diff --git a/src/jcloud_docsgen/__main__.py b/src/jcloud_docsgen/__main__.py
index 57403ce..7de7226 100644
--- a/src/jcloud_docsgen/__main__.py
+++ b/src/jcloud_docsgen/__main__.py
@@ -13,6 +13,7 @@
 # limitations under the License.
 
 import sys
+
 from .cli.cli import main
 
 if __name__ == '__main__':
diff --git a/src/jcloud_docsgen/cli/__init__.py b/src/jcloud_docsgen/cli/__init__.py
index f1ada26..0008773 100644
--- a/src/jcloud_docsgen/cli/__init__.py
+++ b/src/jcloud_docsgen/cli/__init__.py
@@ -12,8 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from . import cli
-from . import languages
+from . import cli, languages
 from .cli import main
 
 __all__ = [
diff --git a/src/jcloud_docsgen/cli/cli.py b/src/jcloud_docsgen/cli/cli.py
index 1ebdce9..ae22588 100644
--- a/src/jcloud_docsgen/cli/cli.py
+++ b/src/jcloud_docsgen/cli/cli.py
@@ -19,6 +19,7 @@ The command line interface
 import argparse
 import pathlib
 import sys
+
 from .languages.python import VALID_SECTIONS as VALID_PYTHON_SECTIONS
 
 __all__ = [
@@ -169,7 +170,7 @@ def main(argv=None) -> int:
     except SyntaxError:
         # TODO: add a custom exception class to clearify that a project
         # parsing syntax error is meant.
-        return error(f'syntax error in project source code')
+        return error('syntax error in project source code')
     except KeyboardInterrupt:
         return 130
     except BrokenPipeError:
diff --git a/src/jcloud_docsgen/cli/languages/python.py b/src/jcloud_docsgen/cli/languages/python.py
index df0dff6..ae74fe9 100644
--- a/src/jcloud_docsgen/cli/languages/python.py
+++ b/src/jcloud_docsgen/cli/languages/python.py
@@ -13,11 +13,11 @@
 # limitations under the License.
 
 import pathlib
+
 from ...core.python import (
     PythonDefinitionDocumentationIncludeSections,
     PythonDocumentationGenerator,
 )
-from typing import Optional
 
 __all__ = [
     'VALID_SECTIONS',
@@ -31,7 +31,7 @@ VALID_SECTIONS = list(
 
 
 def parse_sections_list(
-    include_sections: Optional[list[str]] = None,
+    include_sections: list[str] | None = None,
     exclude_sections: list[str] = [],
 ) -> PythonDefinitionDocumentationIncludeSections:
     """
@@ -41,7 +41,7 @@ def parse_sections_list(
     the section name.
 
     :param include_sections: The list of sections to be included.
-    :type include_sections: Optional[list[str]]
+    :type include_sections: list[str] | None
     :param exclude_sections: The list of sections to be excluded.
     :type exclude_sections: list[str]
 
@@ -110,7 +110,7 @@ def generate(
     project_directory: pathlib.Path,
     output_directory: pathlib.Path,
     *,
-    include_sections: Optional[list[str]] = None,
+    include_sections: list[str] | None = None,
     exclude_sections: list[str] = [],
     allow_html: bool = False,
     allow_tables: bool = False,
@@ -124,7 +124,7 @@ def generate(
     :type output_directory: pathlib.Path
     :param include_sections: The sections to be included in the
                              documentation.
-    :type include_sections: Optional[list[str]]
+    :type include_sections: list[str] | None
     :param exclude_sections: The sections to be excluded in the
                              documentation.
     :type exclude_sections: list[str]
diff --git a/src/jcloud_docsgen/core/python/__init__.py b/src/jcloud_docsgen/core/python/__init__.py
index 89ef350..1213677 100644
--- a/src/jcloud_docsgen/core/python/__init__.py
+++ b/src/jcloud_docsgen/core/python/__init__.py
@@ -12,9 +12,9 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+from . import namespaces
 from ._core import *
 from ._core import __all__ as _core__all__
-from . import namespaces
 
 __all__ = [
     *_core__all__,
diff --git a/src/jcloud_docsgen/core/python/_core.py b/src/jcloud_docsgen/core/python/_core.py
index 5fe9d1b..b948125 100644
--- a/src/jcloud_docsgen/core/python/_core.py
+++ b/src/jcloud_docsgen/core/python/_core.py
@@ -13,25 +13,26 @@
 # limitations under the License.
 
