fix: eliminate variable shadowing in get_embedding and add list key support (Fixes #37)

[rtmalikian]

Fixes #37

Problem

get_embedding() has a variable shadowing bug: the loop for key in key_chain overwrites the function parameter key. While Python's loop semantics prevent a crash in most cases, this makes the code fragile and hard to maintain. Additionally, the key=None path was missing newline stripping that the key=str path had, causing inconsistent text cleaning.

Solution

Three changes to hyperdb/hyperdb.py:

1. Eliminate variable shadowing: Rename loop variable from key to k and use a value accumulator to traverse nested keys, keeping the original key parameter intact
2. Add list key support: When key is a list (e.g., key=["name", "city"]), extract those specific fields for concatenation — addresses the issue's concern about key type handling
3. Fix inconsistent newline stripping: Apply replace("\n", " ") in the key=None path, matching the behavior of the key=str path

Verification

PASS: nested key extraction
PASS: list key extraction
PASS: None key extraction
PASS: newline stripping in None-key path
PASS: deeply nested key
ALL TESTS PASSED

Contact

About the Author: Raphael Malikian — Clinical AI Solutions Architect. I specialise in building and fixing AI/ML systems for healthcare, including vector databases, RAG pipelines, and clinical NLP. If you need help with your project or think I can add value to your organisation, feel free to reach out — I'd love to connect.

📧 rtmalikian@gmail.com
🔗 GitHub: https://github.com/rtmalikian
🔗 LinkedIn: http://www.linkedin.com/in/raphael-t-malikian-mbbs-bsc-hons-71075436a

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Disclosure: This code was developed with assistance from mimo-v2.5-pro (Xiaomi) via Hermes Agent (Nous Research). All changes were reviewed, tested against the actual codebase, and verified for correctness.