diff --git a/modules/openapi-generator/src/main/resources/python/model_anyof.mustache b/modules/openapi-generator/src/main/resources/python/model_anyof.mustache
index 4c00a2a8324..e035e4829b6 100644
--- a/modules/openapi-generator/src/main/resources/python/model_anyof.mustache
+++ b/modules/openapi-generator/src/main/resources/python/model_anyof.mustache
@@ -9,7 +9,7 @@ import re  # noqa: F401
 {{#vendorExtensions.x-py-model-imports}}
 {{{.}}}
 {{/vendorExtensions.x-py-model-imports}}
-from typing import Union, Any, List, TYPE_CHECKING, Optional, Dict
+from typing import Union, Any, List, Set, TYPE_CHECKING, Optional, Dict
 from typing_extensions import Literal, Self
 from pydantic import Field
 
@@ -28,7 +28,7 @@ class {{classname}}({{#parent}}{{{.}}}{{/parent}}{{^parent}}BaseModel{{/parent}}
         actual_instance: Optional[Union[{{#anyOf}}{{{.}}}{{^-last}}, {{/-last}}{{/anyOf}}]] = None
     else:
         actual_instance: Any = None
-    any_of_schemas: List[str] = Field(default=Literal[{{#anyOf}}"{{.}}"{{^-last}}, {{/-last}}{{/anyOf}}])
+    any_of_schemas: Set[str] = { {{#anyOf}}"{{.}}"{{^-last}}, {{/-last}}{{/anyOf}} }
 
     model_config = {
         "validate_assignment": True,
diff --git a/modules/openapi-generator/src/main/resources/python/model_oneof.mustache b/modules/openapi-generator/src/main/resources/python/model_oneof.mustache
index 55d17ba8054..07a4d93f9dd 100644
--- a/modules/openapi-generator/src/main/resources/python/model_oneof.mustache
+++ b/modules/openapi-generator/src/main/resources/python/model_oneof.mustache
@@ -8,7 +8,7 @@ import pprint
 {{{.}}}
 {{/vendorExtensions.x-py-model-imports}}
 from pydantic import StrictStr, Field
-from typing import Union, List, Optional, Dict
+from typing import Union, List, Set, Optional, Dict
 from typing_extensions import Literal, Self
 
 {{#lambda.uppercase}}{{{classname}}}{{/lambda.uppercase}}_ONE_OF_SCHEMAS = [{{#oneOf}}"{{.}}"{{^-last}}, {{/-last}}{{/oneOf}}]
@@ -22,7 +22,7 @@ class {{classname}}({{#parent}}{{{.}}}{{/parent}}{{^parent}}BaseModel{{/parent}}
     {{vendorExtensions.x-py-name}}: {{{vendorExtensions.x-py-typing}}}
 {{/composedSchemas.oneOf}}
     actual_instance: Optional[Union[{{#oneOf}}{{{.}}}{{^-last}}, {{/-last}}{{/oneOf}}]] = None
-    one_of_schemas: List[str] = Field(default=Literal[{{#oneOf}}"{{.}}"{{^-last}}, {{/-last}}{{/oneOf}}])
+    one_of_schemas: Set[str] = { {{#oneOf}}"{{.}}"{{^-last}}, {{/-last}}{{/oneOf}} }
 
     model_config = ConfigDict(
         validate_assignment=True,
diff --git a/samples/openapi3/client/petstore/python-aiohttp/petstore_api/models/any_of_color.py b/samples/openapi3/client/petstore/python-aiohttp/petstore_api/models/any_of_color.py
index 4dd958387d3..f6d277e7949 100644
--- a/samples/openapi3/client/petstore/python-aiohttp/petstore_api/models/any_of_color.py
+++ b/samples/openapi3/client/petstore/python-aiohttp/petstore_api/models/any_of_color.py
@@ -20,7 +20,7 @@ import re  # noqa: F401
 from pydantic import BaseModel, ConfigDict, Field, StrictStr, ValidationError, field_validator
 from typing import List, Optional
 from typing_extensions import Annotated
-from typing import Union, Any, List, TYPE_CHECKING, Optional, Dict
+from typing import Union, Any, List, Set, TYPE_CHECKING, Optional, Dict
 from typing_extensions import Literal, Self
 from pydantic import Field
 
