Try lowering minimum pandas (#390)

.github/workflows/extremes.yml

@@ -26,10 +26,37 @@ jobs:
             $RUNNER_TOOL_CACHE/Python/*
             ~\AppData\Local\pip\Cache
           key: ${{ runner.os }}-build-${{ matrix.python-version }}
+      - name: install-minimu-versions
+        run: python -m pip install tox virtualenv setuptools pandas==0.25.3 polars==0.20.3 numpy==1.17.5 pyarrow==11.0.0 scipy==1.5.0 scikit-learn==1.1.0 tzdata
       - name: install-reqs
-        run: python -m pip install --upgrade tox virtualenv setuptools pip -r requirements-dev.txt
-      - name: install-modin
-        run: python -m pip install pandas==1.1.5 polars==0.20.3 numpy==1.17.5 pyarrow==11.0.0 scipy==1.5.0 scikit-learn==1.1.0 tzdata
+        run: python -m pip install -r requirements-dev.txt
+      - name: Run pytest
+        run: pytest tests --cov=narwhals --cov=tests --cov-fail-under=50 --runslow
+
+  pretty_old_versions:
+    strategy:
+      matrix:
+        python-version: ["3.8"]
+        os: [ubuntu-latest]
+
+    runs-on: ${{ matrix.os }}
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-python@v4
+        with:
+          python-version: ${{ matrix.python-version }}
+      - name: Cache multiple paths
+        uses: actions/cache@v4
+        with:
+          path: |
+            ~/.cache/pip
+            $RUNNER_TOOL_CACHE/Python/*
+            ~\AppData\Local\pip\Cache
+          key: ${{ runner.os }}-build-${{ matrix.python-version }}
+      - name: install-minimu-versions
+        run: python -m pip install tox virtualenv setuptools pandas==1.1.5 polars==0.20.3 numpy==1.17.5 pyarrow==11.0.0 scipy==1.5.0 scikit-learn==1.1.0 tzdata
+      - name: install-reqs
+        run: python -m pip install -r requirements-dev.txt
       - name: Run pytest
         run: pytest tests --cov=narwhals --cov=tests --cov-fail-under=50 --runslow
       - name: Run doctests

narwhals/_pandas_like/dataframe.py

@@ -334,7 +334,7 @@ def join(
                 .rename(  # rename to avoid creating extra columns in join
                     columns=dict(zip(right_on, left_on))  # type: ignore[arg-type]
                 )
-                .drop_duplicates(ignore_index=True)
+                .drop_duplicates()
             )
             return self._from_dataframe(
                 self._dataframe.merge(

narwhals/_pandas_like/group_by.py

@@ -154,7 +154,7 @@ def func(df: Any) -> Any:
         for expr in exprs:
             results_keys = expr._call(from_dataframe(df))
             for result_keys in results_keys:
-                out_group.append(result_keys._series.item())
+                out_group.append(result_keys._series.iloc[0])
                 out_names.append(result_keys.name)
         return native_series_from_iterable(
             out_group, index=out_names, name="", implementation=implementation

narwhals/_pandas_like/series.py

@@ -434,9 +434,14 @@ def alias(self, name: str) -> Self:
     def to_numpy(self) -> Any:
         has_missing = self._series.isna().any()
         if has_missing and str(self._series.dtype) in PANDAS_TO_NUMPY_DTYPE_MISSING:
+            if self._implementation == "pandas" and parse_version(
+                get_pandas().__version__
+            ) < parse_version("1.0.0"):  # pragma: no cover
+                kwargs = {}
+            else:
+                kwargs = {"na_value": float("nan")}
             return self._series.to_numpy(
-                dtype=PANDAS_TO_NUMPY_DTYPE_MISSING[str(self._series.dtype)],
-                na_value=float("nan"),
+                dtype=PANDAS_TO_NUMPY_DTYPE_MISSING[str(self._series.dtype)], **kwargs
             )
         if (
             not has_missing

narwhals/_pandas_like/utils.py

@@ -74,9 +74,9 @@ def validate_dataframe_comparand(index: Any, other: Any) -> Any:
     if isinstance(other, PandasSeries):
         if other.len() == 1:
             # broadcast
-            return other._series.item()
-        if other._series.index is not index and not (other._series.index == index).all():
-            return other._series.set_axis(index, axis=0)
+            return other._series.iloc[0]
+        if other._series.index is not index:
+            return set_axis(other._series, index, implementation=other._implementation)
         return other._series
     raise AssertionError("Please report a bug")
 