 from __future__ import annotations
-from ...utils import non_empty_str, get_relative_path_segments
-from ...exceptions import PythonArgumentStructureError, InvalidNamespaceError
-from .namespaces import PythonModuleNamespace, PythonPackageNamespace
+
+import ast
+import pathlib
+from collections.abc import Iterator
+from dataclasses import dataclass
+from typing import TypeAlias
+
+import docstring_parser
+
+from ...exceptions import InvalidNamespaceError, PythonArgumentStructureError
+from ...utils import get_relative_path_segments, non_empty_str
+from .arguments import PythonArgumentKind, PythonFunctionArgument
 from .definitions import (
     PythonAsyncFunctionDefinition,
     PythonClassDefinition,
     PythonDefinition,
     PythonFunctionDefinition,
 )
-from .arguments import PythonArgumentKind, PythonFunctionArgument
 from .docstrings import PythonDocstring
-from collections.abc import Iterator
-from typing import TypeAlias, Union
-from dataclasses import dataclass
-from enum import Enum
-import docstring_parser
-import pathlib
-import ast
-import types
+from .namespaces import PythonModuleNamespace, PythonPackageNamespace
 
 __all__ = [
     'PythonDefinitionDocumentationIncludeSections',
@@ -63,9 +64,9 @@ def _collect_definitions(tree_or_node) -> Iterator[PythonDefinition]:
 _Arguments: TypeAlias = tuple[
     list[PythonFunctionArgument],
     list[PythonFunctionArgument],
-    Union[PythonFunctionArgument, None],
+    PythonFunctionArgument | None,
     list[PythonFunctionArgument],
-    Union[PythonFunctionArgument, None],
+    PythonFunctionArgument | None,
 ]
 
 
@@ -298,12 +299,12 @@ def _markdown_table(
     return table.strip()
 
 
-def _is_docstring(docstring: Union[str, PythonDocstring, None]) -> bool:
+def _is_docstring(docstring: str | PythonDocstring | None) -> bool:
     """
     Checks whether the docstring is a docstring or an empty docstring.
 
     :param docstring: The docstring.
-    :type docstring: Union[str, PythonDocstring, None]
+    :type docstring: str | PythonDocstring | None
 
     :return: Whether there is a docstring.
     :rtype: bool
@@ -320,8 +321,8 @@ def _is_docstring(docstring: Union[str, PythonDocstring, None]) -> bool:
 
 @dataclass
 class _FunctionParamInfo:
-    annotation: Union[str, None]
-    description: Union[str, None]
+    annotation: str | None
+    description: str | None
 
 
 @dataclass
@@ -908,7 +909,7 @@ class PythonModuleDocumentationGenerator:
     :param src_directory: The directory of the source code. It is
                           optional and only used for making the module
                           identifiers in the documentation relative.
-    :type src_directory: Union[pathlib.Path, None]
+    :type src_directory: pathlib.Path | None
     :param include_sections: The sections that will be included.
     :type include_sections: PythonDefinitionDocumentationIncludeSections
     :param kwargs: The options for ``PythonDefinitionDocumentationGenerator``.
@@ -917,7 +918,7 @@ class PythonModuleDocumentationGenerator:
     def __init__(
         self,
         module_path: pathlib.Path,
-        src_directory: Union[pathlib.Path, None] = None,
+        src_directory: pathlib.Path | None = None,
         include_sections: PythonDefinitionDocumentationIncludeSections = (
             PythonDefinitionDocumentationIncludeSections()
         ),
diff --git a/src/jcloud_docsgen/core/python/arguments.py b/src/jcloud_docsgen/core/python/arguments.py
index 961b5dc..d993675 100644
--- a/src/jcloud_docsgen/core/python/arguments.py
+++ b/src/jcloud_docsgen/core/python/arguments.py
@@ -13,17 +13,18 @@
 # limitations under the License.
 
 from __future__ import annotations
-from enum import Enum
-from typing import Union
+
 import ast
-from ...utils import assert_that_is_instance
+import keyword
+import types
+from enum import Enum
+
 from ...exceptions import (
     InvalidPythonAnnotationError,
     InvalidPythonIdentifierError,
     PythonArgumentStructureError,
 )
-import keyword
-import types
+from ...utils import assert_that_is_instance
 
