ENH: Add pytest_extra_requires to conditionally ignore paths / skip functions unless requirements are met

scipy_doctest/impl.py

@@ -79,7 +79,7 @@ class DTConfig:
         Default is False.
     pytest_extra_ignore : list
         A list of names/modules to ignore when run under pytest plugin. This is
-        equivalent to using `--ignore=...` cmdline switch.
+        equivalent to using ``--ignore=...`` cmdline switch.
     pytest_extra_skip : dict
         Names/modules to skip when run under pytest plugin. This is
         equivalent to decorating the doctest with `@pytest.mark.skip` or adding
@@ -92,6 +92,12 @@ class DTConfig:
         adding `# may vary` to the outputs of all examples.
         Each key is a doctest name to skip, and the corresponding value is
         a string. If not empty, the string value is used as the skip reason.
+    pytest_extra_requires : dict
+        Paths or functions to conditionally ignore unless requirements are met.
+        The format is ``{path/or/glob/pattern: requirement, full.func.name: requiremet}``,
+        where the values are PEP 508 dependency specifiers. If a requirement is not met,
+        the behavior is equivalent to using the ``--ignore=...`` command line switch for
+        paths, and to using a `pytest_extra_skip` for function names.
     CheckerKlass : object, optional
         The class for the Checker object. Must mimic the ``DTChecker`` API:
         subclass the `doctest.OutputChecker` and make the constructor signature
@@ -125,6 +131,7 @@ def __init__(self, *, # DTChecker configuration
                           pytest_extra_ignore=None,
                           pytest_extra_skip=None,
                           pytest_extra_xfail=None,
+                          pytest_extra_requires=None,
     ):
         ### DTChecker configuration ###
         self.CheckerKlass = CheckerKlass or DTChecker
@@ -217,6 +224,7 @@ def __init__(self, *, # DTChecker configuration
         self.pytest_extra_ignore = pytest_extra_ignore or []
         self.pytest_extra_skip = pytest_extra_skip or {}
         self.pytest_extra_xfail = pytest_extra_xfail or {}
+        self.pytest_extra_requires = pytest_extra_requires or {}
 
 
 def try_convert_namedtuple(got):

scipy_doctest/plugin.py

@@ -13,7 +13,7 @@
 
 from .impl import DTParser, DebugDTRunner
 from .conftest import dt_config
-from .util import np_errstate, matplotlib_make_nongui, temp_cwd
+from .util import np_errstate, matplotlib_make_nongui, temp_cwd, is_req_satisfied
 from .frontend import find_doctests
 
 
@@ -82,10 +82,16 @@ def pytest_ignore_collect(collection_path, config):
         if "tests" in path_str or "test_" in path_str:
             return True
 
+    fnmatch_ex = _pytest.pathlib.fnmatch_ex
+
     for entry in config.dt_config.pytest_extra_ignore:
-        if entry in str(collection_path):
+        if fnmatch_ex(entry, collection_path):
             return True
 
+    for entry, req_str in config.dt_config.pytest_extra_requires.items():
+        if fnmatch_ex(entry, collection_path):
+            return not is_req_satisfied(req_str)
+
 
 def is_private(item):
     """Decide if an DocTestItem `item` is private.
@@ -125,6 +131,13 @@ def _maybe_add_markers(item, config):
             pytest.mark.xfail(reason=reason)
         )
 
+    extra_requires = dt_config.pytest_extra_requires
+    if req_str := extra_requires.get(item.name, None):
+        if not is_req_satisfied(req_str):
+            item.add_marker(
+                pytest.mark.skip(reason=f"requires {req_str}")
+            )
+
 
 def pytest_collection_modifyitems(config, items):
     """

scipy_doctest/util.py

@@ -10,6 +10,8 @@
 import inspect
 from contextlib import contextmanager
 
+from importlib.metadata import version as get_version, PackageNotFoundError
+from packaging.requirements import Requirement
 
 @contextmanager
 def matplotlib_make_nongui():
@@ -255,6 +257,16 @@ def get_public_objects(module, skiplist=None):
     return (items, names), failures
 
 
+def is_req_satisfied(req_str):
+    """ Check if a PEP 508-compliant requirement is satisfied or not.
+    """
+    req = Requirement(req_str)
+    try:
+        return get_version(req.name) in req.specifier
+    except PackageNotFoundError:
+        return False
+
+
 # XXX: not used ATM
 modules = []
 def generate_log(module, test):