Implement a sieve that drops Pandas>=1.2 on Python 3.6

setup.py

@@ -89,6 +89,7 @@ def run_tests(self):
         "thoth.adviser.sieves",
         "thoth.adviser.sieves.backports",
         "thoth.adviser.sieves.tensorflow",
+        "thoth.adviser.sieves.pandas",
         "thoth.adviser.sieves.setuptools",
         "thoth.adviser.steps",
         "thoth.adviser.steps",

tests/sieves/pandas/__init__.py

@@ -0,0 +1,18 @@
+#!/usr/bin/env python3
+# thoth-adviser
+# Copyright(C) 2020 Fridolin Pokorny
+#
+# This program is free software: you can redistribute it and / or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+"""Tests for sieve units for Pandas."""

tests/sieves/pandas/test_py36_drop.py

@@ -0,0 +1,102 @@
+#!/usr/bin/env python3
+# thoth-adviser
+# Copyright(C) 2020 Fridolin Pokorny
+#
+# This program is free software: you can redistribute it and / or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+"""Test sieve to filter out Pandas>=1.2 on Python 3.6."""
+
+import flexmock
+import pytest
+
+from thoth.adviser.enums import DecisionType
+from thoth.adviser.enums import RecommendationType
+from thoth.adviser.pipeline_builder import PipelineBuilderContext
+from thoth.adviser.sieves import PandasPy36Drop
+from thoth.python import PackageVersion
+from thoth.python import Source
+
+from ...base import AdviserTestCase
+
+
+class TestPandasPy36DropSieve(AdviserTestCase):
+    """Test sieve to filter out Pandas>=1.2 on Python 3.6."""
+
+    @pytest.mark.parametrize(
+        "recommendation_type",
+        [RecommendationType.STABLE, RecommendationType.PERFORMANCE, RecommendationType.SECURITY,],
+    )
+    def test_include(self, builder_context: PipelineBuilderContext, recommendation_type: RecommendationType,) -> None:
+        """Test including this pipeline unit."""
+        builder_context.recommendation_type = recommendation_type
+        builder_context.project.runtime_environment.python_version = "3.6"
+
+        assert builder_context.is_adviser_pipeline()
+        assert PandasPy36Drop.should_include(builder_context) == {}
+
+    @pytest.mark.parametrize(
+        "recommendation_type,decision_type,python_version",
+        [
+            (RecommendationType.TESTING, None, "3.6"),
+            (RecommendationType.LATEST, None, "3.6"),
+            (None, DecisionType.RANDOM, "3.6"),
+            (RecommendationType.STABLE, None, "3.9"),
+            (RecommendationType.PERFORMANCE, None, "3.8"),
+        ],
+    )
+    def test_no_include(
+        self,
+        builder_context: PipelineBuilderContext,
+        recommendation_type: RecommendationType,
+        decision_type: DecisionType,
+        python_version: str,
+    ) -> None:
+        """Test not including this pipeline unit step."""
+        builder_context.decision_type = decision_type
+        builder_context.recommendation_type = recommendation_type
+        builder_context.project.runtime_environment.python_version = python_version
+        assert PandasPy36Drop.should_include(builder_context) is None
+
+    @pytest.mark.parametrize("pandas_version", ["1.2.0", "2.0.0"])
+    def test_run(self, pandas_version: str) -> None:
+        """Test filtering out Pandas that dropped Python 3.6 support."""
+        package_version = PackageVersion(
+            name="pandas", version=f"=={pandas_version}", develop=False, index=Source("https://pypi.org/simple"),
+        )
+
+        context = flexmock()
+        unit = PandasPy36Drop()
+        unit.pre_run()
+        with PandasPy36Drop.assigned_context(context):
+            assert unit._message_logged is False
+            assert list(unit.run(p for p in [package_version])) == []
+            assert unit._message_logged is True
+
+    def test_no_filter(self) -> None:
+        """Test not filtering packages that can be included."""
+        pkg1 = PackageVersion(name="pandas", version="==1.1.2", develop=False, index=Source("https://pypi.org/simple"),)
+        pkg2 = PackageVersion(name="pandas", version="==1.0.0", develop=False, index=Source("https://pypi.org/simple"),)
+        pkg3 = PackageVersion(
+            name="pandas", version="==0.24.2", develop=False, index=Source("https://pypi.org/simple"),
+        )
+
+        pkgs = [pkg1, pkg2, pkg3]
+
+        context = flexmock()
+        unit = PandasPy36Drop()
+        unit.pre_run()
+        with PandasPy36Drop.assigned_context(context):
+            assert unit._message_logged is False
+            assert list(unit.run(p for p in pkgs)) == pkgs
+            assert unit._message_logged is False

thoth/adviser/sieves/__init__.py

@@ -18,19 +18,20 @@
 """Implementation of sieves used in adviser pipeline."""
 