 __all__ = [
     'PythonArgumentKind',
@@ -49,17 +50,17 @@ class PythonFunctionArgument:
     :param kind: The kind of the argument.
     :type kind: ArgumentKind
     :param default: The default value of the argument.
-    :type default: Union[str, None]
+    :type default: str | None
     :param annotation: The type annotation of the argument.
-    :type annotation: Union[str, None]
+    :type annotation: str | None
     """
 
     def __init__(
         self,
         name: str,
         kind: PythonArgumentKind,
-        default: Union[str, None],
-        annotation: Union[str, None],
+        default: str | None,
+        annotation: str | None,
     ) -> None:
         assert_that_is_instance(name, str)
         assert_that_is_instance(kind, PythonArgumentKind)
diff --git a/src/jcloud_docsgen/core/python/definitions.py b/src/jcloud_docsgen/core/python/definitions.py
index 7c9ac1d..923b80a 100644
--- a/src/jcloud_docsgen/core/python/definitions.py
+++ b/src/jcloud_docsgen/core/python/definitions.py
@@ -13,14 +13,15 @@
 # limitations under the License.
 
 from __future__ import annotations
-from typing import Union
+
 import ast
-from .arguments import PythonFunctionArgument, PythonASTArgumentsListParser
-from .docstrings import PythonDocstring
 import keyword
+import types
+
 from ...exceptions import InvalidPythonIdentifierError
 from ...utils import assert_that_is_instance
-import types
+from .arguments import PythonASTArgumentsListParser, PythonFunctionArgument
+from .docstrings import PythonDocstring
 
 __all__ = [
     'PythonDefinition',
@@ -30,16 +31,16 @@ __all__ = [
 ]
 
 
-def _python_docstring(doc: Union[str, None]) -> Union[PythonDocstring, None]:
+def _python_docstring(doc: str | None) -> PythonDocstring | None:
     """
     Returns the PythonDocstring object if the docstring is a string and
     not ``None``.
 
     :param doc: The docstring.
-    :type doc: Union[str, None]
+    :type doc: str | None
 
     :return: The PythonDocstring object or ``None``.
-    :rtype: Union[PythonDocstring, None]
+    :rtype: PythonDocstring | None
     """
 
     return PythonDocstring(doc) if doc is not None else None
@@ -53,7 +54,7 @@ class PythonDefinition:
     :param name: The name of the definition.
     :type name: str
     :param doc: The docstring.
-    :type doc: Union[PythonDocstring, None]
+    :type doc: PythonDocstring | None
     :param decorators: The definition decorators.
     :type decorators: list[str]
 
@@ -64,7 +65,7 @@ class PythonDefinition:
     def __init__(
         self,
         name: str,
-        doc: Union[PythonDocstring, None],
+        doc: PythonDocstring | None,
         decorators: list[str],
     ) -> None:
         if keyword.iskeyword(name) or not name.isidentifier() or not name:
@@ -120,9 +121,9 @@ class PythonFunctionDefinition(PythonDefinition):
     :param args: The arguments.
     :type args: list[PythonFunctionArgument]
     :param returns: The return type of the function or class.
-    :type returns: Union[str, None]
+    :type returns: str | None
     :param doc: The docstring.
-    :type doc: Union[PythonDocstring, None]
+    :type doc: PythonDocstring | None
     :param decorators: The definition decorators.
     :type decorators: list[str]
 
@@ -134,8 +135,8 @@ class PythonFunctionDefinition(PythonDefinition):
         self,
         name: str,
         args: list[PythonFunctionArgument],
-        returns: Union[str, None],
-        doc: Union[PythonDocstring, None],
+        returns: str | None,
+        doc: PythonDocstring | None,
         decorators: list[str],
     ) -> None:
         super().__init__(name, doc, decorators)
@@ -179,9 +180,9 @@ class PythonAsyncFunctionDefinition(PythonFunctionDefinition):
     :param args: The arguments.
     :type args: list[PythonFunctionArgument]
     :param returns: The return type of the function or class.
-    :type returns: Union[str, None]
+    :type returns: str | None
     :param doc: The docstring.
-    :type doc: Union[PythonDocstring, None]
+    :type doc: PythonDocstring | None
     :param decorators: The definition decorators.
     :type decorators: list[str]
 
