[PYTHON] Duplicate method definitions generated when requestBody has multiple content types (F811)

Description

When an OpenAPI 3.0 endpoint defines a requestBody with multiple content types (e.g., application/json and application/x-www-form-urlencoded), swagger-codegen generates duplicate Python methods with the same name but different signatures. This causes Python linting errors (F811: redefinition of unused name) and makes the first method unreachable since the second definition shadows it.

swagger-codegen version

swagger-codegen 3.0.75

OpenAPI declaration file content or url

/oauth2/token:
  post:
    operationId: exchangeOAuthCode
    requestBody:
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Oauth2TokenBody'
        application/x-www-form-urlencoded:
          schema:
            type: object
            properties:
              grant_type:
                type: string
              code:
                type: string
              client_id:
                type: string
              # ... additional form fields

Command line used for generation

swagger-codegen generate -i openapi.json -l python -o ./python-client

Steps to reproduce

1. Create an OpenAPI 3.0 spec with an endpoint that accepts both application/json and application/x-www-form-urlencoded content types
2. Generate a Python client using swagger-codegen
3. Run a Python linter (flake8, ruff, pylint) on the generated code

Related issues

This is the same root cause as:

• #11848 - [JAVA] requestBody's with multiple options for content generate duplicate methods
• #10331 - [SPRING] Multiple Content Types in APIs cause ambiguous mapping
• swagger-api/swagger-codegen-generators#441 - [Spring] Incorrect code generated for endpoints with multiple request types

Suggest a fix

Possible solutions:

1. Generate methods with unique names based on content type (e.g., exchange_o_auth_code_json, exchange_o_auth_code_form)
2. Generate a single method that can handle multiple content types via a parameter
3. Skip generating duplicate methods and only generate one (preferring JSON body)

Generated code example

The generator produces:

# First definition (JSON body) - lines 356-473
def exchange_o_auth_code(self, body, **kwargs):  # noqa: E501
    """Exchange OAuth credentials for JWT tokens"""
    ...

# Second definition (form params) - lines 475-634 - SHADOWS THE FIRST!
def exchange_o_auth_code(self, grant_type, code, client_id, client_secret, refresh_token, redirect_uri, code_verifier, state, **kwargs):  # noqa: E501
    """Exchange OAuth credentials for JWT tokens"""
    ...

Linter output:

F811 Redefinition of unused `exchange_o_auth_code` from line 356
   --> tmi_client/api/authentication_api.py:475:9

Reproduce the issue with the supplied OpenAPI declaration and swagger-codegen generate -i openapi.json -l python -o ./python-client, then inspect the generated authentication_api.py around lines 356-634. Determine how the Python generator handles multiple requestBody content types; done means the generated client has no duplicate method definition and passes a Python linter.