@@ -41,7 +41,7 @@ class AnyOfColor(BaseModel):
         actual_instance: Optional[Union[List[int], str]] = None
     else:
         actual_instance: Any = None
-    any_of_schemas: List[str] = Field(default=Literal["List[int]", "str"])
+    any_of_schemas: Set[str] = { "List[int]", "str" }
 
     model_config = {
         "validate_assignment": True,
diff --git a/samples/openapi3/client/petstore/python-aiohttp/petstore_api/models/any_of_pig.py b/samples/openapi3/client/petstore/python-aiohttp/petstore_api/models/any_of_pig.py
index 5ff976e3cce..c949e136f41 100644
--- a/samples/openapi3/client/petstore/python-aiohttp/petstore_api/models/any_of_pig.py
+++ b/samples/openapi3/client/petstore/python-aiohttp/petstore_api/models/any_of_pig.py
@@ -21,7 +21,7 @@ from pydantic import BaseModel, ConfigDict, Field, StrictStr, ValidationError, f
 from typing import Optional
 from petstore_api.models.basque_pig import BasquePig
 from petstore_api.models.danish_pig import DanishPig
-from typing import Union, Any, List, TYPE_CHECKING, Optional, Dict
+from typing import Union, Any, List, Set, TYPE_CHECKING, Optional, Dict
 from typing_extensions import Literal, Self
 from pydantic import Field
 
@@ -40,7 +40,7 @@ class AnyOfPig(BaseModel):
         actual_instance: Optional[Union[BasquePig, DanishPig]] = None
     else:
         actual_instance: Any = None
-    any_of_schemas: List[str] = Field(default=Literal["BasquePig", "DanishPig"])
+    any_of_schemas: Set[str] = { "BasquePig", "DanishPig" }
 
     model_config = {
         "validate_assignment": True,
diff --git a/samples/openapi3/client/petstore/python-aiohttp/petstore_api/models/color.py b/samples/openapi3/client/petstore/python-aiohttp/petstore_api/models/color.py
index 0f89c3d81e3..bb740fb597d 100644
--- a/samples/openapi3/client/petstore/python-aiohttp/petstore_api/models/color.py
+++ b/samples/openapi3/client/petstore/python-aiohttp/petstore_api/models/color.py
@@ -19,7 +19,7 @@ from pydantic import BaseModel, ConfigDict, Field, StrictStr, ValidationError, f
 from typing import Any, List, Optional
 from typing_extensions import Annotated
 from pydantic import StrictStr, Field
-from typing import Union, List, Optional, Dict
+from typing import Union, List, Set, Optional, Dict
 from typing_extensions import Literal, Self
 
 COLOR_ONE_OF_SCHEMAS = ["List[int]", "str"]
@@ -35,7 +35,7 @@ class Color(BaseModel):
     # data type: str
     oneof_schema_3_validator: Optional[Annotated[str, Field(min_length=7, strict=True, max_length=7)]] = Field(default=None, description="Hex color string, such as #00FF00.")
     actual_instance: Optional[Union[List[int], str]] = None
-    one_of_schemas: List[str] = Field(default=Literal["List[int]", "str"])
+    one_of_schemas: Set[str] = { "List[int]", "str" }
 
     model_config = ConfigDict(
         validate_assignment=True,
diff --git a/samples/openapi3/client/petstore/python-aiohttp/petstore_api/models/int_or_string.py b/samples/openapi3/client/petstore/python-aiohttp/petstore_api/models/int_or_string.py
index 102540e15e1..f2a5a0a2d4a 100644
--- a/samples/openapi3/client/petstore/python-aiohttp/petstore_api/models/int_or_string.py
+++ b/samples/openapi3/client/petstore/python-aiohttp/petstore_api/models/int_or_string.py
@@ -19,7 +19,7 @@ from pydantic import BaseModel, ConfigDict, Field, StrictStr, ValidationError, f
 from typing import Any, List, Optional
 from typing_extensions import Annotated
 from pydantic import StrictStr, Field
-from typing import Union, List, Optional, Dict
+from typing import Union, List, Set, Optional, Dict
 from typing_extensions import Literal, Self
 
 INTORSTRING_ONE_OF_SCHEMAS = ["int", "str"]
@@ -33,7 +33,7 @@ class IntOrString(BaseModel):
     # data type: str
     oneof_schema_2_validator: Optional[StrictStr] = None
     actual_instance: Optional[Union[int, str]] = None
-    one_of_schemas: List[str] = Field(default=Literal["int", "str"])
+    one_of_schemas: Set[str] = { "int", "str" }
 
     model_config = ConfigDict(
         validate_assignment=True,
diff --git a/samples/openapi3/client/petstore/python-aiohttp/petstore_api/models/one_of_enum_string.py b/samples/openapi3/client/petstore/python-aiohttp/petstore_api/models/one_of_enum_string.py
index 27ab1abf97f..f180178737d 100644
--- a/samples/openapi3/client/petstore/python-aiohttp/petstore_api/models/one_of_enum_string.py
+++ b/samples/openapi3/client/petstore/python-aiohttp/petstore_api/models/one_of_enum_string.py
@@ -20,7 +20,7 @@ from typing import Any, List, Optional
 from petstore_api.models.enum_string1 import EnumString1
 from petstore_api.models.enum_string2 import EnumString2
 from pydantic import StrictStr, Field
-from typing import Union, List, Optional, Dict
+from typing import Union, List, Set, Optional, Dict
 from typing_extensions import Literal, Self
 