@@ -199,7 +200,7 @@ class PythonClassDefinition(PythonDefinition):
     :param bases: The base classes.
     :type bases: list[str]
     :param doc: The docstring.
-    :type doc: Union[PythonDocstring, None]
+    :type doc: PythonDocstring | None
     :param decorators: The definition decorators.
     :type decorators: list[str]
     :param body:
@@ -213,7 +214,7 @@ class PythonClassDefinition(PythonDefinition):
         self,
         name: str,
         bases: list[str],
-        doc: Union[PythonDocstring, None],
+        doc: PythonDocstring | None,
         decorators: list[str],
         body: list[PythonDefinition],
     ) -> None:
diff --git a/src/jcloud_docsgen/core/python/docstrings.py b/src/jcloud_docsgen/core/python/docstrings.py
index 51c7285..441abb8 100644
--- a/src/jcloud_docsgen/core/python/docstrings.py
+++ b/src/jcloud_docsgen/core/python/docstrings.py
@@ -12,7 +12,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from enum import Enum
 import docstring_parser
 
 __all__ = ['PythonDocstring']
diff --git a/src/jcloud_docsgen/core/python/namespaces.py b/src/jcloud_docsgen/core/python/namespaces.py
index 2dc70b7..e113583 100644
--- a/src/jcloud_docsgen/core/python/namespaces.py
+++ b/src/jcloud_docsgen/core/python/namespaces.py
@@ -13,13 +13,15 @@
 # limitations under the License.
 
 from __future__ import annotations
+
+from typing import TypeAlias, Union
+
 from ...exceptions import (
     InvalidNamespaceError,
-    NamespaceNotFoundError,
     NamespaceExistsError,
+    NamespaceNotFoundError,
 )
 from ...utils import assert_that_is_instance
-from typing import Union, TypeAlias, Dict, List
 
 __all__ = [
     'PythonNamespace',
@@ -51,7 +53,7 @@ class PythonNamespace:
         return f'{type(self).__name__}({self.name!r})'
 
 
-PythonPackageNamespaceDictType: TypeAlias = Dict[
+PythonPackageNamespaceDictType: TypeAlias = dict[
     str,
     Union[
         str,
@@ -73,7 +75,7 @@ class PythonPackageNamespace(PythonNamespace):
     def __init__(
         self,
         name: str,
-        sub_namespaces: List[PythonNamespace],
+        sub_namespaces: list[PythonNamespace],
     ) -> None:
         assert_that_is_instance(sub_namespaces, list)
 
@@ -81,7 +83,7 @@ class PythonPackageNamespace(PythonNamespace):
 
         self._sub_namespaces = sub_namespaces
 
-    def namespace(self, sub_namespaces: List[str]) -> PythonNamespace:
+    def namespace(self, sub_namespaces: list[str]) -> PythonNamespace:
         """
         Returns the namespace object with a specific identifier, such as
         ``['package', 'subpackage', 'module']``.
@@ -205,7 +207,7 @@ class PythonPackageNamespace(PythonNamespace):
             self._sub_namespaces.append(namespace)
 
     @property
-    def sub_namespaces(self) -> List[PythonNamespace]:
+    def sub_namespaces(self) -> list[PythonNamespace]:
         return self._sub_namespaces
 
 
diff --git a/src/jcloud_docsgen/utils.py b/src/jcloud_docsgen/utils.py
index 504c180..197a292 100644
--- a/src/jcloud_docsgen/utils.py
+++ b/src/jcloud_docsgen/utils.py
@@ -16,11 +16,11 @@
 The utilities for jcloud_docsgen
 """
 
-import pathlib
-import os
 import errno
-from typing import Union
+import os
+import pathlib
 import types
+from typing import Union
 
 try:
     from warnings import deprecated
@@ -152,11 +152,7 @@ def _list_type_names(types: list[type]) -> list[str]:
 
 def assert_that_is_instance(
     obj: object,
-    class_or_tuple: Union[
-        type,
-        types.UnionType,
-        tuple[type, ...],
-    ],
+    class_or_tuple: type | types.UnionType | tuple[type, ...],
 ) -> None:
     if not isinstance(class_or_tuple, Union[type, types.UnionType, tuple]):
         raise TypeError(
@@ -185,7 +181,7 @@ def assert_that_is_instance(
         )
 
 
-def non_empty_str(value: Union[str, None]) -> Union[str, None]:
+def non_empty_str(value: str | None) -> str | None:
     """
     Returns the value or ``None``.
 
@@ -195,10 +191,10 @@ def non_empty_str(value: Union[str, None]) -> Union[str, None]:
                  of spaces, it is also considered empty.
 