 from .abi_compat import AbiCompatibilitySieve
-from .filter_index import FilterIndexSieve
-from .index_enabled import PackageIndexSieve
-from .locked import CutLockedSieve
-from .prereleases import CutPreReleasesSieve
-from .solved import SolvedSieve
-from .version_constraint import VersionConstraintSieve
 from .backports import Enum34BackportSieve
 from .backports import Functools32BackportSieve
 from .backports import ImportlibMetadataBackportSieve
 from .backports import ImportlibResourcesBackportSieve
 from .backports import MockBackportSieve
-from .tensorflow import TensorFlowCUDASieve
+from .filter_index import FilterIndexSieve
+from .index_enabled import PackageIndexSieve
+from .locked import CutLockedSieve
+from .pandas import PandasPy36Drop
+from .prereleases import CutPreReleasesSieve
 from .setuptools import Py36SetuptoolsSieve
+from .solved import SolvedSieve
+from .tensorflow import TensorFlowCUDASieve
+from .version_constraint import VersionConstraintSieve
 
 
 # Relative ordering of units is relevant, as the order specifies order
@@ -51,4 +52,5 @@
     "MockBackportSieve",
     "Py36SetuptoolsSieve",
     "TensorFlowCUDASieve",
+    "PandasPy36Drop",
 ]

thoth/adviser/sieves/pandas/__init__.py

@@ -0,0 +1,25 @@
+#!/usr/bin/env python3
+# thoth-adviser
+# Copyright(C) 2020 Fridolin Pokorny
+#
+# This program is free software: you can redistribute it and / or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+"""Implementation of sieves used, specific for Pandas package."""
+
+from .py36_drop import PandasPy36Drop
+
+
+__all__ = [
+    "PandasPy36Drop",
+]

thoth/adviser/sieves/pandas/py36_drop.py

@@ -0,0 +1,79 @@
+#!/usr/bin/env python3
+# thoth-adviser
+# Copyright(C) 2020 Fridolin Pokorny
+#
+# This program is free software: you can redistribute it and / or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+"""Sieve Pandas>=1.2 on Python 3.6 as Pandas>=1.2 dropped Python 3.6 support."""
+
+import attr
+from typing import Any
+from typing import Optional
+from typing import Generator
+from typing import Dict
+from typing import TYPE_CHECKING
+import logging
+
+from thoth.common import get_justification_link as jl
+from thoth.python import PackageVersion
+
+from ...enums import RecommendationType
+from ...sieve import Sieve
+
+
+if TYPE_CHECKING:
+    from ..pipeline_builder import PipelineBuilderContext
+
+
+_LOGGER = logging.getLogger(__name__)
+
+
+@attr.s(slots=True)
+class PandasPy36Drop(Sieve):
+    """A sieve that makes sure Pandas>=1.2 is not used on Python 3.6 or older.
+
+    See https://github.com/pandas-dev/pandas/pull/35214
+    """
+
+    _MESSAGE = f"Pandas in versions >=1.2 dropped Python 3.6 support - see {jl('pandas_py36_drop')}"
+
+    _message_logged = attr.ib(type=bool, default=False, init=False)
+
+    def pre_run(self) -> None:
+        """Initialize this pipeline unit before each run."""
+        self._message_logged = False
+
+    @classmethod
+    def should_include(cls, builder_context: "PipelineBuilderContext") -> Optional[Dict[str, Any]]:
+        """Register this pipeline unit for adviser when Python 3.6 is used, not latest/testing recommendations."""
+        if not builder_context.is_adviser_pipeline() or builder_context.is_included(cls):
+            return None
+
+        if builder_context.recommendation_type in (RecommendationType.LATEST, RecommendationType.TESTING):
+            return None
+
+        if builder_context.project.runtime_environment.get_python_version_tuple() > (3, 6):
+            # Not a Python 3.6 or older environment.
+            return None
+
+        return {}
+
+    def run(self, package_versions: Generator[PackageVersion, None, None]) -> Generator[PackageVersion, None, None]:
+        """Do not use Pandas>=1.2 on Python 3.6."""
+        for package_version in package_versions:
+            if package_version.name != "pandas" or package_version.semantic_version.release[:2] < (1, 2):
+                yield package_version
+            elif not self._message_logged:
+                self._message_logged = True
+                _LOGGER.warning(self._MESSAGE)