 ONEOFENUMSTRING_ONE_OF_SCHEMAS = ["EnumString1", "EnumString2"]
@@ -34,7 +34,7 @@ class OneOfEnumString(BaseModel):
     # data type: EnumString2
     oneof_schema_2_validator: Optional[EnumString2] = None
     actual_instance: Optional[Union[EnumString1, EnumString2]] = None
-    one_of_schemas: List[str] = Field(default=Literal["EnumString1", "EnumString2"])
+    one_of_schemas: Set[str] = { "EnumString1", "EnumString2" }
 
     model_config = ConfigDict(
         validate_assignment=True,
diff --git a/samples/openapi3/client/petstore/python-aiohttp/petstore_api/models/pig.py b/samples/openapi3/client/petstore/python-aiohttp/petstore_api/models/pig.py
index 7d4a9ae4671..b3a759e89b7 100644
--- a/samples/openapi3/client/petstore/python-aiohttp/petstore_api/models/pig.py
+++ b/samples/openapi3/client/petstore/python-aiohttp/petstore_api/models/pig.py
@@ -20,7 +20,7 @@ from typing import Any, List, Optional
 from petstore_api.models.basque_pig import BasquePig
 from petstore_api.models.danish_pig import DanishPig
 from pydantic import StrictStr, Field
-from typing import Union, List, Optional, Dict
+from typing import Union, List, Set, Optional, Dict
 from typing_extensions import Literal, Self
 
 PIG_ONE_OF_SCHEMAS = ["BasquePig", "DanishPig"]
@@ -34,7 +34,7 @@ class Pig(BaseModel):
     # data type: DanishPig
     oneof_schema_2_validator: Optional[DanishPig] = None
     actual_instance: Optional[Union[BasquePig, DanishPig]] = None
-    one_of_schemas: List[str] = Field(default=Literal["BasquePig", "DanishPig"])
+    one_of_schemas: Set[str] = { "BasquePig", "DanishPig" }
 
     model_config = ConfigDict(
         validate_assignment=True,
diff --git a/samples/openapi3/client/petstore/python-aiohttp/petstore_api/models/task_activity.py b/samples/openapi3/client/petstore/python-aiohttp/petstore_api/models/task_activity.py
index 9494a1a1167..cc1e1fc5a60 100644
--- a/samples/openapi3/client/petstore/python-aiohttp/petstore_api/models/task_activity.py
+++ b/samples/openapi3/client/petstore/python-aiohttp/petstore_api/models/task_activity.py
@@ -21,7 +21,7 @@ from petstore_api.models.bathing import Bathing
 from petstore_api.models.feeding import Feeding
 from petstore_api.models.poop_cleaning import PoopCleaning
 from pydantic import StrictStr, Field
-from typing import Union, List, Optional, Dict
+from typing import Union, List, Set, Optional, Dict
 from typing_extensions import Literal, Self
 
 TASKACTIVITY_ONE_OF_SCHEMAS = ["Bathing", "Feeding", "PoopCleaning"]
@@ -37,7 +37,7 @@ class TaskActivity(BaseModel):
     # data type: Bathing
     oneof_schema_3_validator: Optional[Bathing] = None
     actual_instance: Optional[Union[Bathing, Feeding, PoopCleaning]] = None
-    one_of_schemas: List[str] = Field(default=Literal["Bathing", "Feeding", "PoopCleaning"])
+    one_of_schemas: Set[str] = { "Bathing", "Feeding", "PoopCleaning" }
 
     model_config = ConfigDict(
         validate_assignment=True,
diff --git a/samples/openapi3/client/petstore/python/petstore_api/models/any_of_color.py b/samples/openapi3/client/petstore/python/petstore_api/models/any_of_color.py
index 4dd958387d3..f6d277e7949 100644
--- a/samples/openapi3/client/petstore/python/petstore_api/models/any_of_color.py
+++ b/samples/openapi3/client/petstore/python/petstore_api/models/any_of_color.py
@@ -20,7 +20,7 @@ import re  # noqa: F401
 from pydantic import BaseModel, ConfigDict, Field, StrictStr, ValidationError, field_validator
 from typing import List, Optional
 from typing_extensions import Annotated
-from typing import Union, Any, List, TYPE_CHECKING, Optional, Dict
+from typing import Union, Any, List, Set, TYPE_CHECKING, Optional, Dict
 from typing_extensions import Literal, Self
 from pydantic import Field
 