     :param value: The value.
-    :type value: Union[str, None]
+    :type value: str | None
 
     :return: The value or ``None``.
-    :rtype: Union[str, None]
+    :rtype: str | None
     """
 
     if value is None:
diff --git a/tests/unit/cli/test_parser.py b/tests/unit/cli/test_parser.py
index 9ababcb..c731054 100644
--- a/tests/unit/cli/test_parser.py
+++ b/tests/unit/cli/test_parser.py
@@ -13,6 +13,7 @@
 # limitations under the License.
 
 import pytest
+
 from jcloud_docsgen.cli.cli import create_argument_parser
 
 
diff --git a/tests/unit/cli/test_python.py b/tests/unit/cli/test_python.py
index c858770..70891de 100644
--- a/tests/unit/cli/test_python.py
+++ b/tests/unit/cli/test_python.py
@@ -13,8 +13,11 @@
 # limitations under the License.
 
 import pathlib
+
 import pytest
-from jcloud_docsgen.cli.cli import create_argument_parser, main as cli_main
+
+from jcloud_docsgen.cli.cli import create_argument_parser
+from jcloud_docsgen.cli.cli import main as cli_main
 from jcloud_docsgen.cli.languages.python import parse_sections_list
 from jcloud_docsgen.core.python import (
     PythonDefinitionDocumentationIncludeSections,
diff --git a/tests/unit/core/python/_core/test_PythonDefinitionDocumentationGenerator.py b/tests/unit/core/python/_core/test_PythonDefinitionDocumentationGenerator.py
index 52de56d..b4ec9b5 100644
--- a/tests/unit/core/python/_core/test_PythonDefinitionDocumentationGenerator.py
+++ b/tests/unit/core/python/_core/test_PythonDefinitionDocumentationGenerator.py
@@ -12,21 +12,22 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import pytest
+
 from src.jcloud_docsgen.core.python._core import (
     PythonDefinitionDocumentationGenerator,
     PythonDefinitionDocumentationIncludeSections,
 )
+from src.jcloud_docsgen.core.python.arguments import (
+    PythonArgumentKind,
+    PythonFunctionArgument,
+)
 from src.jcloud_docsgen.core.python.definitions import (
-    PythonFunctionDefinition,
     PythonAsyncFunctionDefinition,
     PythonClassDefinition,
-)
-from src.jcloud_docsgen.core.python.arguments import (
-    PythonFunctionArgument,
-    PythonArgumentKind,
+    PythonFunctionDefinition,
 )
 from src.jcloud_docsgen.core.python.docstrings import PythonDocstring
-import pytest
 
 
 def _signature_section(signature: str) -> str:
diff --git a/tests/unit/core/python/_core/test_PythonDocumentationGenerator.py b/tests/unit/core/python/_core/test_PythonDocumentationGenerator.py
index 047da87..c97d66f 100644
--- a/tests/unit/core/python/_core/test_PythonDocumentationGenerator.py
+++ b/tests/unit/core/python/_core/test_PythonDocumentationGenerator.py
@@ -12,13 +12,15 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import pathlib
+
+import pytest
+
 from src.jcloud_docsgen.core.python import PythonDocumentationGenerator
 from src.jcloud_docsgen.core.python.namespaces import (
     PythonModuleNamespace,
     PythonPackageNamespace,
 )
-import pytest
-import pathlib
 
 
 @pytest.mark.parametrize(
diff --git a/tests/unit/core/python/_core/test_PythonModuleDocumentationGenerator.py b/tests/unit/core/python/_core/test_PythonModuleDocumentationGenerator.py
index 66d9b33..d922136 100644
--- a/tests/unit/core/python/_core/test_PythonModuleDocumentationGenerator.py
+++ b/tests/unit/core/python/_core/test_PythonModuleDocumentationGenerator.py
@@ -12,10 +12,12 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import pathlib
+
+import pytest
+
 from src.jcloud_docsgen.core.python import PythonModuleDocumentationGenerator
 from src.jcloud_docsgen.exceptions import InvalidNamespaceError
-import pathlib
-import pytest
 
 
 @pytest.mark.parametrize(
diff --git a/tests/unit/core/python/_core/test__argument_kind_human_readable.py b/tests/unit/core/python/_core/test__argument_kind_human_readable.py
index cd34bae..b68ed7e 100644
--- a/tests/unit/core/python/_core/test__argument_kind_human_readable.py
+++ b/tests/unit/core/python/_core/test__argument_kind_human_readable.py
@@ -12,9 +12,10 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import pytest
+
 from src.jcloud_docsgen.core.python._core import _argument_kind_human_readable
 from src.jcloud_docsgen.core.python.arguments import PythonArgumentKind
-import pytest
 
