chore: use constructors (#1210)

Author: FBruzzesi

tests/expr_and_series/str/contains_test.py

@@ -1,7 +1,5 @@
 from __future__ import annotations
 
-import pandas as pd
-import polars as pl
 import pytest
 
 import narwhals.stable.v1 as nw
@@ -11,9 +9,6 @@
 
 data = {"pets": ["cat", "dog", "rabbit and parrot", "dove"]}
 
-df_pandas = pd.DataFrame(data)
-df_polars = pl.DataFrame(data)
-
 
 def test_contains_case_insensitive(
     constructor: Constructor, request: pytest.FixtureRequest

tests/series_only/cast_test.py

@@ -2,6 +2,7 @@
 
 from datetime import date
 from datetime import datetime
+from typing import TYPE_CHECKING
 
 import pandas as pd
 import polars as pl
@@ -12,16 +13,18 @@
 import narwhals.stable.v1 as nw
 from narwhals.utils import parse_version
 
+if TYPE_CHECKING:
+    from tests.utils import ConstructorEager
 
-def test_cast_253() -> None:
-    df_polars = pl.DataFrame({"a": [1]})
-    result = nw.from_native(df_polars, eager_only=True).select(
-        nw.col("a").cast(nw.String) + "hi"
-    )["a"][0]
-    assert result == "1hi"
 
-    df_pandas = pd.DataFrame({"a": [1]})
-    result = nw.from_native(df_pandas, eager_only=True).select(
+def test_cast_253(
+    request: pytest.FixtureRequest, constructor_eager: ConstructorEager
+) -> None:
+    if "pyarrow_table" in str(constructor_eager):
+        request.applymarker(pytest.mark.xfail)
+
+    df_raw = constructor_eager({"a": [1]})
+    result = nw.from_native(df_raw, eager_only=True).select(
         nw.col("a").cast(nw.String) + "hi"
     )["a"][0]
     assert result == "1hi"