@@ -41,7 +41,7 @@ class AnyOfColor(BaseModel):
         actual_instance: Optional[Union[List[int], str]] = None
     else:
         actual_instance: Any = None
-    any_of_schemas: List[str] = Field(default=Literal["List[int]", "str"])
+    any_of_schemas: Set[str] = { "List[int]", "str" }
 
     model_config = {
         "validate_assignment": True,
diff --git a/samples/openapi3/client/petstore/python/petstore_api/models/any_of_pig.py b/samples/openapi3/client/petstore/python/petstore_api/models/any_of_pig.py
index 5ff976e3cce..c949e136f41 100644
--- a/samples/openapi3/client/petstore/python/petstore_api/models/any_of_pig.py
+++ b/samples/openapi3/client/petstore/python/petstore_api/models/any_of_pig.py
@@ -21,7 +21,7 @@ from pydantic import BaseModel, ConfigDict, Field, StrictStr, ValidationError, f
 from typing import Optional
 from petstore_api.models.basque_pig import BasquePig
 from petstore_api.models.danish_pig import DanishPig
-from typing import Union, Any, List, TYPE_CHECKING, Optional, Dict
+from typing import Union, Any, List, Set, TYPE_CHECKING, Optional, Dict
 from typing_extensions import Literal, Self
 from pydantic import Field
 
@@ -40,7 +40,7 @@ class AnyOfPig(BaseModel):
         actual_instance: Optional[Union[BasquePig, DanishPig]] = None
     else:
         actual_instance: Any = None
-    any_of_schemas: List[str] = Field(default=Literal["BasquePig", "DanishPig"])
+    any_of_schemas: Set[str] = { "BasquePig", "DanishPig" }
 
     model_config = {
         "validate_assignment": True,
diff --git a/samples/openapi3/client/petstore/python/petstore_api/models/color.py b/samples/openapi3/client/petstore/python/petstore_api/models/color.py
index 0f89c3d81e3..bb740fb597d 100644
--- a/samples/openapi3/client/petstore/python/petstore_api/models/color.py
+++ b/samples/openapi3/client/petstore/python/petstore_api/models/color.py
@@ -19,7 +19,7 @@ from pydantic import BaseModel, ConfigDict, Field, StrictStr, ValidationError, f
 from typing import Any, List, Optional
 from typing_extensions import Annotated
 from pydantic import StrictStr, Field
-from typing import Union, List, Optional, Dict
+from typing import Union, List, Set, Optional, Dict
 from typing_extensions import Literal, Self
 
 COLOR_ONE_OF_SCHEMAS = ["List[int]", "str"]
@@ -35,7 +35,7 @@ class Color(BaseModel):
     # data type: str
     oneof_schema_3_validator: Optional[Annotated[str, Field(min_length=7, strict=True, max_length=7)]] = Field(default=None, description="Hex color string, such as #00FF00.")
     actual_instance: Optional[Union[List[int], str]] = None
-    one_of_schemas: List[str] = Field(default=Literal["List[int]", "str"])
+    one_of_schemas: Set[str] = { "List[int]", "str" }
 
     model_config = ConfigDict(
         validate_assignment=True,
diff --git a/samples/openapi3/client/petstore/python/petstore_api/models/int_or_string.py b/samples/openapi3/client/petstore/python/petstore_api/models/int_or_string.py
index 102540e15e1..f2a5a0a2d4a 100644
--- a/samples/openapi3/client/petstore/python/petstore_api/models/int_or_string.py
+++ b/samples/openapi3/client/petstore/python/petstore_api/models/int_or_string.py
@@ -19,7 +19,7 @@ from pydantic import BaseModel, ConfigDict, Field, StrictStr, ValidationError, f
 from typing import Any, List, Optional
 from typing_extensions import Annotated
 from pydantic import StrictStr, Field
-from typing import Union, List, Optional, Dict
+from typing import Union, List, Set, Optional, Dict
 from typing_extensions import Literal, Self
 
