fix(python): Fix regression in scan_parquet (#8071)

py-polars/polars/io/ipc/anonymous_scan.py

@@ -28,19 +28,23 @@ def _scan_ipc_fsspec(
 
 
 def _scan_ipc_impl(  # noqa: D417
-    source: str, columns: list[str] | None, **kwargs: Any
+    source: str,
+    columns: list[str] | None,
+    predicate: str | None,
+    n_rows: int | None,
+    **kwargs: Any,
 ) -> DataFrame:
     """
     Take the projected columns and materialize an arrow table.
 
     Parameters
     ----------
-    uri
+    source
         Source URI
     columns
         Columns that are projected
 
     """
     import polars as pl
 
-    return pl.read_ipc(source, columns=columns, **kwargs)
+    return pl.read_ipc(source, columns=columns, n_rows=n_rows, **kwargs)

py-polars/polars/io/parquet/anonymous_scan.py

@@ -28,19 +28,23 @@ def _scan_parquet_fsspec(
 
 
 def _scan_parquet_impl(  # noqa: D417
-    uri: str, columns: list[str] | None, **kwargs: Any
+    source: str,
+    columns: list[str] | None,
+    predicate: str | None,
+    n_rows: int | None,
+    **kwargs: Any,
 ) -> DataFrame:
     """
     Take the projected columns and materialize an arrow table.
 
     Parameters
     ----------
-    uri
+    source
         Source URI
     columns
         Columns that are projected
 
     """
     import polars as pl
 
-    return pl.read_parquet(uri, columns=columns, **kwargs)
+    return pl.read_parquet(source, columns=columns, n_rows=n_rows, **kwargs)

py-polars/polars/lazyframe/frame.py

@@ -502,7 +502,7 @@ def _scan_python_function(
         self = cls.__new__(cls)
         if isinstance(schema, dict):
             self._ldf = PyLazyFrame.scan_from_python_function_pl_schema(
-                [(name, dt) for name, dt in schema.items()], scan_fn, pyarrow
+                list(schema.items()), scan_fn, pyarrow
             )
         else:
             self._ldf = PyLazyFrame.scan_from_python_function_arrow_schema(