Better pydantic support in python fast api server

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

@@ -139,7 +139,18 @@ public PythonFastAPIServerCodegen() {
                 .defaultValue(DEFAULT_SOURCE_FOLDER));
         cliOptions.add(new CliOption(CodegenConstants.FASTAPI_IMPLEMENTATION_PACKAGE, "python package name for the implementation code (convention: snake_case).")
                 .defaultValue(DEFAULT_PACKAGE_NAME.concat(".impl")));
-
+        // option to change how we process + set the data in the 'additionalProperties' keyword.
+        CliOption disallowAdditionalPropertiesIfNotPresentOpt = CliOption.newBoolean(
+                CodegenConstants.DISALLOW_ADDITIONAL_PROPERTIES_IF_NOT_PRESENT,
+                CodegenConstants.DISALLOW_ADDITIONAL_PROPERTIES_IF_NOT_PRESENT_DESC).defaultValue(Boolean.TRUE.toString());
+        Map<String, String> disallowAdditionalPropertiesIfNotPresentOpts = new HashMap<>();
+        disallowAdditionalPropertiesIfNotPresentOpts.put("false",
+                "The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.");
+        disallowAdditionalPropertiesIfNotPresentOpts.put("true",
+                "Keep the old (incorrect) behaviour that 'additionalProperties' is set to false by default.");
+        disallowAdditionalPropertiesIfNotPresentOpt.setEnum(disallowAdditionalPropertiesIfNotPresentOpts);
+        cliOptions.add(disallowAdditionalPropertiesIfNotPresentOpt);
+        this.setDisallowAdditionalPropertiesIfNotPresent(true);
     }
 
     @Override
@@ -322,5 +333,7 @@ public void postProcess() {
     }
 
     @Override
-    public String generatorLanguageVersion() { return "3.7"; };
+    public String generatorLanguageVersion() {
+        return "3.7";
+    }
 }

modules/openapi-generator/src/main/resources/python-fastapi/model.mustache

@@ -1,76 +1,14 @@
 # coding: utf-8
 
-from __future__ import annotations
-from datetime import date, datetime  # noqa: F401
-
-import re  # noqa: F401
-from typing import Any, Dict, List, Optional  # noqa: F401
-
-from pydantic import AnyUrl, BaseModel, EmailStr, Field, validator  # noqa: F401
-{{#models}}
-{{#model}}
-{{#pyImports}}
-{{import}}
-{{/pyImports}}
-{{/model}}
-{{/models}}
-
+{{>partial_header}}
 
 {{#models}}
 {{#model}}
-class {{classname}}(BaseModel):
-    """NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
-
-    Do not edit the class manually.
-
-    {{classname}} - a model defined in OpenAPI
-
-    {{#vars}}
-        {{name}}: The {{name}} of this {{classname}}{{^required}} [Optional]{{/required}}.
-    {{/vars}}
-    """
-
-{{#vars}}
-    {{name}}: {{#required}}{{>model_field_type}}{{/required}}{{^required}}Optional[{{>model_field_type}}]{{/required}} = Field(alias="{{baseName}}"{{^required}}, default=None{{/required}})
-{{/vars}}
-{{#vars}}
-{{#maximum}}
-
-    @validator("{{name}}")
-    def {{name}}_max(cls, value):
-        assert value <= {{maximum}}
-        return value
-{{/maximum}}
-{{#minimum}}
-
-    @validator("{{name}}")
-    def {{name}}_min(cls, value):
-        assert value >= {{minimum}}
-        return value
-{{/minimum}}
-{{#minLength}}
-
-    @validator("{{name}}")
-    def {{name}}_min_length(cls, value):
-        assert len(value) >= {{minLength}}
-        return value
-{{/minLength}}
-{{#maxLength}}
-
-    @validator("{{name}}")
-    def {{name}}_max_length(cls, value):
-        assert len(value) <= {{maxLength}}
-        return value
-{{/maxLength}}
-{{#pattern}}
-
-    @validator("{{name}}")
-    def {{name}}_pattern(cls, value):
-        assert value is not None and re.match(r"{{pattern}}", value)
-        return value
-{{/pattern}}
-{{/vars}}
+{{#isEnum}}
+{{>model_enum}}
+{{/isEnum}}
+{{^isEnum}}
+{{#oneOf}}{{#-first}}{{>model_oneof}}{{/-first}}{{/oneOf}}{{^oneOf}}{{#anyOf}}{{#-first}}{{>model_anyof}}{{/-first}}{{/anyOf}}{{^anyOf}}{{>model_generic}}{{/anyOf}}{{/oneOf}}
+{{/isEnum}}
 {{/model}}
-{{/models}}
-
-{{classname}}.update_forward_refs()
+{{/models}}