 INTORSTRING_ONE_OF_SCHEMAS = ["int", "str"]
@@ -33,7 +33,7 @@ class IntOrString(BaseModel):
     # data type: str
     oneof_schema_2_validator: Optional[StrictStr] = None
     actual_instance: Optional[Union[int, str]] = None
-    one_of_schemas: List[str] = Field(default=Literal["int", "str"])
+    one_of_schemas: Set[str] = { "int", "str" }
 
     model_config = ConfigDict(
         validate_assignment=True,
diff --git a/samples/openapi3/client/petstore/python/petstore_api/models/one_of_enum_string.py b/samples/openapi3/client/petstore/python/petstore_api/models/one_of_enum_string.py
index 27ab1abf97f..f180178737d 100644
--- a/samples/openapi3/client/petstore/python/petstore_api/models/one_of_enum_string.py
+++ b/samples/openapi3/client/petstore/python/petstore_api/models/one_of_enum_string.py
@@ -20,7 +20,7 @@ from typing import Any, List, Optional
 from petstore_api.models.enum_string1 import EnumString1
 from petstore_api.models.enum_string2 import EnumString2
 from pydantic import StrictStr, Field
-from typing import Union, List, Optional, Dict
+from typing import Union, List, Set, Optional, Dict
 from typing_extensions import Literal, Self
 
 ONEOFENUMSTRING_ONE_OF_SCHEMAS = ["EnumString1", "EnumString2"]
@@ -34,7 +34,7 @@ class OneOfEnumString(BaseModel):
     # data type: EnumString2
     oneof_schema_2_validator: Optional[EnumString2] = None
     actual_instance: Optional[Union[EnumString1, EnumString2]] = None
-    one_of_schemas: List[str] = Field(default=Literal["EnumString1", "EnumString2"])
+    one_of_schemas: Set[str] = { "EnumString1", "EnumString2" }
 
     model_config = ConfigDict(
         validate_assignment=True,
diff --git a/samples/openapi3/client/petstore/python/petstore_api/models/pig.py b/samples/openapi3/client/petstore/python/petstore_api/models/pig.py
index 4e9f0223199..06798245b8f 100644
--- a/samples/openapi3/client/petstore/python/petstore_api/models/pig.py
+++ b/samples/openapi3/client/petstore/python/petstore_api/models/pig.py
@@ -20,7 +20,7 @@ from typing import Any, List, Optional
 from petstore_api.models.basque_pig import BasquePig
 from petstore_api.models.danish_pig import DanishPig
 from pydantic import StrictStr, Field
-from typing import Union, List, Optional, Dict
+from typing import Union, List, Set, Optional, Dict
 from typing_extensions import Literal, Self
 
 PIG_ONE_OF_SCHEMAS = ["BasquePig", "DanishPig"]
@@ -34,7 +34,7 @@ class Pig(BaseModel):
     # data type: DanishPig
     oneof_schema_2_validator: Optional[DanishPig] = None
     actual_instance: Optional[Union[BasquePig, DanishPig]] = None
-    one_of_schemas: List[str] = Field(default=Literal["BasquePig", "DanishPig"])
+    one_of_schemas: Set[str] = { "BasquePig", "DanishPig" }
 
     model_config = ConfigDict(
         validate_assignment=True,
diff --git a/samples/openapi3/client/petstore/python/petstore_api/models/task_activity.py b/samples/openapi3/client/petstore/python/petstore_api/models/task_activity.py
index 9494a1a1167..cc1e1fc5a60 100644
--- a/samples/openapi3/client/petstore/python/petstore_api/models/task_activity.py
+++ b/samples/openapi3/client/petstore/python/petstore_api/models/task_activity.py
@@ -21,7 +21,7 @@ from petstore_api.models.bathing import Bathing
 from petstore_api.models.feeding import Feeding
 from petstore_api.models.poop_cleaning import PoopCleaning
 from pydantic import StrictStr, Field
-from typing import Union, List, Optional, Dict
+from typing import Union, List, Set, Optional, Dict
 from typing_extensions import Literal, Self
 
 TASKACTIVITY_ONE_OF_SCHEMAS = ["Bathing", "Feeding", "PoopCleaning"]
@@ -37,7 +37,7 @@ class TaskActivity(BaseModel):
     # data type: Bathing
     oneof_schema_3_validator: Optional[Bathing] = None
     actual_instance: Optional[Union[Bathing, Feeding, PoopCleaning]] = None
-    one_of_schemas: List[str] = Field(default=Literal["Bathing", "Feeding", "PoopCleaning"])
+    one_of_schemas: Set[str] = { "Bathing", "Feeding", "PoopCleaning" }
 
     model_config = ConfigDict(
         validate_assignment=True,