chore: use is_scalar_like in apply_n_ary_operation (#2242)

* chore: use is_scalar_like in apply_n_ary_operation

* updadte readme

Author: MarcoGorelli

README.md

@@ -14,8 +14,8 @@
 
 Extremely lightweight and extensible compatibility layer between dataframe libraries!
 
-- **Full API support**: cuDF, Modin, pandas, Polars, PyArrow
-- **Lazy-only support**: Dask. Work in progress: DuckDB, Ibis, PySpark.
+- **Full API support**: cuDF, Modin, pandas, Polars, PyArrow.
+- **Lazy-only support**: Dask, SQLFrame, PySpark. Work in progress: DuckDB, Ibis.
 
 Seamlessly support all, without depending on any!
 

docs/index.md

@@ -5,12 +5,12 @@
 [![PyPI version](https://badge.fury.io/py/narwhals.svg)](https://badge.fury.io/py/narwhals)
 [![Downloads](https://static.pepy.tech/badge/narwhals/month)](https://pepy.tech/project/narwhals)
 [![Trusted publishing](https://img.shields.io/badge/Trusted_publishing-Provides_attestations-bright_green)](https://peps.python.org/pep-0740/)
+[![PYPI - Types](https://img.shields.io/pypi/types/narwhals)](https://pypi.org/project/narwhals)
 
 Extremely lightweight and extensible compatibility layer between dataframe libraries!
 
-- **Full API support**: cuDF, Modin, pandas, Polars, PyArrow
-- **Lazy-only support**: Dask
-- **Interchange-level support**: DuckDB, Ibis, Vaex, anything which implements the DataFrame Interchange Protocol
+- **Full API support**: cuDF, Modin, pandas, Polars, PyArrow.
+- **Lazy-only support**: Dask, SQLFrame, PySpark. Work in progress: DuckDB, Ibis.
 
 Seamlessly support all, without depending on any!
 

narwhals/_expression_parsing.py

@@ -195,6 +195,9 @@ def __init_subclass__(cls, /, *args: Any, **kwds: Any) -> Never:  # pragma: no c
         msg = f"Cannot subclass {cls.__name__!r}"
         raise TypeError(msg)
 
+    def __repr__(self) -> str:
+        return f"ExprMetadata(kind: {self._kind}, n_open_windows: {self._n_open_windows})"
+
     @property
     def kind(self) -> ExprKind:
         return self._kind
@@ -320,9 +323,7 @@ def apply_n_ary_operation(
     broadcast = any(kind.preserves_length() for kind in kinds)
     compliant_exprs = (
         compliant_expr.broadcast(kind)
-        if broadcast
-        and (kind is ExprKind.LITERAL or kind is ExprKind.AGGREGATION)
-        and is_compliant_expr(compliant_expr)
+        if broadcast and is_compliant_expr(compliant_expr) and is_scalar_like(kind)
         else compliant_expr
         for compliant_expr, kind in zip(compliant_exprs, kinds)
     )