Fix 18271: Circular imports on AllOf generation with REFACTOR_ALLOF_WITH_PROPERTIES_ONLY=True (#18272)

* fix issue 18271

* the same update for python-pydantic-v1

* add test

* update samples

* update samples

* put properties under allOf for python client tests

* update samples

* add a test in test model

samples/openapi3/client/petstore/python/.openapi-generator/FILES

@@ -7,6 +7,7 @@ docs/AdditionalPropertiesAnyType.md
 docs/AdditionalPropertiesClass.md
 docs/AdditionalPropertiesObject.md
 docs/AdditionalPropertiesWithDescriptionOnly.md
+docs/AllOfSuperModel.md
 docs/AllOfWithSingleRef.md
 docs/Animal.md
 docs/AnotherFakeApi.md
@@ -21,6 +22,7 @@ docs/Bathing.md
 docs/Capitalization.md
 docs/Cat.md
 docs/Category.md
+docs/CircularAllOfRef.md
 docs/CircularReferenceModel.md
 docs/ClassModel.md
 docs/Client.md
@@ -85,6 +87,7 @@ docs/PoopCleaning.md
 docs/PropertyMap.md
 docs/PropertyNameCollision.md
 docs/ReadOnlyFirst.md
+docs/SecondCircularAllOfRef.md
 docs/SecondRef.md
 docs/SelfReferenceModel.md
 docs/SingleRefType.md
@@ -125,6 +128,7 @@ petstore_api/models/additional_properties_any_type.py
 petstore_api/models/additional_properties_class.py
 petstore_api/models/additional_properties_object.py
 petstore_api/models/additional_properties_with_description_only.py
+petstore_api/models/all_of_super_model.py
 petstore_api/models/all_of_with_single_ref.py
 petstore_api/models/animal.py
 petstore_api/models/any_of_color.py
@@ -138,6 +142,7 @@ petstore_api/models/bathing.py
 petstore_api/models/capitalization.py
 petstore_api/models/cat.py
 petstore_api/models/category.py
+petstore_api/models/circular_all_of_ref.py
 petstore_api/models/circular_reference_model.py
 petstore_api/models/class_model.py
 petstore_api/models/client.py
@@ -197,6 +202,7 @@ petstore_api/models/poop_cleaning.py
 petstore_api/models/property_map.py
 petstore_api/models/property_name_collision.py
 petstore_api/models/read_only_first.py
+petstore_api/models/second_circular_all_of_ref.py
 petstore_api/models/second_ref.py
 petstore_api/models/self_reference_model.py
 petstore_api/models/single_ref_type.py

samples/openapi3/client/petstore/python/README.md

@@ -154,6 +154,7 @@ Class | Method | HTTP request | Description
  - [AdditionalPropertiesClass](docs/AdditionalPropertiesClass.md)
  - [AdditionalPropertiesObject](docs/AdditionalPropertiesObject.md)
  - [AdditionalPropertiesWithDescriptionOnly](docs/AdditionalPropertiesWithDescriptionOnly.md)
+ - [AllOfSuperModel](docs/AllOfSuperModel.md)
  - [AllOfWithSingleRef](docs/AllOfWithSingleRef.md)
  - [Animal](docs/Animal.md)
  - [AnyOfColor](docs/AnyOfColor.md)
@@ -167,6 +168,7 @@ Class | Method | HTTP request | Description
  - [Capitalization](docs/Capitalization.md)
  - [Cat](docs/Cat.md)
  - [Category](docs/Category.md)
+ - [CircularAllOfRef](docs/CircularAllOfRef.md)
  - [CircularReferenceModel](docs/CircularReferenceModel.md)
  - [ClassModel](docs/ClassModel.md)
  - [Client](docs/Client.md)
@@ -226,6 +228,7 @@ Class | Method | HTTP request | Description
  - [PropertyMap](docs/PropertyMap.md)
  - [PropertyNameCollision](docs/PropertyNameCollision.md)
  - [ReadOnlyFirst](docs/ReadOnlyFirst.md)
+ - [SecondCircularAllOfRef](docs/SecondCircularAllOfRef.md)
  - [SecondRef](docs/SecondRef.md)
  - [SelfReferenceModel](docs/SelfReferenceModel.md)
  - [SingleRefType](docs/SingleRefType.md)

