[python] Fix Circular imports on inherited discriminators.

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractPythonCodegen.java

@@ -867,6 +867,7 @@ private ModelsMap postProcessModelsMap(ModelsMap objs) {
         TreeSet<String> datetimeImports = new TreeSet<>();
         TreeSet<String> modelImports = new TreeSet<>();
         TreeSet<String> postponedModelImports = new TreeSet<>();
+        TreeSet<String> discriminatorModelImports = new TreeSet<>();
 
         for (ModelMap m : objs.getModels()) {
             TreeSet<String> exampleImports = new TreeSet<>();
@@ -929,7 +930,7 @@ private ModelsMap postProcessModelsMap(ModelsMap objs) {
                     typingImports.add("Union");
                     Set<CodegenDiscriminator.MappedModel> discriminator = model.getDiscriminator().getMappedModels();
                     for (CodegenDiscriminator.MappedModel mappedModel : discriminator) {
-                        postponedModelImports.add(mappedModel.getMappingName());
+                        discriminatorModelImports.add(mappedModel.getMappingName());
                     }
                 }
             }
@@ -1035,6 +1036,19 @@ private ModelsMap postProcessModelsMap(ModelsMap objs) {
 
                 model.getVendorExtensions().putIfAbsent("x-py-postponed-model-imports", modelsToImport);
             }
+
+            if (!discriminatorModelImports.isEmpty()) {
+                Set<String> modelsToImport = new TreeSet<>();
+                for (String modelImport : discriminatorModelImports) {
+                    if (modelImport.equals(model.classname)) {
+                        // skip self import
+                        continue;
+                    }
+                    modelsToImport.add("globals()[\"" + modelImport + "\"] = importlib.import_module(\"" + packageName + ".models." + underscore(modelImport) + "\")." + modelImport);
+                }
+
+                model.discriminator.getVendorExtensions().putIfAbsent("x-py-discriminator-model-imports", modelsToImport);
+            }
         }
 
         return objs;

modules/openapi-generator/src/main/resources/python/model_generic.mustache

@@ -2,6 +2,7 @@ from __future__ import annotations
 import pprint
 import re  # noqa: F401
 import json
+import importlib
 
 {{#vendorExtensions.x-py-datetime-imports}}{{#-first}}from datetime import{{/-first}} {{{.}}}{{^-last}},{{/-last}}{{/vendorExtensions.x-py-datetime-imports}}
 {{#vendorExtensions.x-py-typing-imports}}{{#-first}}from typing import{{/-first}} {{{.}}}{{^-last}},{{/-last}}{{/vendorExtensions.x-py-typing-imports}}
@@ -93,16 +94,28 @@ class {{classname}}({{#parent}}{{{.}}}{{/parent}}{{^parent}}BaseModel{{/parent}}
     __discriminator_property_name: ClassVar[List[str]] = '{{discriminator.propertyBaseName}}'
 
     # discriminator mappings
-    __discriminator_value_class_map: ClassVar[Dict[str, str]] = {
-        {{#mappedModels}}'{{{mappingName}}}': '{{{modelName}}}'{{^-last}},{{/-last}}{{/mappedModels}}
-    }
+    __discriminator_value_class_map: ClassVar[Union[Dict[str, str], None]] = None
+
+    @classmethod
+    def _get_discriminator_value_class_map(cls) -> ClassVar[Dict[str, str]]:
+        if cls.__discriminator_value_class_map == None:
+            # Prevent circular imports caused by mutually referencing classes
+            {{#vendorExtensions.x-py-discriminator-model-imports}}
+            {{{.}}}
+            {{/vendorExtensions.x-py-discriminator-model-imports}}
+
+            cls.__discriminator_value_class_map = {
+                {{#mappedModels}}'{{{mappingName}}}': '{{{modelName}}}'{{^-last}},{{/-last}}{{/mappedModels}}
+            }
+        return cls.__discriminator_value_class_map
 
     @classmethod
     def get_discriminator_value(cls, obj: dict) -> str:
         """Returns the discriminator value (object type) of the data"""
+
         discriminator_value = obj[cls.__discriminator_property_name]
         if discriminator_value:
-            return cls.__discriminator_value_class_map.get(discriminator_value)
+            return cls._get_discriminator_value_class_map().get(discriminator_value)
         else:
             return None
 
@@ -250,7 +263,7 @@ class {{classname}}({{#parent}}{{{.}}}{{/parent}}{{^parent}}BaseModel{{/parent}}
         else:
             raise ValueError("{{{classname}}} failed to lookup discriminator value from " +
                              json.dumps(obj) + ". Discriminator property name: " + cls.__discriminator_property_name +
-                             ", mapping: " + json.dumps(cls.__discriminator_value_class_map))
+                             ", mapping: " + json.dumps(cls._get_discriminator_value_class_map()))
         {{/discriminator}}
         {{/hasChildren}}
         {{^hasChildren}}

samples/client/echo_api/python-disallowAdditionalPropertiesIfNotPresent-true/openapi_client/models/bird.py

