fill documentation with life and style

[maxnutz]

fill documentation with life and style

Implementation plan. Split into 3 independent, incremental PRs.

1. Clean up API reference — hide non-function members from utils.py docs

Problem: docs/api/utils.md renders ::: pypsa_validation_processing.utils with members: true, which dumps the module's 3 helper functions and its 5 module-level dicts (REGION_MAPPING, UNITS_MAPPING, statistics_kwargs, statistics_kwargs_for_filtering, statistics_kwargs_for_imports) into the API page. Only the functions should show.

Approach: explicit members: allowlist, scoped to docs/api/utils.md only (no code changes in utils.py).

Files:

• docs/api/utils.md — add local mkdocstrings options block:

  # Utilities API
  
  ::: pypsa_validation_processing.utils
      options:
        members:
          - remap_unit_index
          - get_energy_totals_domestic_share
          - create_location_index_from_copperplate

• No changes needed to docs/api/class_definitions.md, statistics_functions.md, workflow.md, package.md — verify each of those doesn't have the same dict-leak problem (spot-check class_definitions.py / statistics_functions.py for stray module-level constants) and apply the same allowlist pattern if needed.

Trade-off accepted: the allowlist must be updated by hand whenever a new public helper is added to utils.py. This is intentional (per decision) — flag it in the PR description so reviewers know to update docs/api/utils.md alongside new helpers. Add a short note to the README stating, for documentation of new files in utils, this list has to be manually updated.

Branch: 82-fix-api-docs-helper-functions

Verification: pixi run mkdocs build (or equivalent doc build command) and visually confirm utils.md page shows exactly 3 functions, no dicts.

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2. Add a contributing / coding-style docs page

Problem: issue asks for "general information and participation coding styles" — currently this lives only in CLAUDE.md (agent-facing) and partially in README's "Variable's Statistics - Functions" section. There's no human-facing contributor doc on the site.

Approach: new docs/contributing.md, added to mkdocs.yml nav. README stays as-is (no trimming) — the docs page is additive, not a replacement, so existing README readers aren't affected.

Content to consolidate into docs/contributing.md:

• Project context (short): PyPSA-AT, IAMC variables, links to energy-scenarios-at-workflow.
• Code style: Python ≥ 3.12, type hints required, NumPy-style docstrings, pixi run black ..
• Function architecture rules: statistics functions in statistics_functions.py are independent and may only call utils.py helpers; utils.py helpers may call each other but never statistics functions.
• Statistics-function conventions (mirrors/expands README section): naming convention (| → __, spaces → _), fixed signature (n: pypsa.Network, aggregate_per_year: bool), return format rules (Series vs DataFrame, required location/unit index levels), the configs/mapping.default.yaml lookup mechanism.
• Testing rules: unit tests only in tests/, output-format assertions (pandas.Series with MultiIndex containing at least country/unit), add/update tests only when behavior changes.
• Contribution workflow: open an issue first (link "New Variable Statistics" issue template), branch-per-issue, PR checklist (pixi run test, pixi run workflow_test, no debug/TODO leftovers), assign @maxnutz as reviewer.

Files:

• docs/contributing.md (new)
• mkdocs.yml — add Contributing: contributing.md to nav:

Branch: 82-add-contributing-docs

Verification: pixi run mkdocs build, check nav renders, links resolve (no dead internal links).

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3. Document the Scenario Explorer on the docs landing page

Problem: no documentation exists yet on what the Scenario Explorer is or how to use it with this package's output.

Approach: rewrite docs/index.md entirely (not just append) to lead with this information, since it's flagged as important for PyPSA-AT users and should not be buried below the API-reference pointer.

Content (from issue body):

• Explorer URL: https://pypsa-at-dev.apps.ece.iiasa.ac.at/
• Requires user registration on the site.
• Explorer accepts all model names starting with "Pypsa-AT v1.0".
• The model name must be exactly one of the models set in the mappings file — cross-check against this package's model_name config value and the Network_Processor default (e4c6652 recently set a default model_name matching this mapping — confirm consistency).
• Large-file submissions can take a while; user is notified by e-mail on success.
• This package's output is already formatted to fit Scenario Explorer submission requirements — call out relevant config flags (map_country_codes_to_names, convert_units, aggregation_level) that affect submission validity.

Proposed new structure for docs/index.md:

# PyPSA Validation Processing

<short project intro — 1-2 sentences>

## Scenario Explorer

<explorer info as above>

## API Reference

Use the API Reference section (nav) for the automatically rendered module documentation.

## Contributing

See [Contributing](contributing.md) for coding-style and participation guidelines.

Files:

• docs/index.md (full rewrite)

Branch: 82-add-scenario-explorer-info

Verification: pixi run mkdocs build, manually review rendered landing page.

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Suggested execution order

1. PR 1 (API doc filter) — smallest, no content-writing, quick win.
2. PR 3 (Scenario Explorer info) — self-contained, high user value, content already given in the issue.
3. PR 2 (Contributing page) — largest, benefits from PR 1 being merged first (can link to the now-clean API reference).

Each PR closes out one checkbox of this issue; issue #82 stays open until all three are merged, then close manually (the CSS checkbox is already done).