Cleanups from Sonar scan

Author: timsavage

src/odin/mapping/__init__.py

@@ -480,8 +480,8 @@ def __getitem__(self, idx):
 
 
 class MappingBase:
-    from_obj: type = None
-    to_obj: type = None
+    from_obj: Optional[type] = None
+    to_obj: Optional[type] = None
 
     # Pending deprecation, move to from_obj and to_obj terminology
     from_resource = None
@@ -747,8 +747,8 @@ class ImmediateMapping(MappingBase, metaclass=MappingMeta):
 def map_field(
     func: _F = None,
     *,
-    from_field: str = None,
-    to_field: str = None,
+    from_field: Union[None, str, Sequence[str]] = None,
+    to_field: Union[None, str, Sequence[str]] = None,
     to_list: bool = False,
 ) -> Union[_F, Callable[[_F], _F]]:
     """Field decorator for custom mappings.
@@ -771,8 +771,8 @@ def inner(fun):
 def map_list_field(
     func: _F = None,
     *,
-    from_field: str = None,
-    to_field: str = None,
+    from_field: Union[None, str, Sequence[str]] = None,
+    to_field: Union[None, str, Sequence[str]] = None,
 ) -> Union[_F, Callable[[_F], _F]]:
     """Field decorator for custom mappings that return a single list.
 
@@ -787,7 +787,7 @@ def map_list_field(
 def assign_field(
     func: _F = None,
     *,
-    to_field: str = None,
+    to_field: Union[None, str, Sequence[str]] = None,
     to_list: bool = False,
 ) -> Union[_F, Callable[[_F], _F]]:
     """Field decorator for assigning a value to destination field without requiring a corresponding source field.

src/odin/traversal.py

@@ -181,9 +181,8 @@ def __next__(self) -> ResourceBase:
                 else:
                     self._field_iters.pop()
 
-            if self.current_resource:
-                if hasattr(self, "on_exit"):
-                    self.on_exit()
+            if self.current_resource and hasattr(self, "on_exit"):
+                self.on_exit()
 
             try:
                 key, next_resource = next(self._resource_iters[-1])

src/odin/utils/ipv6.py

@@ -54,7 +54,7 @@ def is_valid_ipv6_address(ip_str):
         if hextet.count(".") == 3:
             # If we have an IPv4 mapped address, the IPv4 portion has to
             # be at the end of the IPv6 portion.
-            if not ip_str.split(":")[-1] == hextet:
+            if ip_str.split(":")[-1] != hextet:
                 return False
             try:
                 validate_ipv4_address(hextet)

src/odin/validators.py

@@ -3,7 +3,7 @@
 # A note: to use validators from the Django project install the baldr package. Baldr is an integration between Odin and
 # the Django framework, the integration includes support for handling the Django version of the ValidationError
 # exception within Odin.
-from typing import Callable, Any, Union, TypeVar
+from typing import Callable, Any, Union, TypeVar, Optional
 
 import re
 
@@ -19,7 +19,7 @@ class RegexValidator:
     regex = r""
     message = "Enter a valid value."
     code = "invalid"
-    description: str = None
+    description: Optional[str] = None
 
     def __init__(
         self,