@@ -17,6 +17,7 @@
 import pprint
 import re  # noqa: F401
 import json
+import importlib
 
 
 from typing import Optional

samples/client/echo_api/python-disallowAdditionalPropertiesIfNotPresent-true/openapi_client/models/category.py

@@ -17,6 +17,7 @@
 import pprint
 import re  # noqa: F401
 import json
+import importlib
 
 
 from typing import Optional

samples/client/echo_api/python-disallowAdditionalPropertiesIfNotPresent-true/openapi_client/models/data_query.py

@@ -17,6 +17,7 @@
 import pprint
 import re  # noqa: F401
 import json
+import importlib
 
 from datetime import datetime
 from typing import Optional

samples/client/echo_api/python-disallowAdditionalPropertiesIfNotPresent-true/openapi_client/models/default_value.py

@@ -17,6 +17,7 @@
 import pprint
 import re  # noqa: F401
 import json
+import importlib
 
 
 from typing import List, Optional

samples/client/echo_api/python-disallowAdditionalPropertiesIfNotPresent-true/openapi_client/models/number_properties_only.py

@@ -17,6 +17,7 @@
 import pprint
 import re  # noqa: F401
 import json
+import importlib
 
 
 from typing import Optional, Union

samples/client/echo_api/python-disallowAdditionalPropertiesIfNotPresent-true/openapi_client/models/pet.py

@@ -17,6 +17,7 @@
 import pprint
 import re  # noqa: F401
 import json
+import importlib
 
 
 from typing import List, Optional

samples/client/echo_api/python-disallowAdditionalPropertiesIfNotPresent-true/openapi_client/models/query.py

@@ -17,6 +17,7 @@
 import pprint
 import re  # noqa: F401
 import json
+import importlib
 
 
 from typing import List, Optional

samples/client/echo_api/python-disallowAdditionalPropertiesIfNotPresent-true/openapi_client/models/tag.py

@@ -17,6 +17,7 @@
 import pprint
 import re  # noqa: F401
 import json
+import importlib
 
 
 from typing import Optional

samples/client/echo_api/python-disallowAdditionalPropertiesIfNotPresent-true/openapi_client/models/test_query_style_deep_object_explode_true_object_all_of_query_object_parameter.py

@@ -17,6 +17,7 @@
 import pprint
 import re  # noqa: F401
 import json
+import importlib
 
 
 from typing import Optional

samples/client/echo_api/python-disallowAdditionalPropertiesIfNotPresent-true/openapi_client/models/test_query_style_form_explode_true_array_string_query_object_parameter.py

@@ -17,6 +17,7 @@
 import pprint
 import re  # noqa: F401
 import json
+import importlib
 
 
 from typing import List, Optional

samples/client/echo_api/python/openapi_client/models/bird.py

@@ -17,6 +17,7 @@
 import pprint
 import re  # noqa: F401
 import json
+import importlib
 
 
 from typing import Optional

samples/client/echo_api/python/openapi_client/models/category.py

@@ -17,6 +17,7 @@
 import pprint
 import re  # noqa: F401
 import json
+import importlib
 
 
 from typing import Optional

samples/client/echo_api/python/openapi_client/models/data_query.py

@@ -17,6 +17,7 @@
 import pprint
 import re  # noqa: F401
 import json
+import importlib
 
 from datetime import datetime
 from typing import Optional

samples/client/echo_api/python/openapi_client/models/default_value.py

@@ -17,6 +17,7 @@
 import pprint
 import re  # noqa: F401
 import json
+import importlib
 
 
 from typing import List, Optional

samples/client/echo_api/python/openapi_client/models/number_properties_only.py

@@ -17,6 +17,7 @@
 import pprint
 import re  # noqa: F401
 import json
+import importlib
 
 
 from typing import Optional, Union

samples/client/echo_api/python/openapi_client/models/pet.py

@@ -17,6 +17,7 @@
 import pprint
 import re  # noqa: F401
 import json
+import importlib
 
 
 from typing import List, Optional

samples/client/echo_api/python/openapi_client/models/query.py

@@ -17,6 +17,7 @@
 import pprint
 import re  # noqa: F401
 import json
+import importlib
 
 
 from typing import List, Optional

samples/client/echo_api/python/openapi_client/models/tag.py

@@ -17,6 +17,7 @@
 import pprint
 import re  # noqa: F401
 import json
+import importlib
 
 
 from typing import Optional

samples/client/echo_api/python/openapi_client/models/test_query_style_deep_object_explode_true_object_all_of_query_object_parameter.py

@@ -17,6 +17,7 @@
 import pprint
 import re  # noqa: F401
 import json
+import importlib
 
 
 from typing import Optional

samples/client/echo_api/python/openapi_client/models/test_query_style_form_explode_true_array_string_query_object_parameter.py

@@ -17,6 +17,7 @@
 import pprint
 import re  # noqa: F401
 import json
+import importlib
 
 
 from typing import List, Optional

samples/openapi3/client/petstore/python-aiohttp/petstore_api/models/additional_properties_any_type.py