modules/openapi-generator/src/main/resources/python-fastapi/model_anyof.mustache

@@ -0,0 +1,180 @@
+from __future__ import annotations
+from inspect import getfullargspec
+import json
+import pprint
+import re  # noqa: F401
+{{#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}}
+{{#vendorExtensions.x-py-pydantic-imports}}{{#-first}}from pydantic import{{/-first}} {{{.}}}{{^-last}},{{/-last}}{{/vendorExtensions.x-py-pydantic-imports}}
+{{#vendorExtensions.x-py-model-imports}}
+{{{.}}}
+{{/vendorExtensions.x-py-model-imports}}
+from typing import Union, Any, List, TYPE_CHECKING
+from pydantic import StrictStr, Field
+
+{{#lambda.uppercase}}{{{classname}}}{{/lambda.uppercase}}_ANY_OF_SCHEMAS = [{{#anyOf}}"{{.}}"{{^-last}}, {{/-last}}{{/anyOf}}]
+
+class {{classname}}({{#parent}}{{{.}}}{{/parent}}{{^parent}}BaseModel{{/parent}}):
+    """
+    {{{description}}}{{^description}}{{{classname}}}{{/description}}
+    """
+
+{{#composedSchemas.anyOf}}
+    # data type: {{{dataType}}}
+    {{vendorExtensions.x-py-name}}: {{{vendorExtensions.x-py-typing}}}
+{{/composedSchemas.anyOf}}
+    if TYPE_CHECKING:
+        actual_instance: Union[{{#anyOf}}{{{.}}}{{^-last}}, {{/-last}}{{/anyOf}}]
+    else:
+        actual_instance: Any
+    any_of_schemas: List[str] = Field({{#lambda.uppercase}}{{{classname}}}{{/lambda.uppercase}}_ANY_OF_SCHEMAS, const=True)
+
+    class Config:
+        validate_assignment = True
+{{#discriminator}}
+
+    discriminator_value_class_map = {
+{{#children}}
+        '{{^vendorExtensions.x-discriminator-value}}{{name}}{{/vendorExtensions.x-discriminator-value}}{{#vendorExtensions.x-discriminator-value}}{{{vendorExtensions.x-discriminator-value}}}{{/vendorExtensions.x-discriminator-value}}': '{{{classname}}}'{{^-last}},{{/-last}}
+{{/children}}
+    }
+{{/discriminator}}
+
+    def __init__(self, *args, **kwargs):
+        if args:
+            if len(args) > 1:
+                raise ValueError("If a position argument is used, only 1 is allowed to set `actual_instance`")
+            if kwargs:
+                raise ValueError("If a position argument is used, keyword arguments cannot be used.")
+            super().__init__(actual_instance=args[0])
+        else:
+            super().__init__(**kwargs)
+
+    @validator('actual_instance')
+    def actual_instance_must_validate_anyof(cls, v):
+        {{#isNullable}}
+        if v is None:
+            return v
+
+        {{/isNullable}}
+        instance = {{{classname}}}.construct()
+        error_messages = []
+        {{#composedSchemas.anyOf}}
+        # validate data type: {{{dataType}}}
+        {{#isContainer}}
+        try:
+            instance.{{vendorExtensions.x-py-name}} = v
+            return v
+        except (ValidationError, ValueError) as e:
+            error_messages.append(str(e))
+        {{/isContainer}}
+        {{^isContainer}}
+        {{#isPrimitiveType}}
+        try:
+            instance.{{vendorExtensions.x-py-name}} = v
+            return v
+        except (ValidationError, ValueError) as e:
+            error_messages.append(str(e))
+        {{/isPrimitiveType}}
+        {{^isPrimitiveType}}
+        if not isinstance(v, {{{dataType}}}):
+            error_messages.append(f"Error! Input type `{type(v)}` is not `{{{dataType}}}`")
+        else:
+            return v
+
+        {{/isPrimitiveType}}
+        {{/isContainer}}
+        {{/composedSchemas.anyOf}}
+        if error_messages:
+            # no match