samples/openapi3/client/petstore/python/docs/AllOfSuperModel.md

@@ -0,0 +1,29 @@
+# AllOfSuperModel
+
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**name** | **str** |  | [optional] 
+
+## Example
+
+```python
+from petstore_api.models.all_of_super_model import AllOfSuperModel
+
+# TODO update the JSON string below
+json = "{}"
+# create an instance of AllOfSuperModel from a JSON string
+all_of_super_model_instance = AllOfSuperModel.from_json(json)
+# print the JSON string representation of the object
+print(AllOfSuperModel.to_json())
+
+# convert the object into a dict
+all_of_super_model_dict = all_of_super_model_instance.to_dict()
+# create an instance of AllOfSuperModel from a dict
+all_of_super_model_form_dict = all_of_super_model.from_dict(all_of_super_model_dict)
+```
+[[Back to Model list]](../README.md#documentation-for-models) [[Back to API list]](../README.md#documentation-for-api-endpoints) [[Back to README]](../README.md)
+
+

samples/openapi3/client/petstore/python/docs/CircularAllOfRef.md

@@ -0,0 +1,30 @@
+# CircularAllOfRef
+
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**name** | **str** |  | [optional] 
+**second_circular_all_of_ref** | [**List[SecondCircularAllOfRef]**](SecondCircularAllOfRef.md) |  | [optional] 
+
+## Example
+
+```python
+from petstore_api.models.circular_all_of_ref import CircularAllOfRef
+
+# TODO update the JSON string below
+json = "{}"
+# create an instance of CircularAllOfRef from a JSON string
+circular_all_of_ref_instance = CircularAllOfRef.from_json(json)
+# print the JSON string representation of the object
+print(CircularAllOfRef.to_json())
+
+# convert the object into a dict
+circular_all_of_ref_dict = circular_all_of_ref_instance.to_dict()
+# create an instance of CircularAllOfRef from a dict
+circular_all_of_ref_form_dict = circular_all_of_ref.from_dict(circular_all_of_ref_dict)
+```
+[[Back to Model list]](../README.md#documentation-for-models) [[Back to API list]](../README.md#documentation-for-api-endpoints) [[Back to README]](../README.md)
+
+

samples/openapi3/client/petstore/python/docs/SecondCircularAllOfRef.md

@@ -0,0 +1,30 @@
+# SecondCircularAllOfRef
+
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**name** | **str** |  | [optional] 
+**circular_all_of_ref** | [**List[CircularAllOfRef]**](CircularAllOfRef.md) |  | [optional] 
+
+## Example
+
+```python
+from petstore_api.models.second_circular_all_of_ref import SecondCircularAllOfRef
+
+# TODO update the JSON string below
+json = "{}"
+# create an instance of SecondCircularAllOfRef from a JSON string
+second_circular_all_of_ref_instance = SecondCircularAllOfRef.from_json(json)
+# print the JSON string representation of the object
+print(SecondCircularAllOfRef.to_json())
+
+# convert the object into a dict
+second_circular_all_of_ref_dict = second_circular_all_of_ref_instance.to_dict()
+# create an instance of SecondCircularAllOfRef from a dict
+second_circular_all_of_ref_form_dict = second_circular_all_of_ref.from_dict(second_circular_all_of_ref_dict)
+```
+[[Back to Model list]](../README.md#documentation-for-models) [[Back to API list]](../README.md#documentation-for-api-endpoints) [[Back to README]](../README.md)
+
+

