[Python] Some fixes for pydantic v1 templates for nested dicts

[ottmar-zittlau]

I fixed some issues with the pydantic v1 template concerning nested dicts (dicts of dicts and list of dicts).

The main issue is here here. Here, from_dict is called on the type hint [Dict[str, Tag]

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---

Summary by cubic

Fixes pydantic v1 templates to correctly (de)serialize nested dict/list containers and use valid Union[...] return types for discriminator models. Adds None-safe handling to prevent data loss and type errors for arrays of maps, maps of arrays, maps of maps, and lists of lists.

• Bug Fixes

  • Handle nested containers in to_dict/from_dict (list of maps, map of arrays, map of maps, lists of lists) with None checks, calling to_dict/from_dict on inner models.
  • Use correct typing: Union[...] in from_json/from_dict for discriminator returns.
  • Generate from_dict for arrays of dicts and to_dict for lists of maps.

• Refactors

  • Simplify generated code with dict/list comprehensions and literals; streamline enum/ref map handling.
  • Update samples to match the new template output.

^{Written for commit 63f7c80. Summary will update on new commits.}

[cubic-dev-ai]

2 issues found across 14 files

Prompt for AI agents (unresolved issues)

Check if these issues are valid — if so, understand the root cause of each and fix them. If appropriate, use sub-agents to investigate and fix each issue separately.


<file name="samples/openapi3/client/petstore/python-pydantic-v1/petstore_api/models/unnamed_dict_with_additional_model_list_properties.py">

<violation number="1" location="samples/openapi3/client/petstore/python-pydantic-v1/petstore_api/models/unnamed_dict_with_additional_model_list_properties.py:84">
P1: `from_dict` can crash on valid input because it unconditionally calls `.items()` on an optional `dictProperty` value.</violation>
</file>

<file name="samples/openapi3/client/petstore/python-pydantic-v1/petstore_api/models/array_of_map_model.py">

<violation number="1" location="samples/openapi3/client/petstore/python-pydantic-v1/petstore_api/models/array_of_map_model.py:64">
P1: `to_dict()` incorrectly iterates `_item.items` instead of `_item.items()`, causing a runtime TypeError during serialization.</violation>
</file>

_{Reply with feedback, questions, or to request a fix. Tag @cubic-dev-ai to re-run a review.}

[wing328]

thanks for the PR

can you please review the feedback from cubic-dev-ai when you've time?

[ottmar-zittlau]

thanks for the PR

can you please review the feedback from cubic-dev-ai when you've time?

@wing328 Yes, of course. I noticed that some java-related files have changed upon running the samples generation script. I didn't commit them, because I think these changes are unrelated to mine. But let me know if I should add them.