@@ -375,12 +375,19 @@ def native_series_from_iterable(
 
 
 def set_axis(obj: T, index: Any, implementation: str) -> T:
+    if implementation == "pandas" and parse_version(
+        get_pandas().__version__
+    ) < parse_version("1.0.0"):  # pragma: no cover
+        kwargs = {"inplace": False}
+    else:
+        kwargs = {}
     if implementation == "pandas" and parse_version(
         get_pandas().__version__
     ) >= parse_version("1.5.0"):
-        return obj.set_axis(index, axis=0, copy=False)  # type: ignore[no-any-return, attr-defined]
+        kwargs["copy"] = False
     else:  # pragma: no cover
-        return obj.set_axis(index, axis=0)  # type: ignore[no-any-return, attr-defined]
+        pass
+    return obj.set_axis(index, axis=0, **kwargs)  # type: ignore[no-any-return, attr-defined]
 
 
 def translate_dtype(column: Any) -> DType:
@@ -591,7 +598,7 @@ def validate_indices(series: list[PandasSeries]) -> list[Any]:
     reindexed = [series[0]._series]
     for s in series[1:]:
         if s._series.index is not idx:
-            reindexed.append(s._series.set_axis(idx.rename(s._series.index.name), axis=0))
+            reindexed.append(set_axis(s._series, idx, s._implementation))
         else:
             reindexed.append(s._series)
     return reindexed

pyproject.toml

@@ -18,7 +18,7 @@ classifiers = [
 ]
 
 [project.optional-dependencies]
-pandas = ["pandas>=1.1.5"]
+pandas = ["pandas>=0.25.3"]
 polars = ["polars>=0.20.3"]
 pyarrow = ['pyarrow>=11.0.0']
 
@@ -77,6 +77,7 @@ docstring-code-format = true
 filterwarnings = [
   "error",
   'ignore:distutils Version classes are deprecated:DeprecationWarning',
+  'ignore:In the future `np.bool`',
 ]
 xfail_strict = true
 markers = ["slow: marks tests as slow (deselect with '-m \"not slow\"')"]

tests/frame/test_common.py

@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 import re
+import warnings
 from typing import TYPE_CHECKING
 from typing import Any
 from typing import Literal
@@ -12,7 +13,6 @@
 import pytest
 from pandas.testing import assert_series_equal as pd_assert_series_equal
 from polars.testing import assert_series_equal as pl_assert_series_equal
-from sklearn.utils._testing import ignore_warnings
 
 import narwhals as nw
 from narwhals.functions import _get_deps_info
@@ -444,6 +444,10 @@ def test_accepted_dataframes() -> None:
 
 @pytest.mark.parametrize("df_raw", [df_polars, df_pandas, df_mpd])
 @pytest.mark.filterwarnings("ignore:.*Passing a BlockManager.*:DeprecationWarning")
+@pytest.mark.skipif(
+    parse_version(pd.__version__) < parse_version("2.0.0"),
+    reason="too old for pandas-pyarrow",
+)
 def test_convert_pandas(df_raw: Any) -> None:
     result = nw.from_native(df_raw).to_pandas()  # type: ignore[union-attr]
     expected = pd.DataFrame({"a": [1, 3, 2], "b": [4, 4, 6], "z": [7.0, 8, 9]})
@@ -851,7 +855,9 @@ def test_with_columns_order_single_row(df_raw: Any) -> None:
 
 
 def test_get_sys_info() -> None:
-    with ignore_warnings():
+    with warnings.catch_warnings():
+        warnings.filterwarnings("ignore")
+        show_versions()
         sys_info = _get_sys_info()
 
     assert "python" in sys_info
@@ -860,7 +866,9 @@ def test_get_sys_info() -> None:
 
 
 def test_get_deps_info() -> None:
-    with ignore_warnings():
+    with warnings.catch_warnings():
+        warnings.filterwarnings("ignore")
+        show_versions()
         deps_info = _get_deps_info()
 
     assert "narwhals" in deps_info
@@ -873,7 +881,8 @@ def test_get_deps_info() -> None:
 
 
 def test_show_versions(capsys: Any) -> None:
-    with ignore_warnings():
+    with warnings.catch_warnings():
+        warnings.filterwarnings("ignore")
         show_versions()
         out, err = capsys.readouterr()
 

tests/frame/test_invalid.py

@@ -1,8 +1,6 @@
 import pandas as pd
 import polars as pl
 import pytest
-from sklearn.utils import check_X_y
-from sklearn.utils._testing import create_memmap_backed_data
 
 import narwhals as nw
 from narwhals.utils import parse_version
@@ -33,6 +31,9 @@ def test_validate_laziness() -> None:
 )
 def test_memmap() -> None:
     # the headache this caused me...
+    from sklearn.utils import check_X_y
+    from sklearn.utils._testing import create_memmap_backed_data
+
     x_any = pd.DataFrame({"a": [1, 2, 3], "b": [4, 5, 6]})
     y_any = create_memmap_backed_data(x_any["b"])
 

tests/frame/write_parquet_test.py

@@ -1,17 +1,20 @@
 from __future__ import annotations
 
 import os
-from typing import TYPE_CHECKING
 from typing import Any
 
+import pandas as pd
+import pytest
+
 import narwhals as nw
+from narwhals.utils import parse_version
 
 data = {"a": [1, 2, 3]}
 
-if TYPE_CHECKING:
-    import pytest
-
 
+@pytest.mark.skipif(
+    parse_version(pd.__version__) < parse_version("2.0.0"), reason="too old for pyarrow"
+)
 def test_write_parquet(constructor: Any, tmpdir: pytest.TempdirFactory) -> None:
     path = str(tmpdir / "foo.parquet")  # type: ignore[operator]
     nw.from_native(constructor(data), eager_only=True).write_parquet(path)

tests/hypothesis/test_join.py

@@ -11,6 +11,7 @@
 from narwhals.utils import parse_version
 
 pl_version = parse_version(pl.__version__)
+pd_version = parse_version(pd.__version__)
 