samples/openapi3/client/petstore/python/petstore_api/__init__.py

@@ -43,6 +43,7 @@ from petstore_api.models.additional_properties_any_type import AdditionalPropert
 from petstore_api.models.additional_properties_class import AdditionalPropertiesClass
 from petstore_api.models.additional_properties_object import AdditionalPropertiesObject
 from petstore_api.models.additional_properties_with_description_only import AdditionalPropertiesWithDescriptionOnly
+from petstore_api.models.all_of_super_model import AllOfSuperModel
 from petstore_api.models.all_of_with_single_ref import AllOfWithSingleRef
 from petstore_api.models.animal import Animal
 from petstore_api.models.any_of_color import AnyOfColor
@@ -56,6 +57,7 @@ from petstore_api.models.bathing import Bathing
 from petstore_api.models.capitalization import Capitalization
 from petstore_api.models.cat import Cat
 from petstore_api.models.category import Category
+from petstore_api.models.circular_all_of_ref import CircularAllOfRef
 from petstore_api.models.circular_reference_model import CircularReferenceModel
 from petstore_api.models.class_model import ClassModel
 from petstore_api.models.client import Client
@@ -115,6 +117,7 @@ from petstore_api.models.poop_cleaning import PoopCleaning
 from petstore_api.models.property_map import PropertyMap
 from petstore_api.models.property_name_collision import PropertyNameCollision
 from petstore_api.models.read_only_first import ReadOnlyFirst
+from petstore_api.models.second_circular_all_of_ref import SecondCircularAllOfRef
 from petstore_api.models.second_ref import SecondRef
 from petstore_api.models.self_reference_model import SelfReferenceModel
 from petstore_api.models.single_ref_type import SingleRefType

samples/openapi3/client/petstore/python/petstore_api/models/__init__.py

@@ -18,6 +18,7 @@ from petstore_api.models.additional_properties_any_type import AdditionalPropert
 from petstore_api.models.additional_properties_class import AdditionalPropertiesClass
 from petstore_api.models.additional_properties_object import AdditionalPropertiesObject
 from petstore_api.models.additional_properties_with_description_only import AdditionalPropertiesWithDescriptionOnly
+from petstore_api.models.all_of_super_model import AllOfSuperModel
 from petstore_api.models.all_of_with_single_ref import AllOfWithSingleRef
 from petstore_api.models.animal import Animal
 from petstore_api.models.any_of_color import AnyOfColor
@@ -31,6 +32,7 @@ from petstore_api.models.bathing import Bathing
 from petstore_api.models.capitalization import Capitalization
 from petstore_api.models.cat import Cat
 from petstore_api.models.category import Category
+from petstore_api.models.circular_all_of_ref import CircularAllOfRef
 from petstore_api.models.circular_reference_model import CircularReferenceModel
 from petstore_api.models.class_model import ClassModel
 from petstore_api.models.client import Client
@@ -90,6 +92,7 @@ from petstore_api.models.poop_cleaning import PoopCleaning
 from petstore_api.models.property_map import PropertyMap
 from petstore_api.models.property_name_collision import PropertyNameCollision
 from petstore_api.models.read_only_first import ReadOnlyFirst
+from petstore_api.models.second_circular_all_of_ref import SecondCircularAllOfRef
 from petstore_api.models.second_ref import SecondRef
 from petstore_api.models.self_reference_model import SelfReferenceModel
 from petstore_api.models.single_ref_type import SingleRefType

samples/openapi3/client/petstore/python/petstore_api/models/all_of_super_model.py