 
 @pytest.mark.parametrize(
diff --git a/tests/unit/core/python/_core/test__collect_definitions.py b/tests/unit/core/python/_core/test__collect_definitions.py
index 780694a..fdb4cc3 100644
--- a/tests/unit/core/python/_core/test__collect_definitions.py
+++ b/tests/unit/core/python/_core/test__collect_definitions.py
@@ -12,18 +12,20 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import ast
+
+import pytest
+
 from src.jcloud_docsgen.core.python._core import _collect_definitions
+from src.jcloud_docsgen.core.python.arguments import (
+    PythonArgumentKind,
+    PythonFunctionArgument,
+)
 from src.jcloud_docsgen.core.python.definitions import (
     PythonClassDefinition,
     PythonFunctionDefinition,
 )
-from src.jcloud_docsgen.core.python.arguments import (
-    PythonFunctionArgument,
-    PythonArgumentKind,
-)
 from src.jcloud_docsgen.core.python.docstrings import PythonDocstring
-import pytest
-import ast
 
 
 def module(source_code: str) -> ast.Module:
diff --git a/tests/unit/core/python/_core/test__fit_row_length.py b/tests/unit/core/python/_core/test__fit_row_length.py
index 50686d8..7fc904e 100644
--- a/tests/unit/core/python/_core/test__fit_row_length.py
+++ b/tests/unit/core/python/_core/test__fit_row_length.py
@@ -12,9 +12,10 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from src.jcloud_docsgen.core.python._core import _fit_row_length
 import pytest
 
+from src.jcloud_docsgen.core.python._core import _fit_row_length
+
 
 @pytest.mark.parametrize(
     'expected_length,row,expected',
diff --git a/tests/unit/core/python/_core/test__function_params_info.py b/tests/unit/core/python/_core/test__function_params_info.py
index 825d998..ccb1064 100644
--- a/tests/unit/core/python/_core/test__function_params_info.py
+++ b/tests/unit/core/python/_core/test__function_params_info.py
@@ -12,16 +12,17 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import docstring_parser
+import pytest
+
 from src.jcloud_docsgen.core.python._core import (
     _function_params_info,
     _FunctionParamInfo,
 )
 from src.jcloud_docsgen.core.python.arguments import (
-    PythonFunctionArgument,
     PythonArgumentKind,
+    PythonFunctionArgument,
 )
-import pytest
-import docstring_parser
 
 
 def docstring_args_list(
diff --git a/tests/unit/core/python/_core/test__markdown_table.py b/tests/unit/core/python/_core/test__markdown_table.py
index ac99ec1..ec0081a 100644
--- a/tests/unit/core/python/_core/test__markdown_table.py
+++ b/tests/unit/core/python/_core/test__markdown_table.py
@@ -12,9 +12,10 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from src.jcloud_docsgen.core.python._core import _markdown_table
 import pytest
 
+from src.jcloud_docsgen.core.python._core import _markdown_table
+
 
 @pytest.mark.parametrize(
     (
diff --git a/tests/unit/core/python/_core/test__signature_argument_list.py b/tests/unit/core/python/_core/test__signature_argument_list.py
index 485c6ef..b381864 100644
--- a/tests/unit/core/python/_core/test__signature_argument_list.py
+++ b/tests/unit/core/python/_core/test__signature_argument_list.py
@@ -12,12 +12,13 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import pytest
+
 from src.jcloud_docsgen.core.python._core import _signature_argument_list
 from src.jcloud_docsgen.core.python.arguments import (
-    PythonFunctionArgument,
     PythonArgumentKind,
+    PythonFunctionArgument,
 )
-import pytest
 
 
 @pytest.mark.parametrize(
diff --git a/tests/unit/core/python/arguments/test_PythonASTArgumentsListParser.py b/tests/unit/core/python/arguments/test_PythonASTArgumentsListParser.py
index bb11dec..7af0d65 100644
--- a/tests/unit/core/python/arguments/test_PythonASTArgumentsListParser.py
+++ b/tests/unit/core/python/arguments/test_PythonASTArgumentsListParser.py
@@ -12,13 +12,15 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import ast
+
+import pytest
+
 from src.jcloud_docsgen.core.python.arguments import (
+    PythonArgumentKind,
     PythonASTArgumentsListParser,
     PythonFunctionArgument,
-    PythonArgumentKind,
 )
-import pytest
-import ast
 