@@ -16,6 +16,7 @@
 import pprint
 import re  # noqa: F401
 import json
+import importlib
 
 
 from typing import Optional

samples/openapi3/client/petstore/python-aiohttp/petstore_api/models/additional_properties_class.py

@@ -16,6 +16,7 @@
 import pprint
 import re  # noqa: F401
 import json
+import importlib
 
 
 from typing import Dict, Optional

samples/openapi3/client/petstore/python-aiohttp/petstore_api/models/additional_properties_object.py

@@ -16,6 +16,7 @@
 import pprint
 import re  # noqa: F401
 import json
+import importlib
 
 
 from typing import Optional

samples/openapi3/client/petstore/python-aiohttp/petstore_api/models/additional_properties_with_description_only.py

@@ -16,6 +16,7 @@
 import pprint
 import re  # noqa: F401
 import json
+import importlib
 
 
 from typing import Optional

samples/openapi3/client/petstore/python-aiohttp/petstore_api/models/all_of_with_single_ref.py

@@ -16,6 +16,7 @@
 import pprint
 import re  # noqa: F401
 import json
+import importlib
 
 
 from typing import Optional

samples/openapi3/client/petstore/python-aiohttp/petstore_api/models/animal.py

@@ -16,6 +16,7 @@
 import pprint
 import re  # noqa: F401
 import json
+import importlib
 
 
 from typing import Optional, Union
@@ -45,16 +46,27 @@ class Animal(BaseModel):
     __discriminator_property_name: ClassVar[List[str]] = 'className'
 
     # discriminator mappings
-    __discriminator_value_class_map: ClassVar[Dict[str, str]] = {
-        'Cat': 'Cat','Dog': 'Dog'
-    }
+    __discriminator_value_class_map: ClassVar[Union[Dict[str, str], None]] = None
+
+    @classmethod
+    def _get_discriminator_value_class_map(cls) -> ClassVar[Dict[str, str]]:
+        if cls.__discriminator_value_class_map == None:
+            # Prevent circular imports caused by mutually referencing classes
+            globals()["Cat"] = importlib.import_module("petstore_api.models.cat").Cat
+            globals()["Dog"] = importlib.import_module("petstore_api.models.dog").Dog
+
+            cls.__discriminator_value_class_map = {
+                'Cat': 'Cat','Dog': 'Dog'
+            }
+        return cls.__discriminator_value_class_map
 
     @classmethod
     def get_discriminator_value(cls, obj: dict) -> str:
         """Returns the discriminator value (object type) of the data"""
+
         discriminator_value = obj[cls.__discriminator_property_name]
         if discriminator_value:
-            return cls.__discriminator_value_class_map.get(discriminator_value)
+            return cls._get_discriminator_value_class_map().get(discriminator_value)
         else:
             return None
 
@@ -101,13 +113,6 @@ def from_dict(cls, obj: dict) -> Union[Self, Self]:
         else:
             raise ValueError("Animal failed to lookup discriminator value from " +
                              json.dumps(obj) + ". Discriminator property name: " + cls.__discriminator_property_name +
-                             ", mapping: " + json.dumps(cls.__discriminator_value_class_map))
-
-from petstore_api.models.cat import Cat
-from petstore_api.models.dog import Dog
-from typing import TYPE_CHECKING
-if TYPE_CHECKING:
-    # TODO: pydantic v2
-    # Animal.model_rebuild()
-    pass
+                             ", mapping: " + json.dumps(cls._get_discriminator_value_class_map()))
+
 

samples/openapi3/client/petstore/python-aiohttp/petstore_api/models/api_response.py

@@ -16,6 +16,7 @@
 import pprint
 import re  # noqa: F401
 import json
+import importlib
 
 
 from typing import Optional

samples/openapi3/client/petstore/python-aiohttp/petstore_api/models/array_of_array_of_model.py

@@ -16,6 +16,7 @@
 import pprint
 import re  # noqa: F401
 import json
+import importlib
 
 
 from typing import List, Optional

samples/openapi3/client/petstore/python-aiohttp/petstore_api/models/array_of_array_of_number_only.py

@@ -16,6 +16,7 @@
 import pprint
 import re  # noqa: F401
 import json
+import importlib
 
 
 from typing import List, Optional

samples/openapi3/client/petstore/python-aiohttp/petstore_api/models/array_of_number_only.py

@@ -16,6 +16,7 @@
 import pprint
 import re  # noqa: F401
 import json
+import importlib
 
 
 from typing import List, Optional

samples/openapi3/client/petstore/python-aiohttp/petstore_api/models/array_test.py

@@ -16,6 +16,7 @@
 import pprint
 import re  # noqa: F401
 import json
+import importlib
 
 
 from typing import List, Optional

samples/openapi3/client/petstore/python-aiohttp/petstore_api/models/basque_pig.py

@@ -16,6 +16,7 @@
 import pprint
 import re  # noqa: F401
 import json
+import importlib
 
 
 

samples/openapi3/client/petstore/python-aiohttp/petstore_api/models/capitalization.py

@@ -16,6 +16,7 @@
 import pprint
 import re  # noqa: F401
 import json
+import importlib
 
 
 from typing import Optional