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?
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Description

PythonClientCodegen when run against openapi.yaml will produce the followin warning output.

[main] WARN  o.o.c.l.AbstractPythonCodegen - Type null not handled properly in toExampleValue

openapi-generator version

5.2.1

OpenAPI declaration file content or url

openapi: 3.0.0
info:
  title: API
  version: 1.0.0
paths:
  /pet:
    get:
      operationId: get_handler
      parameters:
      - in: query
        name: pet
        schema:
          $ref: '#/components/schemas/Dog'
      responses:
        '200':
          content:
            application/json:
              schema:
                type: object
          description: Success
components:
  schemas:
    Pet:
      type: object
      properties:
        pet_type:
          type: string
    Dog:
      allOf:
        - $ref: '#/components/schemas/Pet'
        - type: object
          properties:
            bark:
              type: boolean

Generation Details

openapi-generator generate -i openapi.yaml -g python-flask -t templates --package-name 

Steps to reproduce

Generate the client using the command above

Related issues/PRs

No similar PR

Suggest a fix

Handle the ComposedSchema example generation in AbstractPythonCodegen -> toExampleValueRecursive.