 
 def argument_list(argument_list: str) -> ast.arguments:
diff --git a/tests/unit/core/python/arguments/test_PythonFunctionArgument.py b/tests/unit/core/python/arguments/test_PythonFunctionArgument.py
index 5ba42b6..0652165 100644
--- a/tests/unit/core/python/arguments/test_PythonFunctionArgument.py
+++ b/tests/unit/core/python/arguments/test_PythonFunctionArgument.py
@@ -12,16 +12,17 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import pytest
+
 from src.jcloud_docsgen.core.python.arguments import (
-    PythonFunctionArgument,
     PythonArgumentKind,
+    PythonFunctionArgument,
 )
 from src.jcloud_docsgen.exceptions import (
-    InvalidPythonIdentifierError,
     InvalidPythonAnnotationError,
+    InvalidPythonIdentifierError,
     PythonArgumentStructureError,
 )
-import pytest
 
 
 @pytest.mark.parametrize(
diff --git a/tests/unit/core/python/definitions/test_PythonClassDefinition.py b/tests/unit/core/python/definitions/test_PythonClassDefinition.py
index b2f1291..61ec8ac 100644
--- a/tests/unit/core/python/definitions/test_PythonClassDefinition.py
+++ b/tests/unit/core/python/definitions/test_PythonClassDefinition.py
@@ -12,18 +12,19 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from src.jcloud_docsgen.core.python.definitions import (
-    PythonFunctionDefinition,
-    PythonClassDefinition,
-)
+import pytest
+
 from src.jcloud_docsgen.core.python.arguments import (
-    PythonFunctionArgument,
     PythonArgumentKind,
+    PythonFunctionArgument,
+)
+from src.jcloud_docsgen.core.python.definitions import (
+    PythonClassDefinition,
+    PythonFunctionDefinition,
 )
 from src.jcloud_docsgen.core.python.docstrings import PythonDocstring
 from src.jcloud_docsgen.exceptions import InvalidPythonIdentifierError
 from tests.utils.ast_node import ast_node
-import pytest
 
 
 @pytest.mark.parametrize(
diff --git a/tests/unit/core/python/definitions/test_PythonDefinition.py b/tests/unit/core/python/definitions/test_PythonDefinition.py
index da947a5..3b87e32 100644
--- a/tests/unit/core/python/definitions/test_PythonDefinition.py
+++ b/tests/unit/core/python/definitions/test_PythonDefinition.py
@@ -12,10 +12,11 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import pytest
+
 from src.jcloud_docsgen.core.python.definitions import PythonDefinition
 from src.jcloud_docsgen.core.python.docstrings import PythonDocstring
 from src.jcloud_docsgen.exceptions import InvalidPythonIdentifierError
-import pytest
 
 
 @pytest.mark.parametrize(
diff --git a/tests/unit/core/python/definitions/test_PythonFunctionDefinition.py b/tests/unit/core/python/definitions/test_PythonFunctionDefinition.py
index 9cad10b..f385196 100644
--- a/tests/unit/core/python/definitions/test_PythonFunctionDefinition.py
+++ b/tests/unit/core/python/definitions/test_PythonFunctionDefinition.py
@@ -12,15 +12,16 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from src.jcloud_docsgen.core.python.definitions import PythonFunctionDefinition
+import pytest
+
 from src.jcloud_docsgen.core.python.arguments import (
-    PythonFunctionArgument,
     PythonArgumentKind,
+    PythonFunctionArgument,
 )
+from src.jcloud_docsgen.core.python.definitions import PythonFunctionDefinition
 from src.jcloud_docsgen.core.python.docstrings import PythonDocstring
 from src.jcloud_docsgen.exceptions import InvalidPythonIdentifierError
 from tests.utils.ast_node import ast_node
-import pytest
 
 
 @pytest.mark.parametrize(
diff --git a/tests/unit/core/python/namespaces/test_PythonModuleNamespace.py b/tests/unit/core/python/namespaces/test_PythonModuleNamespace.py
index 612e00c..7433a84 100644
--- a/tests/unit/core/python/namespaces/test_PythonModuleNamespace.py
+++ b/tests/unit/core/python/namespaces/test_PythonModuleNamespace.py
@@ -12,9 +12,10 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from src.jcloud_docsgen.core.python.namespaces import PythonModuleNamespace
 import pytest
 
+from src.jcloud_docsgen.core.python.namespaces import PythonModuleNamespace
+
 
 class StrSubclass(str): ...
 
