lincc-frameworks / lincc-frameworks/nested-pandas

Can we convert dictionary-encoded parquet columns to Categorical Dtype?

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Dominant language
Python
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26
Forks
8
Avg merge
2d 2h
Merged PRs (30d)
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Description

For something like `band`, we know that there are only a few possible values, and parquet knows this too and does a dictionary-style encoding on those columns. Can we consider using this hint to convert those columns to Categorical Dtype and save space in-memory?

Is there an in-memory savings to be gained?

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First steps

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Research direction

No files or tests are identified. Start by finding the parquet-reading entry point and reproduce the `band` example with dictionary-encoded columns; compare memory use before and after conversion to Categorical Dtype, then document the conditions and expected behavior for a completed change.

Written by the indexing model from the issue text.

Assessment

Tech stack
pandas, python
Domain
data
Issue type
Feature
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Needs clarification
Newbie friendliness
35/100

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