chore: fix python generation issue for nested object (#770)

<!--
We appreciate the effort for this pull request but before that please
make sure you read the contribution guidelines, then fill out the blanks
below.

Please format the PR title appropriately based on the type of change:
  <type>[!]: <description>
Where <type> is one of: docs, chore, feat, fix, test, misc.
Add a '!' after the type for breaking changes (e.g. feat!: new breaking
feature).

**All third-party contributors acknowledge that any contributions they
provide will be made under the same open-source license that the
open-source project is provided under.**

Please enter each Issue number you are resolving in your PR after one of
the following words [Fixes, Closes, Resolves]. This will auto-link these
issues and close them when this PR is merged!
e.g.
Fixes #1
Closes #2
-->

# Fixes #
Added two fixes

- Empty to_dict generation for nested object. This was happening due to
`json-name` not getting propagated to nested objects
- reserved Keyword for nested property fix. Should use name instead of
baseName, sInce name has the updated value for reserved keyword like
_from for from.

Code generated of conversation v2 here
twilio/twilio-python#909

### Checklist
- [x] I acknowledge that all my contributions will be made under the
project's license
- [ ] Run `make test-docker`
- [ ] Verify affected language according to the code change:
- [ ] Generate [twilio-java](https://github.com/twilio/twilio-java) from
our [OpenAPI specification](https://github.com/twilio/twilio-oai) using
the [scripts/build_twilio_library.py](./scripts/build_twilio_library.py)
using `python scripts/build_twilio_library.py
path/to/twilio-oai/spec/yaml path/to/twilio-java -l java` and inspect
the diff
    - [ ] Run `make test` in `twilio-java`
    - [ ] Create a pull request in `twilio-java`
- [ ] Provide a link below to the pull request, this ensures that the
generated code has been verified
- [ ] I have made a material change to the repo (functionality, testing,
spelling, grammar)
- [ ] I have read the [Contribution
Guidelines](https://github.com/twilio/twilio-oai-generator/blob/main/CONTRIBUTING.md)
and my PR follows them
- [ ] I have titled the PR appropriately
- [ ] I have updated my branch with the main branch
- [ ] I have added tests that prove my fix is effective or that my
feature works
- [ ] I have added the necessary documentation about the functionality
in the appropriate .md file
- [ ] I have added inline documentation to the code I modified

If you have questions, please create a GitHub Issue in this repository.

Author: kridai

src/main/java/com/twilio/oai/api/PythonApiResourceBuilder.java

@@ -151,7 +151,17 @@ public ApiResourceBuilder updateResponseModel(Resolver<CodegenProperty> codegenP
                 .forEach(this::processModelVariables);
         }
 
-        modelTree.values().forEach(model -> model.setName(getModelName(model.getClassname())));
+        modelTree.values().forEach(model -> {
+            model.setName(getModelName(model.getClassname()));
+            // Set json-name for properties in nested models
+            model.getVars().forEach(property -> {
+                // Set json-name using baseName (original field name from spec) if it differs from name
+                String jsonName = (property.baseName != null && !property.baseName.equals(property.name))
+                    ? property.baseName
+                    : property.name;
+                property.vendorExtensions.put("json-name", jsonName);
+            });
+        });
         if (responseModel != null) {
             responseModel.getVars().forEach(variable -> {
                 if (variable.complexType != null && !variable.complexType.contains(ApplicationConstants.ENUM)) {

src/main/java/com/twilio/oai/resolver/python/PythonCodegenModelDataTypeResolver.java

