Revert "fix: Use importlib for polars version (#2952)", xfail map_batches test for now (#2996)

* Revert "fix: Use `importlib` for `polars` version (#2952)"

This reverts commit bb740d2.

* xfail test

* comment out pyarrow nightly

* nightly

Author: MarcoGorelli

.github/workflows/extremes.yml

@@ -152,8 +152,10 @@ jobs:
           uv pip install pandas --pre --index https://pypi.anaconda.org/scientific-python-nightly-wheels/simple --system -U
       - name: install pyarrow nightly
         run: |
-          uv pip uninstall pyarrow --system
-          uv pip install pyarrow --pre --index https://pypi.fury.io/arrow-nightlies/ --system -U
+          # commented out nightly whilst it fails to install
+          uv pip install -U pyarrow --system
+          # uv pip uninstall pyarrow --system
+          # uv pip install pyarrow --pre --index https://pypi.fury.io/arrow-nightlies/ --system -U
       - name: install numpy nightly
         run: |
           uv pip uninstall numpy --system
@@ -172,7 +174,7 @@ jobs:
         run: |
           DEPS=$(uv pip freeze)
           echo "$DEPS" | grep 'pandas.*dev'
-          echo "$DEPS" | grep 'pyarrow.*dev'
+          # echo "$DEPS" | grep 'pyarrow.*dev'
           echo "$DEPS" | grep 'numpy.*dev'
           echo "$DEPS" | grep 'dask.*@'
       - name: Run pytest

narwhals/_utils.py

@@ -603,11 +603,7 @@ def backend_version(implementation: Implementation, /) -> tuple[int, ...]:
     impl = implementation
     module_name = _IMPLEMENTATION_TO_MODULE_NAME.get(impl, impl.value)
     native_namespace = _import_native_namespace(module_name)
-    if impl.is_polars():
-        from importlib import metadata
-
-        into_version = metadata.version("polars")
-    elif impl.is_sqlframe():
+    if impl.is_sqlframe():
         import sqlframe._version
 
         into_version = sqlframe._version

tests/expr_and_series/map_batches_test.py

@@ -1,5 +1,7 @@
 from __future__ import annotations
 
+import pytest
+
 import narwhals as nw
 from tests.utils import ConstructorEager, assert_equal_data
 
@@ -12,7 +14,12 @@ def test_map_batches_expr(constructor_eager: ConstructorEager) -> None:
     assert_equal_data(expected, {"a": [2, 3, 4], "b": [5, 6, 7]})
 
 
-def test_map_batches_expr_numpy(constructor_eager: ConstructorEager) -> None:
+def test_map_batches_expr_numpy(
+    constructor_eager: ConstructorEager, request: pytest.FixtureRequest
+) -> None:
+    if "polars" in str(constructor_eager):
+        # https://github.com/narwhals-dev/narwhals/issues/2995
+        request.applymarker(pytest.mark.xfail(strict=False))
     df = nw.from_native(constructor_eager(data))
     expected = df.select(
         nw.col("a")

tests/utils.py

@@ -25,8 +25,6 @@
 
 def get_module_version_as_tuple(module_name: str) -> tuple[int, ...]:
     try:
-        if module_name == "polars":
-            return Implementation.POLARS._backend_version()
         return parse_version(__import__(module_name).__version__)
     except ImportError:
         return (0, 0, 0)