@@ -0,0 +1,100 @@
+# coding: utf-8
+
+"""
+    OpenAPI Petstore
+
+    This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+
+    The version of the OpenAPI document: 1.0.0
+    Generated by OpenAPI Generator (https://openapi-generator.tech)
+
+    Do not edit the class manually.
+"""  # noqa: E501
+
+
+from __future__ import annotations
+import pprint
+import re  # noqa: F401
+import json
+
+from pydantic import BaseModel, ConfigDict, Field, StrictStr
+from typing import Any, ClassVar, Dict, List, Optional
+from typing import Optional, Set
+from typing_extensions import Self
+
+class AllOfSuperModel(BaseModel):
+    """
+    AllOfSuperModel
+    """ # noqa: E501
+    name: Optional[StrictStr] = Field(default=None, alias="_name")
+    additional_properties: Dict[str, Any] = {}
+    __properties: ClassVar[List[str]] = ["_name"]
+
+    model_config = ConfigDict(
+        populate_by_name=True,
+        validate_assignment=True,
+        protected_namespaces=(),
+    )
+
+
+    def to_str(self) -> str:
+        """Returns the string representation of the model using alias"""
+        return pprint.pformat(self.model_dump(by_alias=True))
+
+    def to_json(self) -> str:
+        """Returns the JSON representation of the model using alias"""
+        # TODO: pydantic v2: use .model_dump_json(by_alias=True, exclude_unset=True) instead
+        return json.dumps(self.to_dict())
+
+    @classmethod
+    def from_json(cls, json_str: str) -> Optional[Self]:
+        """Create an instance of AllOfSuperModel from a JSON string"""
+        return cls.from_dict(json.loads(json_str))
+
+    def to_dict(self) -> Dict[str, Any]:
+        """Return the dictionary representation of the model using alias.
+
+        This has the following differences from calling pydantic's
+        `self.model_dump(by_alias=True)`:
+
+        * `None` is only added to the output dict for nullable fields that
+          were set at model initialization. Other fields with value `None`
+          are ignored.
+        * Fields in `self.additional_properties` are added to the output dict.
+        """
+        excluded_fields: Set[str] = set([
+            "additional_properties",
+        ])
+
+        _dict = self.model_dump(
+            by_alias=True,
+            exclude=excluded_fields,
+            exclude_none=True,
+        )
+        # puts key-value pairs in additional_properties in the top level
+        if self.additional_properties is not None:
+            for _key, _value in self.additional_properties.items():
+                _dict[_key] = _value
+
+        return _dict
+
+    @classmethod
+    def from_dict(cls, obj: Optional[Dict[str, Any]]) -> Optional[Self]:
+        """Create an instance of AllOfSuperModel from a dict"""
+        if obj is None:
+            return None
+
+        if not isinstance(obj, dict):
+            return cls.model_validate(obj)
+
+        _obj = cls.model_validate({
+            "_name": obj.get("_name")
+        })
+        # store additional fields in additional_properties
+        for _key in obj.keys():
+            if _key not in cls.__properties:
+                _obj.additional_properties[_key] = obj.get(_key)
+
+        return _obj
+
+

samples/openapi3/client/petstore/python/petstore_api/models/circular_all_of_ref.py

@@ -0,0 +1,112 @@
+# coding: utf-8
+
+"""
+    OpenAPI Petstore
+
+    This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+
+    The version of the OpenAPI document: 1.0.0
+    Generated by OpenAPI Generator (https://openapi-generator.tech)
+
+    Do not edit the class manually.
+"""  # noqa: E501
+
+
+from __future__ import annotations
+import pprint
+import re  # noqa: F401
+import json
+
+from pydantic import BaseModel, ConfigDict, Field, StrictStr
+from typing import Any, ClassVar, Dict, List, Optional
+from typing import Optional, Set
+from typing_extensions import Self
+
+class CircularAllOfRef(BaseModel):
+    """
+    CircularAllOfRef
+    """ # noqa: E501
+    name: Optional[StrictStr] = Field(default=None, alias="_name")
+    second_circular_all_of_ref: Optional[List[SecondCircularAllOfRef]] = Field(default=None, alias="secondCircularAllOfRef")
+    additional_properties: Dict[str, Any] = {}
+    __properties: ClassVar[List[str]] = ["_name", "secondCircularAllOfRef"]
+
+    model_config = ConfigDict(
+        populate_by_name=True,
+        validate_assignment=True,
+        protected_namespaces=(),
+    )
+
+
+    def to_str(self) -> str:
+        """Returns the string representation of the model using alias"""
+        return pprint.pformat(self.model_dump(by_alias=True))
+
+    def to_json(self) -> str:
+        """Returns the JSON representation of the model using alias"""
+        # TODO: pydantic v2: use .model_dump_json(by_alias=True, exclude_unset=True) instead
+        return json.dumps(self.to_dict())
+
+    @classmethod
+    def from_json(cls, json_str: str) -> Optional[Self]:
+        """Create an instance of CircularAllOfRef from a JSON string"""
+        return cls.from_dict(json.loads(json_str))
+
+    def to_dict(self) -> Dict[str, Any]:
+        """Return the dictionary representation of the model using alias.
+
+        This has the following differences from calling pydantic's
+        `self.model_dump(by_alias=True)`:
+
+        * `None` is only added to the output dict for nullable fields that
+          were set at model initialization. Other fields with value `None`
+          are ignored.
+        * Fields in `self.additional_properties` are added to the output dict.
+        """
+        excluded_fields: Set[str] = set([
+            "additional_properties",
+        ])
+
+        _dict = self.model_dump(
+            by_alias=True,
+            exclude=excluded_fields,
+            exclude_none=True,
+        )
+        # override the default output from pydantic by calling `to_dict()` of each item in second_circular_all_of_ref (list)
+        _items = []
+        if self.second_circular_all_of_ref:
+            for _item in self.second_circular_all_of_ref:
+                if _item:
+                    _items.append(_item.to_dict())
+            _dict['secondCircularAllOfRef'] = _items
+        # puts key-value pairs in additional_properties in the top level
+        if self.additional_properties is not None:
+            for _key, _value in self.additional_properties.items():
+                _dict[_key] = _value
+
+        return _dict
+
+    @classmethod
+    def from_dict(cls, obj: Optional[Dict[str, Any]]) -> Optional[Self]:
+        """Create an instance of CircularAllOfRef from a dict"""
+        if obj is None:
+            return None
+
+        if not isinstance(obj, dict):
+            return cls.model_validate(obj)
+
+        _obj = cls.model_validate({
+            "_name": obj.get("_name"),
+            "secondCircularAllOfRef": [SecondCircularAllOfRef.from_dict(_item) for _item in obj["secondCircularAllOfRef"]] if obj.get("secondCircularAllOfRef") is not None else None
+        })
+        # store additional fields in additional_properties
+        for _key in obj.keys():
+            if _key not in cls.__properties:
+                _obj.additional_properties[_key] = obj.get(_key)
+
+        return _obj
+
+from petstore_api.models.second_circular_all_of_ref import SecondCircularAllOfRef
+# TODO: Rewrite to not use raise_errors
+CircularAllOfRef.model_rebuild(raise_errors=False)
+