@@ -41,16 +41,13 @@ public void setCodegenModel(CodegenModelResolver codegenModelResolver) {
      */
     @Override
     public CodegenProperty resolve(CodegenProperty property, ApiResourceBuilder apiResourceBuilder) {
-        property =  super.resolve(property, apiResourceBuilder);
+        property = super.resolve(property, apiResourceBuilder);
         CodegenModel codegenModel = apiResourceBuilder.getModel(property.dataType);
         if (codegenModel != null && !CodegenUtils.isPropertySchemaEnum(property)) {
-            // this is recursion as codegenModelResolver will again call PythonCodegenModelDataTypeResolver
             codegenModelResolver.resolve(codegenModel, apiResourceBuilder);
             apiResourceBuilder.addNestedModel(codegenModel);
-        } else {
-            super.resolve(property, apiResourceBuilder);
-            resolveProperty(property, apiResourceBuilder);
         }
+        resolveProperty(property, apiResourceBuilder);
         return property;
     }
 
@@ -61,6 +58,7 @@ public CodegenProperty resolve(CodegenProperty property, ApiResourceBuilder apiR
      */
     public void resolveResponseModel(CodegenProperty property, ApiResourceBuilder apiResourceBuilder) {
         super.resolve(property, apiResourceBuilder);
+        resolveProperty(property, apiResourceBuilder);
     }
 
     /**
@@ -74,19 +72,24 @@ protected void resolveProperty(CodegenProperty property, ApiResourceBuilder apiR
             property.name = "from_";
             property.vendorExtensions.put("json-name", "from");
         } else {
-            property.vendorExtensions.put("json-name", property.name);
+            // Use baseName (original field name from spec) as the json-name if it differs from name
+            // This handles cases where reserved word mappings have been applied
+            String jsonName = (property.baseName != null && !property.baseName.equals(property.name))
+                ? property.baseName
+                : property.name;
+            property.vendorExtensions.put("json-name", jsonName);
         }
         if(CodegenUtils.isPropertySchemaEnum(property)
             && !property.dataType.contains(ApplicationConstants.ENUM)
             && !property.dataType.contains("Instance.")) {
                 property.baseType = ApplicationConstants.ENUM + property.baseType;
                 property.dataType = ApplicationConstants.ENUM + property.dataType;
+                updateDataType(property.baseType, property.dataType, apiResourceBuilder, (dataTypeWithEnum, dataType) -> {
+                    property.datatypeWithEnum = dataTypeWithEnum;
+                    property.dataType = dataType;
+                });
+                property.baseType = property.dataType;
         }
-        updateDataType(property.baseType, property.dataType, apiResourceBuilder, (dataTypeWithEnum, dataType) -> {
-            property.datatypeWithEnum = dataTypeWithEnum;
-            property.dataType = dataType;
-        });
-        property.baseType = property.dataType;
     }
 
     /**

src/main/resources/twilio-python/modelClasses.handlebars

@@ -7,7 +7,7 @@
         def __init__(self, payload: Dict[str, Any]):
 
             {{#vars}}
-            self.{{name}}: Optional[{{{dataType}}}] = {{#if vendorExtensions.x-deserialize}}{{vendorExtensions.x-deserialize}}(payload.get("{{{name}}}")){{else}}payload.get("{{{name}}}"){{/if}}{{/vars}}
+            self.{{name}}: Optional[{{{dataType}}}] = {{#if vendorExtensions.x-deserialize}}{{vendorExtensions.x-deserialize}}(payload.get("{{{vendorExtensions.json-name}}}")){{else}}payload.get("{{{vendorExtensions.json-name}}}"){{/if}}{{/vars}}
 
         def to_dict(self):
             return {

src/main/resources/twilio-python/nestedResponseModel.handlebars

@@ -3,8 +3,8 @@
 Nested response model for {{name}}
 '''
 class {{name}}:
-  def __init__(self,{{#vars}}{{baseName}}: {{{dataType}}}{{#unless @last}}, {{/unless}}{{/vars}}):
-    {{#vars}}self.{{baseName}} = {{baseName}}
+  def __init__(self,{{#vars}}{{name}}: {{{dataType}}}{{#unless @last}}, {{/unless}}{{/vars}}):
+    {{#vars}}self.{{name}} = {{name}}
     {{/vars}}
 
 {{/models}}