Work around unionai-oss/pandera#1656

- Convert AttributeError to ImportError.
- Use pytest.importorskip() per the ImportError.
- Create genno.testing.MARK and apply to affected tests.

.pre-commit-config.yaml

@@ -7,6 +7,7 @@ repos:
     - importlib_resources
     - lxml-stubs
     - nbclient
+    - matplotlib
     - pint
     - pytest
     - sdmx1

genno/compat/pyam/operator.py

@@ -13,7 +13,12 @@
 )
 from warnings import warn
 
-import pyam
+try:
+    import pyam
+except AttributeError as e:
+    # https://github.com/unionai-oss/pandera/issues/1656 via pyam-iamc and ixmp4.
+    # Convert AttributeError to ImportError
+    raise ImportError("pandera") from e
 
 import genno
 import genno.operator

genno/testing/__init__.py

@@ -3,6 +3,7 @@
 import sys
 from contextlib import nullcontext
 from functools import partial
+from importlib.metadata import version
 from itertools import chain, islice
 from typing import TYPE_CHECKING, ContextManager, Dict
 
@@ -33,6 +34,16 @@
 
 log = logging.getLogger(__name__)
 
+# Common marks
+
+MARK = {
+    0: pytest.mark.xfail(
+        condition=version("numpy") > "2",
+        reason="https://github.com/unionai-oss/pandera/issues/1656 via pyam-iamc/ixmp4",
+    )
+}
+
+
 # Pytest hooks
 
 

genno/tests/compat/test_compat.py

@@ -1,3 +1,9 @@
+from genno.testing import MARK
+
+MARK_0 = MARK[0]  # py38 compatibility
+
+
+@MARK_0
 def test_import_pyam():
     """.compat.pyam.operator is populated only if pyam itself is installed.
 

genno/tests/compat/test_pyam.py

@@ -9,14 +9,18 @@
 from pandas.testing import assert_frame_equal, assert_series_equal
 
 from genno import Computer, Key, Quantity
-from genno.compat.pyam import operator, util
+from genno.compat.pyam import util
 from genno.operator import add, load_file
 from genno.testing import assert_logs, assert_units
 
 if TYPE_CHECKING:
     import pathlib
 
-# Skip this entire file if pyam is not installed
+# Skip this entire file if pyam is not installed or cannot be imported
+operator = pytest.importorskip(
+    "genno.compat.pyam.operator",
+    reason="https://github.com/unionai-oss/pandera/issues/1656 via pyam-iamc/ixmp4",
+)
 pyam = pytest.importorskip("pyam", reason="pyam-iamc not installed")
 
 # Warning emitted by pandas ≥ 2.1.0 with pyam 1.9.0