samples/openapi3/client/petstore/python/petstore_api/models/second_circular_all_of_ref.py

@@ -0,0 +1,112 @@
+# coding: utf-8
+
+"""
+    OpenAPI Petstore
+
+    This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+
+    The version of the OpenAPI document: 1.0.0
+    Generated by OpenAPI Generator (https://openapi-generator.tech)
+
+    Do not edit the class manually.
+"""  # noqa: E501
+
+
+from __future__ import annotations
+import pprint
+import re  # noqa: F401
+import json
+
+from pydantic import BaseModel, ConfigDict, Field, StrictStr
+from typing import Any, ClassVar, Dict, List, Optional
+from typing import Optional, Set
+from typing_extensions import Self
+
+class SecondCircularAllOfRef(BaseModel):
+    """
+    SecondCircularAllOfRef
+    """ # noqa: E501
+    name: Optional[StrictStr] = Field(default=None, alias="_name")
+    circular_all_of_ref: Optional[List[CircularAllOfRef]] = Field(default=None, alias="circularAllOfRef")
+    additional_properties: Dict[str, Any] = {}
+    __properties: ClassVar[List[str]] = ["_name", "circularAllOfRef"]
+
+    model_config = ConfigDict(
+        populate_by_name=True,
+        validate_assignment=True,
+        protected_namespaces=(),
+    )
+
+
+    def to_str(self) -> str:
+        """Returns the string representation of the model using alias"""
+        return pprint.pformat(self.model_dump(by_alias=True))
+
+    def to_json(self) -> str:
+        """Returns the JSON representation of the model using alias"""
+        # TODO: pydantic v2: use .model_dump_json(by_alias=True, exclude_unset=True) instead
+        return json.dumps(self.to_dict())
+
+    @classmethod
+    def from_json(cls, json_str: str) -> Optional[Self]:
+        """Create an instance of SecondCircularAllOfRef from a JSON string"""
+        return cls.from_dict(json.loads(json_str))
+
+    def to_dict(self) -> Dict[str, Any]:
+        """Return the dictionary representation of the model using alias.
+
+        This has the following differences from calling pydantic's
+        `self.model_dump(by_alias=True)`:
+
+        * `None` is only added to the output dict for nullable fields that
+          were set at model initialization. Other fields with value `None`
+          are ignored.
+        * Fields in `self.additional_properties` are added to the output dict.
+        """
+        excluded_fields: Set[str] = set([
+            "additional_properties",
+        ])
+
+        _dict = self.model_dump(
+            by_alias=True,
+            exclude=excluded_fields,
+            exclude_none=True,
+        )
+        # override the default output from pydantic by calling `to_dict()` of each item in circular_all_of_ref (list)
+        _items = []
+        if self.circular_all_of_ref:
+            for _item in self.circular_all_of_ref:
+                if _item:
+                    _items.append(_item.to_dict())
+            _dict['circularAllOfRef'] = _items
+        # puts key-value pairs in additional_properties in the top level
+        if self.additional_properties is not None:
+            for _key, _value in self.additional_properties.items():
+                _dict[_key] = _value
+
+        return _dict
+
+    @classmethod
+    def from_dict(cls, obj: Optional[Dict[str, Any]]) -> Optional[Self]:
+        """Create an instance of SecondCircularAllOfRef from a dict"""
+        if obj is None:
+            return None
+
+        if not isinstance(obj, dict):
+            return cls.model_validate(obj)
+
+        _obj = cls.model_validate({
+            "_name": obj.get("_name"),
+            "circularAllOfRef": [CircularAllOfRef.from_dict(_item) for _item in obj["circularAllOfRef"]] if obj.get("circularAllOfRef") is not None else None
+        })
+        # store additional fields in additional_properties
+        for _key in obj.keys():
+            if _key not in cls.__properties:
+                _obj.additional_properties[_key] = obj.get(_key)
+
+        return _obj
+
+from petstore_api.models.circular_all_of_ref import CircularAllOfRef
+# TODO: Rewrite to not use raise_errors
+SecondCircularAllOfRef.model_rebuild(raise_errors=False)
+

