644
--- a/pyxform/validators/updater.py
+++ b/pyxform/validators/updater.py
@@ -87,7 +87,7 @@ def _request_latest_json(url):
     @staticmethod
     def _check_path(file_path):
         if not os.path.exists(file_path):
-            raise PyXFormError(f"Expected path does not exist: {file_path}" "")
+            raise PyXFormError(f"Expected path does not exist: {file_path}")
         else:
             return True
 
@@ -463,7 +463,7 @@ def check(update_info):
         :type update_info: _UpdateInfo
         """
         if not os.path.exists(update_info.installed_path):
-            message = "\nCheck failed!\n\n" "No installed release found."
+            message = "\nCheck failed!\n\nNo installed release found."
             raise PyXFormError(message)
 
         installed = _UpdateHandler._read_json(file_path=update_info.installed_path)
@@ -512,8 +512,7 @@ def _install_check(bin_file_path=None):
 class EnketoValidateUpdater(_UpdateService):
     def __init__(self):
         self.update_info = _UpdateInfo(
-            api_url="https://api.github.com/repos/enketo/enketo-validate/"
-            "releases/latest",
+            api_url="https://api.github.com/repos/enketo/enketo-validate/releases/latest",
             repo_url="https://github.com/enketo/enketo-validate",
             validate_subfolder="enketo_validate",
             install_check=self._install_check,
diff --git a/pyxform/validators/util.py b/pyxform/validators/util.py
index 835150da2..6798dcc8b 100644
--- a/pyxform/validators/util.py
+++ b/pyxform/validators/util.py
@@ -125,7 +125,7 @@ def request_get(url):
         ) from http_err
     except URLError as url_err:
         raise PyXFormError(
-            f"Unable to reach a server. Reason: {url_err.reason}. " f"URL: {url}"
+            f"Unable to reach a server. Reason: {url_err.reason}. URL: {url}"
         ) from url_err
 
 
diff --git a/pyxform/xls2json.py b/pyxform/xls2json.py
index 93ab1c386..335ad049a 100644
--- a/pyxform/xls2json.py
+++ b/pyxform/xls2json.py
@@ -1067,15 +1067,15 @@ def workbook_to_json(
                                     constants.NAME: constants.OR_OTHER_CHOICE[
                                         constants.NAME
                                     ],
-                                    constants.LABEL: {
-                                        lang: constants.OR_OTHER_CHOICE[constants.LABEL]
-                                        for lang in {
+                                    constants.LABEL: dict.fromkeys(
+                                        {
                                             lang
                                             for c in itemset_choices
                                             for lang in c[constants.LABEL]
                                             if isinstance(c.get(constants.LABEL), dict)
-                                        }
-                                    },
+                                        },
+                                        constants.OR_OTHER_CHOICE[constants.LABEL],
+                                    ),
                                 }
                             )
                         else:
diff --git a/tests/pyxform_test_case.py b/tests/pyxform_test_case.py
index b3eb785f6..7d0cfbd17 100644
--- a/tests/pyxform_test_case.py
+++ b/tests/pyxform_test_case.py
@@ -347,8 +347,7 @@ def assertContains(self, content, text, count=None, msg_prefix=""):
             self.assertEqual(
                 real_count,
                 count,
-                msg_prefix + "Found %d instances of %s in content"
-                " (expected %d)" % (real_count, text_repr, count),
+                f"{msg_prefix}Found {real_count} instances of {text_repr} in content (expected {count})",
             )
         else:
             self.assertTrue(
diff --git a/tests/test_external_instances_for_selects.py b/tests/test_external_instances_for_selects.py
index 619fd61d6..f66cdc488 100644
--- a/tests/test_external_instances_for_selects.py
+++ b/tests/test_external_instances_for_selects.py
@@ -10,6 +10,7 @@
 from pyxform import aliases
 from pyxform.constants import EXTERNAL_INSTANCE_EXTENSIONS
 from pyxform.errors import PyXFormError
+from pyxform.validators.pyxform import select_from_file
 from pyxform.xls2json_backends import md_table_to_workbook
 from pyxform.xls2xform import get_xml_path, xls2xform_convert
 
@@ -204,8 +205,6 @@ def test_param_value_and_label_validation(self):
         |        | type          | name    | label   | parameters |
         |        | {q} cities{e} | city    | City    | {p}        |
         """
-        from pyxform.validators.pyxform import select_from_file
-
         q_types = ("select_one_from_file", "select_multiple_from_file")
         good_params = (
             "value=val",
diff --git a/tests/test_sheet_columns.py b/tests/test_sheet_columns.py
index 18ff4b9f5..980238539 100644
--- a/tests/test_sheet_columns.py
+++ b/tests/test_sheet_columns.py
@@ -718,7 +718,7 @@ def test_dealias_and_group_headers__use_double_colon_modes(self):
                 observed = dealias_and_group_headers(
                     sheet_name="test",
                     sheet_data=case[0],
-                    sheet_header=[{k: None for k in case[0][0]}],
+                    sheet_header=[dict.fromkeys(case[0][0])],
                     header_aliases={},
                     header_columns=set(),
                 )
diff --git a/tests/test_xls2xform.py b/tests/test_xls2xform.py
index 1cfc4ee9b..aa725a363 100644
--- a/tests/test_xls2xform.py
+++ b/tests/test_xls2xform.py
@@ -24,7 +24,7 @@
 )
 
 from tests import example_xls
-from tests.utils import get_temp_file, path_to_text_fixture
+from tests.utils import get_temp_dir, get_temp_file, path_to_text_fixture
 
 
 class XLS2XFormTests(TestCase):
@@ -347,7 +347,6 @@ def test_args_combinations__ok(self):
     def test_invalid_input_raises(self):
         """Should raise an error for invalid input or file types."""
         msg = "Argument 'definition' was not recognized as a supported type"
-        from tests.utils import get_temp_dir, get_temp_file
 
         with get_temp_file() as empty, get_temp_dir() as td:
             bad_xls = Path(td) / "bad.xls"