diff --git a/tests/unit/core/python/namespaces/test_PythonNamespace.py b/tests/unit/core/python/namespaces/test_PythonNamespace.py
index 3f845bf..e4ee640 100644
--- a/tests/unit/core/python/namespaces/test_PythonNamespace.py
+++ b/tests/unit/core/python/namespaces/test_PythonNamespace.py
@@ -12,9 +12,10 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from src.jcloud_docsgen.core.python.namespaces import PythonNamespace
 import pytest
 
+from src.jcloud_docsgen.core.python.namespaces import PythonNamespace
+
 
 class StrSubclass(str): ...
 
diff --git a/tests/unit/core/python/namespaces/test_PythonPackageNamespace.py b/tests/unit/core/python/namespaces/test_PythonPackageNamespace.py
index 05d830e..a768e7e 100644
--- a/tests/unit/core/python/namespaces/test_PythonPackageNamespace.py
+++ b/tests/unit/core/python/namespaces/test_PythonPackageNamespace.py
@@ -12,14 +12,15 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from src.jcloud_docsgen.core.python.namespaces import (
-    PythonPackageNamespace,
-    PythonModuleNamespace,
-)
 import pytest
+
+from src.jcloud_docsgen.core.python.namespaces import (
+    PythonModuleNamespace,
+    PythonPackageNamespace,
+)
 from src.jcloud_docsgen.exceptions import (
-    NamespaceNotFoundError,
     InvalidNamespaceError,
+    NamespaceNotFoundError,
 )
 
 
diff --git a/tests/unit/utils/test_assert_that_is_instance.py b/tests/unit/utils/test_assert_that_is_instance.py
index f51009f..739b90b 100644
--- a/tests/unit/utils/test_assert_that_is_instance.py
+++ b/tests/unit/utils/test_assert_that_is_instance.py
@@ -12,10 +12,12 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from src.jcloud_docsgen.utils import assert_that_is_instance
-import pytest
 import types
 
+import pytest
+
+from src.jcloud_docsgen.utils import assert_that_is_instance
+
 
 class TestType: ...
 
diff --git a/tests/unit/utils/test_get_relative_path_segments.py b/tests/unit/utils/test_get_relative_path_segments.py
index a418afd..c69fc9c 100644
--- a/tests/unit/utils/test_get_relative_path_segments.py
+++ b/tests/unit/utils/test_get_relative_path_segments.py
@@ -12,10 +12,12 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from src.jcloud_docsgen.utils import get_relative_path_segments
-import pytest
 import pathlib
 
+import pytest
+
+from src.jcloud_docsgen.utils import get_relative_path_segments
+
 
 @pytest.mark.parametrize(
     'path,root,expected',
diff --git a/tests/unit/utils/test_human_readable_list.py b/tests/unit/utils/test_human_readable_list.py
index 55d1542..12f7f83 100644
--- a/tests/unit/utils/test_human_readable_list.py
+++ b/tests/unit/utils/test_human_readable_list.py
@@ -12,9 +12,10 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from src.jcloud_docsgen.utils import human_readable_list
 import pytest
 
+from src.jcloud_docsgen.utils import human_readable_list
+
 
 @pytest.mark.parametrize(
     'ls,final_separator,quotation_mark,expected',
diff --git a/tests/unit/utils/test_non_empty_str.py b/tests/unit/utils/test_non_empty_str.py
index 3f366ec..2ce7b11 100644
--- a/tests/unit/utils/test_non_empty_str.py
+++ b/tests/unit/utils/test_non_empty_str.py
@@ -12,9 +12,10 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from src.jcloud_docsgen.utils import non_empty_str
 import pytest
 
+from src.jcloud_docsgen.utils import non_empty_str
+
 
 @pytest.mark.parametrize(
     'value,expected',
diff --git a/tests/utils/ast_node.py b/tests/utils/ast_node.py
index 1b164a0..22dd1fc 100644
--- a/tests/utils/ast_node.py
+++ b/tests/utils/ast_node.py
@@ -12,13 +12,12 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from typing import Union
 import ast
 
 __all__ = ['ast_node']
 
 
-def ast_node(statement: str) -> Union[ast.stmt, None]:
+def ast_node(statement: str) -> ast.stmt | None:
     """
     Returns an AST node from the statement.
 
@@ -26,7 +25,7 @@ def ast_node(statement: str) -> Union[ast.stmt, None]:
     :type statement: str
 
     :return: The node.
-    :rtype: Union[ast.stmt, None]
+    :rtype: ast.stmt | None
     """
 
     body = ast.parse(statement).body