samples/openapi3/client/petstore/python/test/test_all_of_super_model.py

@@ -0,0 +1,51 @@
+# coding: utf-8
+
+"""
+    OpenAPI Petstore
+
+    This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+
+    The version of the OpenAPI document: 1.0.0
+    Generated by OpenAPI Generator (https://openapi-generator.tech)
+
+    Do not edit the class manually.
+"""  # noqa: E501
+
+
+import unittest
+
+from petstore_api.models.all_of_super_model import AllOfSuperModel
+
+class TestAllOfSuperModel(unittest.TestCase):
+    """AllOfSuperModel unit test stubs"""
+
+    def setUp(self):
+        pass
+
+    def tearDown(self):
+        pass
+
+    def make_instance(self, include_optional) -> AllOfSuperModel:
+        """Test AllOfSuperModel
+            include_option is a boolean, when False only required
+            params are included, when True both required and
+            optional params are included """
+        # uncomment below to create an instance of `AllOfSuperModel`
+        """
+        model = AllOfSuperModel()
+        if include_optional:
+            return AllOfSuperModel(
+                name = ''
+            )
+        else:
+            return AllOfSuperModel(
+        )
+        """
+
+    def testAllOfSuperModel(self):
+        """Test AllOfSuperModel"""
+        # inst_req_only = self.make_instance(include_optional=False)
+        # inst_req_and_optional = self.make_instance(include_optional=True)
+
+if __name__ == '__main__':
+    unittest.main()