+            raise ValueError("No match found when setting the actual_instance in {{{classname}}} with anyOf schemas: {{#anyOf}}{{{.}}}{{^-last}}, {{/-last}}{{/anyOf}}. Details: " + ", ".join(error_messages))
+        else:
+            return v
+
+    @classmethod
+    def from_dict(cls, obj: dict) -> {{{classname}}}:
+        return cls.from_json(json.dumps(obj))
+
+    @classmethod
+    def from_json(cls, json_str: str) -> {{{classname}}}:
+        """Returns the object represented by the json string"""
+        instance = {{{classname}}}.construct()
+        {{#isNullable}}
+        if json_str is None:
+            return instance
+
+        {{/isNullable}}
+        error_messages = []
+        {{#composedSchemas.anyOf}}
+        {{#isContainer}}
+        # deserialize data into {{{dataType}}}
+        try:
+            # validation
+            instance.{{vendorExtensions.x-py-name}} = json.loads(json_str)
+            # assign value to actual_instance
+            instance.actual_instance = instance.{{vendorExtensions.x-py-name}}
+            return instance
+        except (ValidationError, ValueError) as e:
+            error_messages.append(str(e))
+        {{/isContainer}}
+        {{^isContainer}}
+        {{#isPrimitiveType}}
+        # deserialize data into {{{dataType}}}
+        try:
+            # validation
+            instance.{{vendorExtensions.x-py-name}} = json.loads(json_str)
+            # assign value to actual_instance
+            instance.actual_instance = instance.{{vendorExtensions.x-py-name}}
+            return instance
+        except (ValidationError, ValueError) as e:
+            error_messages.append(str(e))
+        {{/isPrimitiveType}}
+        {{^isPrimitiveType}}
+        # {{vendorExtensions.x-py-name}}: {{{vendorExtensions.x-py-typing}}}
+        try:
+            instance.actual_instance = {{{dataType}}}.from_json(json_str)
+            return instance
+        except (ValidationError, ValueError) as e:
+             error_messages.append(str(e))
+        {{/isPrimitiveType}}
+        {{/isContainer}}
+        {{/composedSchemas.anyOf}}
+
+        if error_messages:
+            # no match
+            raise ValueError("No match found when deserializing the JSON string into {{{classname}}} with anyOf schemas: {{#anyOf}}{{{.}}}{{^-last}}, {{/-last}}{{/anyOf}}. Details: " + ", ".join(error_messages))
+        else:
+            return instance
+
+    def to_json(self) -> str:
+        """Returns the JSON representation of the actual instance"""
+        if self.actual_instance is None:
+            return "null"
+
+        to_json = getattr(self.actual_instance, "to_json", None)
+        if callable(to_json):
+            return self.actual_instance.to_json()
+        else:
+            return json.dumps(self.actual_instance)
+
+    def to_dict(self) -> dict:
+        """Returns the dict representation of the actual instance"""
+        if self.actual_instance is None:
+            return "null"
+
+        to_json = getattr(self.actual_instance, "to_json", None)
+        if callable(to_json):
+            return self.actual_instance.to_dict()
+        else:
+            return json.dumps(self.actual_instance)
+
+    def to_str(self) -> str:
+        """Returns the string representation of the actual instance"""
+        return pprint.pformat(self.dict())
+
+{{#vendorExtensions.x-py-postponed-model-imports.size}}
+{{#vendorExtensions.x-py-postponed-model-imports}}
+{{{.}}}
+{{/vendorExtensions.x-py-postponed-model-imports}}
+{{classname}}.update_forward_refs()
+{{/vendorExtensions.x-py-postponed-model-imports.size}}

