Python implementation of SPL (Structured Process Language) - a grid-based data processing language with a spreadsheet-like Web IDE.

spl-python/
├── frontend/          # Vue + Univerjs spreadsheet UI (copied from spl-bun)
├── backend/           # Python FastAPI backend (multi-module)
│   ├── packages/
│   │   ├── spl_core/          # DataSet class and core operations
│   │   ├── spl_expression/    # Expression parser/evaluator
│   │   ├── spl_flow/          # Flow executor
│   │   ├── spl_web_server/    # FastAPI web server
│   │   └── spl_web_shared/    # Shared types and API routes
│   ├── pyproject.toml
│   └── README.md
└── doc/               # Project documentation (AI reference docs)

• Python >= 3.10
• uv (Python dependency manager)
• Bun (JS runtime + package manager)

Optional (for E2E):

• Playwright browser binaries

# Install Python dependencies (workspace)
cd backend
uv sync --all-packages --dev

# Run backend server (FastAPI/Uvicorn)
cd ..
bun run dev:backend

Backend defaults:

• URL: http://localhost:4176
• Health: GET /api/health
• Execute: POST /api/execute

Demo database initialization (on startup):

• data/demo-init.sql (base schema/data)
• data/demo-extension.sql (extension tables; idempotent)
• runtime DB: data/demo.db (usually ignored by .gitignore)

# Install JS dependencies
bun install

# Run frontend dev server
bun run dev:frontend

Frontend URL:

• http://localhost:4174

Playwright config (playwright.config.ts) will start both backend and frontend automatically.

# Install browsers (once)
bunx playwright install chromium

# Run e2e
bun run test:e2e

Backend server:

• PORT (default: 4176)
• SPL_WORKSPACE_ROOT (default: repo root)

Demo DB init:

• SPL_DEMO_DB_PATH (default: data/demo.db)
• SPL_DEMO_INIT_SQL_PATH (default: data/demo-init.sql)
• SPL_DEMO_EXTENSION_SQL_PATH (default: data/demo-extension.sql)
• SPL_DEMO_DB_RESET=1/true (force recreate db)

Optional server auto-shutdown:

• SPL_SERVER_SHUTDOWN_AFTER_SECONDS (if set, server exits after N seconds)

See doc/ for AI-generated reference documentation covering:

• Architecture overview
• Expression engine (60+ functions)
• Flow control statements
• Data sources
• DataSet API