Ensure DAG pipeline isolates node inputs

[robitec97]

Hello,
I've tried to fix a few things mentioned in your issue: #2

• Ensured _get_args_for_node deep copies dependency values so DAG pipeline nodes receive isolated inputs rather than shared references.

• Added a regression test confirming branches that share a source node get independent copies even when one consumer mutates its input.

Testing

• pytest datapizza-ai-core/datapizza/pipeline/tests/test_graph_pipeline.py

[AndreaBozzo]

Hi Roby, i noticed you referenced the Issue #2.

I avoided submitting a PR on this as i have no real Infos of the future intents about deepcopy usage, as Is pretty damn expensive on performances.

Still waiting on a clarification from dp Dev team on It.

[robitec97]

Hello Andrea, you’re absolutely right. I’m so sorry! :) I’ll remove my PR, I really didn’t mean to take any credit.

[AndreaBozzo]

@robitec97 Sorry Bro i didn't mean to remove the PR, i Just meant that i needed more Infos about that from the Dev team, i have absolutely no problems with you submitting a PR for Issue #2, i Just wanted to add more context.

Your PR is legit, keep It open imo

[Federaffo]

We haven't added deepcopy yet because we get an error while deepcopying the memory returned by ChatPromptTemplate
You can reproduce the error running a DagPipeline

"TypeError: Template.new() missing 1 required positional argument: 'source'"

[AndreaBozzo]

Grazie @Federaffo for the hint, i'll be looking on this.

Constructors apparently do not accept the empty invocation, could possibly use a more complex template to handle/avoid deepcopying the Jinja templates.