modules/openapi-generator/src/main/resources/python-fastapi/model_doc.mustache

@@ -0,0 +1,33 @@
+{{#models}}{{#model}}# {{classname}}
+
+{{#description}}{{&description}}
+{{/description}}
+
+## Properties
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+{{#vars}}**{{name}}** | {{#isPrimitiveType}}**{{dataType}}**{{/isPrimitiveType}}{{^isPrimitiveType}}[**{{dataType}}**]({{complexType}}.md){{/isPrimitiveType}} | {{description}} | {{^required}}[optional] {{/required}}{{#isReadOnly}}[readonly] {{/isReadOnly}}{{#defaultValue}}[default to {{{.}}}]{{/defaultValue}}
+{{/vars}}
+
+{{^isEnum}}
+## Example
+
+```python
+from {{modelPackage}}.{{#lambda.snakecase}}{{classname}}{{/lambda.snakecase}} import {{classname}}
+
+# TODO update the JSON string below
+json = "{}"
+# create an instance of {{classname}} from a JSON string
+{{#lambda.snakecase}}{{classname}}{{/lambda.snakecase}}_instance = {{classname}}.from_json(json)
+# print the JSON string representation of the object
+print {{classname}}.to_json()
+
+# convert the object into a dict
+{{#lambda.snakecase}}{{classname}}{{/lambda.snakecase}}_dict = {{#lambda.snakecase}}{{classname}}{{/lambda.snakecase}}_instance.to_dict()
+# create an instance of {{classname}} from a dict
+{{#lambda.snakecase}}{{classname}}{{/lambda.snakecase}}_form_dict = {{#lambda.snakecase}}{{classname}}{{/lambda.snakecase}}.from_dict({{#lambda.snakecase}}{{classname}}{{/lambda.snakecase}}_dict)
+```
+{{/isEnum}}
+[[Back to Model list]](../README.md#documentation-for-models) [[Back to API list]](../README.md#documentation-for-api-endpoints) [[Back to README]](../README.md)
+
+{{/model}}{{/models}}

modules/openapi-generator/src/main/resources/python-fastapi/model_enum.mustache

@@ -0,0 +1,36 @@
+import json
+import pprint
+import re  # noqa: F401
+from aenum import Enum, no_arg
+{{#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}}
+{{#vendorExtensions.x-py-pydantic-imports}}{{#-first}}from pydantic import{{/-first}} {{{.}}}{{^-last}},{{/-last}}{{/vendorExtensions.x-py-pydantic-imports}}
+
+
+class {{classname}}({{vendorExtensions.x-py-enum-type}}, Enum):
+    """
+    {{{description}}}{{^description}}{{{classname}}}{{/description}}
+    """
+
+    """
+    allowed enum values
+    """
+{{#allowableValues}}
+    {{#enumVars}}
+    {{{name}}} = {{{value}}}
+    {{/enumVars}}
+
+    @classmethod
+    def from_json(cls, json_str: str) -> {{{classname}}}:
+        """Create an instance of {{classname}} from a JSON string"""
+        return {{classname}}(json.loads(json_str))
+
+    {{#defaultValue}}
+
+    #
+    @classmethod
+    def _missing_value_(cls, value):
+        if value is no_arg:
+            return cls.{{{.}}}
+    {{/defaultValue}}
+{{/allowableValues}}