samples/openapi3/client/petstore/python/test/test_circular_all_of_ref.py

@@ -0,0 +1,60 @@
+# coding: utf-8
+
+"""
+    OpenAPI Petstore
+
+    This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+
+    The version of the OpenAPI document: 1.0.0
+    Generated by OpenAPI Generator (https://openapi-generator.tech)
+
+    Do not edit the class manually.
+"""  # noqa: E501
+
+
+import unittest
+
+from petstore_api.models.circular_all_of_ref import CircularAllOfRef
+
+class TestCircularAllOfRef(unittest.TestCase):
+    """CircularAllOfRef unit test stubs"""
+
+    def setUp(self):
+        pass
+
+    def tearDown(self):
+        pass
+
+    def make_instance(self, include_optional) -> CircularAllOfRef:
+        """Test CircularAllOfRef
+            include_option is a boolean, when False only required
+            params are included, when True both required and
+            optional params are included """
+        # uncomment below to create an instance of `CircularAllOfRef`
+        """
+        model = CircularAllOfRef()
+        if include_optional:
+            return CircularAllOfRef(
+                second_circular_all_of_ref = [
+                    petstore_api.models.second_circular_all_of_ref.SecondCircularAllOfRef(
+                        circular_all_of_ref = [
+                            petstore_api.models.circular_all_of_ref.CircularAllOfRef(
+                                second_circular_all_of_ref = [
+                                    petstore_api.models.second_circular_all_of_ref.SecondCircularAllOfRef()
+                                    ], )
+                            ], )
+                    ],
+                name = ''
+            )
+        else:
+            return CircularAllOfRef(
+        )
+        """
+
+    def testCircularAllOfRef(self):
+        """Test CircularAllOfRef"""
+        # inst_req_only = self.make_instance(include_optional=False)
+        # inst_req_and_optional = self.make_instance(include_optional=True)
+
+if __name__ == '__main__':
+    unittest.main()

samples/openapi3/client/petstore/python/test/test_second_circular_all_of_ref.py

@@ -0,0 +1,57 @@
+# coding: utf-8
+
+"""
+    OpenAPI Petstore
+
+    This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+
+    The version of the OpenAPI document: 1.0.0
+    Generated by OpenAPI Generator (https://openapi-generator.tech)
+
+    Do not edit the class manually.
+"""  # noqa: E501
+
+
+import unittest
+
+from petstore_api.models.second_circular_all_of_ref import SecondCircularAllOfRef
+
+class TestSecondCircularAllOfRef(unittest.TestCase):
+    """SecondCircularAllOfRef unit test stubs"""
+
+    def setUp(self):
+        pass
+
+    def tearDown(self):
+        pass
+
+    def make_instance(self, include_optional) -> SecondCircularAllOfRef:
+        """Test SecondCircularAllOfRef
+            include_option is a boolean, when False only required
+            params are included, when True both required and
+            optional params are included """
+        # uncomment below to create an instance of `SecondCircularAllOfRef`
+        """
+        model = SecondCircularAllOfRef()
+        if include_optional:
+            return SecondCircularAllOfRef(
+                circular_all_of_ref = [
+                    petstore_api.models.circular_all_of_ref.CircularAllOfRef(
+                        second_circular_all_of_ref = [
+                            petstore_api.models.second_circular_all_of_ref.SecondCircularAllOfRef()
+                            ], )
+                    ],
+                name = ''
+            )
+        else:
+            return SecondCircularAllOfRef(
+        )
+        """
+
+    def testSecondCircularAllOfRef(self):
+        """Test SecondCircularAllOfRef"""
+        # inst_req_only = self.make_instance(include_optional=False)
+        # inst_req_and_optional = self.make_instance(include_optional=True)
+
+if __name__ == '__main__':
+    unittest.main()

samples/openapi3/client/petstore/python/tests/test_model.py

@@ -619,6 +619,16 @@ class ModelTests(unittest.TestCase):
         assert model is not None
         self.assertEqual(model.to_json(), '{"skill": "none", "type": "tiger", "info": {"name": "creature info"}}')
 
+    def test_allof_circular_imports(self):
+        # for issue 18271
+        model_a = petstore_api.models.circular_all_of_ref.CircularAllOfRef.from_json('{"_name": "nameA", "second_circular_all_of_ref": {"name": "nameB"}}')
+        model_b = petstore_api.models.second_circular_all_of_ref.SecondCircularAllOfRef.from_json('{"_name": "nameB", "circular_all_of_ref": {"name": "nameA"}}')
+        # shouldn't throw ImportError
+        assert model_a is not None
+        assert model_b is not None
+        self.assertEqual(model_a.to_json(), '{"_name": "nameA", "second_circular_all_of_ref": {"name": "nameB"}}')
+        self.assertEqual(model_b.to_json(), '{"_name": "nameB", "circular_all_of_ref": {"name": "nameA"}}')
+
 
 class TestdditionalPropertiesAnyType(unittest.TestCase):
     def test_additional_properties(self):