[PR] feat(python/sedonadb): add aggregate expression methods on Expr [sedona-db]

["jiayuasu (via GitHub)" <gi...@apache.org>]

jiayuasu opened a new pull request, #882:
URL: https://github.com/apache/sedona-db/pull/882

   First step toward grouping/aggregation, per the reprioritization recorded on #791 (aggregation/join/UDFs ahead of the remaining small schema ops).
   
   ## What's new
   
   Aggregate builder methods on `Expr`:
   
   ```python
   col("x").sum()      # Expr(sum(x))
   col("x").count()    # Expr(count(x))
   col("x").mean()     # Expr(avg(x))
   col("x").min()      # Expr(min(x))
   col("x").max()      # Expr(max(x))
   ```
   
   - **Methods on `Expr`** (matching Polars / PySpark) rather than free functions — consistent with the operator-method pattern already on `Expr`.
   - **`mean`** maps to DataFusion's `avg` aggregate but is named for the pandas/Polars vocabulary.
   - Each wraps the corresponding helper from `datafusion::functions_aggregate::expr_fn`.
   
   ## Scope
   
   This PR ships **only the expression builders**. The resulting `Expr` is an aggregate AST node — valid only inside an aggregation context (`DataFrame.agg(...)` / `group_by().agg()`), which come in follow-up PRs. Shipping the builders in isolation mirrors how the original `Expr` foundation (#807) landed before any DataFrame integration existed; tests are repr-level.
   
   Planned follow-ups:
   1. `df.agg(*exprs)` — global (ungrouped) aggregation.
   2. `df.group_by(*keys).agg(*exprs)` — the `GroupedDataFrame` layer.
   
   ## Test plan
   
   6 tests in `tests/expr/test_expression.py`:
   - Parametrized exact-`repr()` check for all five aggregates.
   - Aggregate over a compound expression (`(col("x") + col("y")).sum()` → `Expr(sum(x + y))`).
   
   Local: 54 expression tests + 15 doctests + `ruff format` + `ruff check` all clean.
   


-- 
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.

To unsubscribe, e-mail: issues-unsubscribe@sedona.apache.org

For queries about this service, please contact Infrastructure at:
users@infra.apache.org

Re: [PR] feat(python/sedonadb): add aggregate expression methods on Expr [sedona-db]

["jiayuasu (via GitHub)" <gi...@apache.org>]

jiayuasu closed pull request #882: feat(python/sedonadb): add aggregate expression methods on Expr
URL: https://github.com/apache/sedona-db/pull/882


-- 
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.

To unsubscribe, e-mail: issues-unsubscribe@sedona.apache.org

For queries about this service, please contact Infrastructure at:
users@infra.apache.org

Re: [PR] feat(python/sedonadb): add aggregate expression methods on Expr [sedona-db]

["jiayuasu (via GitHub)" <gi...@apache.org>]

jiayuasu commented on PR #882:
URL: https://github.com/apache/sedona-db/pull/882#issuecomment-4560984634

   Closing in favor of the approach in #885 — exposing scalar and aggregate UDFs through a registry-walking `sd.funcs.<name>(args)` dispatch rather than hand-rolling per-function methods on `Expr`. That mechanism:
   
   - avoids growing the Rust bindings by one method per aggregate,
   - automatically surfaces plugin and Python-registered UDFs that a hard-coded list would miss,
   - uses one path for scalar (spatial `st_*`) and aggregate functions instead of two parallel mechanisms.
   
   Once #885 lands I'll build `DataFrame.agg(...)` and `DataFrame.group_by(...).agg(...)` on top, with call sites like `sd.funcs.sum(col("x"))`. The repr-level tests from this PR will move to that follow-up.


-- 
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.

To unsubscribe, e-mail: issues-unsubscribe@sedona.apache.org

For queries about this service, please contact Infrastructure at:
users@infra.apache.org