[BUG] Python Client allof get_discriminator_class() value Error=unhashable type: 'dict'

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
• Have you validated the input using an OpenAPI validator (example)?
• Have you tested with the latest master to confirm the issue still exists?
• Have you searched for related issues/PRs?
• What's the actual output vs expected output?
• [Optional] Sponsorship to speed up the bug fix or feature request (example)

Description

openapi-generator version

5.1/5.2

OpenAPI declaration file content or url

openapi: 3.0.1
info:
  title: Test
  version: 0.0.1
servers:
- url: http://localhost:8888/api/v1
tags:
- description: Authentication
  name: auth
paths:
  /authentication:
    post:
      operationId: login
      requestBody:
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/LoginPayload'
        description: Login information
        required: true
        x-body-name: body
      responses:
        "200":
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/UserResponse'
          description: successful operation
      summary: Login to the application
      tags:
      - auth
      x-codegen-request-body-name: body
      x-openapi-router-controller: openapi_server.controllers.auth_controller
    x-swagger-router-controller: auth
components:
  schemas:
    LoginPayload:
      example:
        payload:
          password: password
          login: login
      properties:
        payload:
          $ref: '#/components/schemas/Login'
      required:
      - payload
      type: object
    Login:
      example:
        password: password
        login: login
      properties:
        login:
          type: string
        password:
          type: string
      required:
      - login
      - password
      type: object
    Response:
      discriminator:
        propertyName: result
      example:
        result: result
        trace: trace
        statusText: statusText
        message: message
        errors:
        - errors
        statusCode: 0
      properties:
        statusText:
          type: string
        statusCode:
          type: integer
        result:
          type: string
        message:
          type: string
        errors:
          items:
            type: string
          type: array
        trace:
          type: string
      required:
      - message
      - result
      - statusCode
      - statusText
      type: object
    UserResponse:
      allOf:
      - $ref: '#/components/schemas/UserResponse_allOf'
      - $ref: '#/components/schemas/Response'
    User:
      properties:
        id:
          type: integer
        login:
          type: string
        firstName:
          type: string
        lastName:
          type: string
        email:
          type: string
      required:
      - email
      - firstName
      - id
      - lastName
      - login
      - roles
      type: object
    UserResponse_allOf:
      properties:
        result:
          $ref: '#/components/schemas/User'

Generation Details

java -jar ./openapi-generator-cl.jar generate -i ./testallof.yaml -g python \
--additional-properties=packageName=testallof \
-o ../testallof/

Steps to reproduce

1. Generate Python Client (v 5.2)

java -jar ./openapi-generator-cl.jar generate -i ./testallof.yaml -g python \
--additional-properties=packageName=testallof \
-o ../testallof/

2. Make Call to API using Python Client

with testallof.ApiClient(configuration) as api_client:
    # Create an instance of the API class
    api_instance = auth_api.AuthApi(api_client)
    try:
        login = Login('<username>', '<password>')
        lpl = LoginPayload(payload=login)
        # Returns necessary cookies to authenticate with embedded external services
        api_response = api_instance.login(body=lpl)
    except testallof.ApiException as e:
        print("Exception when calling AuthApi->authenticate_external_services: %s\n" % e)

3. The API Call fails when creating the Response instance at the code (model_utils.py)

def get_discriminator_class(model_class,
                            discr_name,
                            discr_value, cls_visited):
...
    if discr_name in model_class.discriminator:
        class_name_to_discr_class = model_class.discriminator[discr_name]
        used_model_class = class_name_to_discr_class.get(discr_value)

with the error

testallof.exceptions.ApiValueError: Invalid inputs given to generate an instance of 'Response'. The input data was invalid for the allOf schema 'Response' in the composed schema 'UserResponse'. Error=unhashable type: 'dict'

More Specifically the error is

get_discriminator_class
    used_model_class = class_name_to_discr_class.get(discr_value)
TypeError: unhashable type: 'dict'

4. the class_name_to_discr_class is a dictionary of values, even though in this example its a single allOf it returns it as a dictionary
   {'UserResponse': <class 'testallof.model.user_response.UserResponse'>}
5. discriminator value (discr_value) is a dictionary in this example:

{'id': 1, 'login': '<username>', 'firstName': '<firstname>', 'lastName': '<lastname>', 'email': 'email>', 'isActive': 1}

6. When doing the class_name_to_discr_class.get(discr_value) it is failing as it cannot lookup via another dictionary

Related issues/PRs

Suggest a fix

No Suggestion, still working out the further downstream logic and goal and becoming more familiar.. will update as i work through the issue

Start with the generated Python client and model_utils.py, especially get_discriminator_class(), using the supplied OpenAPI document and Java generation command. Reproduce the API call that constructs UserResponse and trace the discriminator and allOf values. Done means the generated client handles this response without the unhashable type: 'dict' error.