 
 @given(
@@ -37,6 +38,7 @@
     ),
 )  # type: ignore[misc]
 @pytest.mark.skipif(pl_version < parse_version("0.20.13"), reason="0.0 == -0.0")
+@pytest.mark.skipif(pd_version < parse_version("2.0.0"), reason="requires pyarrow")
 @pytest.mark.slow()
 def test_join(  # pragma: no cover
     integers: st.SearchStrategy[list[int]],
@@ -84,6 +86,7 @@ def test_join(  # pragma: no cover
     ),
 )  # type: ignore[misc]
 @pytest.mark.slow()
+@pytest.mark.skipif(pd_version < parse_version("2.0.0"), reason="requires pyarrow")
 def test_cross_join(  # pragma: no cover
     integers: st.SearchStrategy[list[int]],
     other_integers: st.SearchStrategy[list[int]],

tests/series/test_common.py

@@ -141,6 +141,9 @@ def test_boolean_reductions(df_raw: Any) -> None:
 
 
 @pytest.mark.parametrize("df_raw", [df_pandas, df_lazy])
+@pytest.mark.skipif(
+    parse_version(pd.__version__) < parse_version("2.0.0"), reason="too old for pyarrow"
+)
 def test_convert(df_raw: Any) -> None:
     result = nw.from_native(df_raw).lazy().collect()["a"].to_numpy()
     assert_array_equal(result, np.array([1, 3, 2]))
@@ -271,6 +274,10 @@ def test_zip_with(df_raw: Any, mask: Any, expected: Any) -> None:
     assert result == expected
 
 
+@pytest.mark.skipif(
+    parse_version(pd.__version__) < parse_version("1.0.0"),
+    reason="too old for convert_dtypes",
+)
 def test_cast_string() -> None:
     s_pd = pd.Series([1, 2]).convert_dtypes()
     s = nw.from_native(s_pd, series_only=True)

tests/test_utils.py

@@ -5,6 +5,7 @@
 from pandas.testing import assert_series_equal
 
 import narwhals as nw
+from narwhals.utils import parse_version
 
 
 def test_maybe_align_index_pandas() -> None:
@@ -64,6 +65,10 @@ def test_maybe_set_index_polars() -> None:
     assert result is df
 
 
+@pytest.mark.skipif(
+    parse_version(pd.__version__) < parse_version("1.0.0"),
+    reason="too old for convert_dtypes",
+)
 def test_maybe_convert_dtypes_pandas() -> None:
     import numpy as np
 

tests/tpch_q1_test.py

@@ -9,6 +9,7 @@
 import pytest
 
 import narwhals as nw
+from narwhals.utils import parse_version
 from tests.utils import compare_dicts
 
 
@@ -17,6 +18,9 @@
     ["pandas", "polars"],
 )
 @pytest.mark.filterwarnings("ignore:.*Passing a BlockManager.*:DeprecationWarning")
+@pytest.mark.skipif(
+    parse_version(pd.__version__) < parse_version("1.0.0"), reason="too old for pyarrow"
+)
 def test_q1(library: str) -> None:
     if library == "pandas":
         df_raw = pd.read_parquet("tests/data/lineitem.parquet")
@@ -84,6 +88,9 @@ def test_q1(library: str) -> None:
     "ignore:.*Passing a BlockManager.*:DeprecationWarning",
     "ignore:.*Complex.*:UserWarning",
 )
+@pytest.mark.skipif(
+    parse_version(pd.__version__) < parse_version("1.0.0"), reason="too old for pyarrow"
+)
 def test_q1_w_generic_funcs(library: str) -> None:
     if library == "pandas":
         df_raw = pd.read_parquet("tests/data/lineitem.parquet")
@@ -144,6 +151,9 @@ def test_q1_w_generic_funcs(library: str) -> None:
 
 @mock.patch.dict(os.environ, {"NARWHALS_FORCE_GENERIC": "1"})
 @pytest.mark.filterwarnings("ignore:.*Passing a BlockManager.*:DeprecationWarning")
+@pytest.mark.skipif(
+    parse_version(pd.__version__) < parse_version("1.0.0"), reason="too old for pyarrow"
+)
 def test_q1_w_pandas_agg_generic_path() -> None:
     df_raw = pd.read_parquet("tests/data/lineitem.parquet")
     df_raw["l_shipdate"] = pd.to_datetime(df_raw["l_shipdate"])