34185: fix doctest failure + pep8 fixes

src/sage/doctest/control.py

@@ -1364,7 +1364,7 @@ def run(self):
             sage: DC = DocTestController(DF, [filename])
             sage: DC.run()
             Running doctests with ID ...
-            Using --optional=sage
+            Using --optional=sage...
             Features to be detected: ...
             Doctesting 1 file.
             sage -t ....py
@@ -1556,28 +1556,28 @@ def stringify(x):
 # Declaration of doctest strings
 ###############################################################################
 
-test_hide=r"""{}
-sage: next(graphs.fullerenes(20))
+test_hide=r"""r{quotmark}
+{prompt}: next(graphs.fullerenes(20))
 Traceback (most recent call last):
  ...
 FeatureNotPresentError: buckygen is not available.
 ...
-sage: next(graphs.fullerenes(20))   # optional buckygen
+{prompt}: next(graphs.fullerenes(20))   # optional buckygen
 Graph on 20 vertices
 
-sage: len(list(graphs.fusenes(2)))
+{prompt}: len(list(graphs.fusenes(2)))
 Traceback (most recent call last):
  ...
 FeatureNotPresentError: benzene is not available.
 ...
-sage: len(list(graphs.fusenes(2)))  # optional benzene
+{prompt}: len(list(graphs.fusenes(2)))  # optional benzene
 1
-sage: from sage.matrix.matrix_space import get_matrix_class
-sage: get_matrix_class(GF(25,'x'), 4, 4, False, 'meataxe')
+{prompt}: from sage.matrix.matrix_space import get_matrix_class
+{prompt}: get_matrix_class(GF(25,'x'), 4, 4, False, 'meataxe')
 Failed lazy import:
 sage.matrix.matrix_gfpn_dense is not available.
 ...
-sage: get_matrix_class(GF(25,'x'), 4, 4, False, 'meataxe') # optional meataxe
+{prompt}: get_matrix_class(GF(25,'x'), 4, 4, False, 'meataxe') # optional meataxe
 <class 'sage.matrix.matrix_gfpn_dense.Matrix_gfpn_dense'>
-{}
-""".format('r"""', '"""')
+{quotmark}
+""".format(quotmark='"""', prompt='sage')  # using prompt to hide these lines from _test_enough_doctests

src/sage/features/__init__.py

@@ -74,8 +74,10 @@ def __call__(cls, *args, **kwds):
         else:
             return type.__call__(cls, *args, **kwds)
 
+
 _trivial_unique_representation_cache = dict()
 
+
 class TrivialUniqueRepresentation(metaclass=TrivialClasscallMetaClass):
     r"""
     A trivial version of :class:`UniqueRepresentation` without Cython dependencies.
@@ -92,6 +94,7 @@ def __classcall__(cls, *args, **options):
             cached = _trivial_unique_representation_cache[key] = type.__call__(cls, *args, **options)
         return cached
 
+
 class Feature(TrivialUniqueRepresentation):
     r"""
     A feature of the runtime environment
@@ -244,7 +247,10 @@ def _spkg_type(self):
         If no SPKG corresponds to this feature ``None`` is returned.
         """
         from sage.misc.package import _spkg_type
-        return _spkg_type(self.name)
+        spkg = self.spkg
+        if not spkg:
+            spkg = self.name
+        return _spkg_type(spkg)
 
     def resolution(self):
         r"""
@@ -379,8 +385,6 @@ def unhide(self):
         self._hidden = False
 
 
-
-
 class FeatureNotPresentError(RuntimeError):
     r"""
     A missing feature error.
@@ -499,8 +503,6 @@ def __bool__(self):
         """
         return bool(self.is_present)
 
-
-
     def __repr__(self):
         r"""
         TESTS::
@@ -514,6 +516,7 @@ def __repr__(self):
 
 _cache_package_systems = None
 
+
 def package_systems():
     """
     Return a list of :class:`~sage.features.pkg_systems.PackageSystem` objects
@@ -799,7 +802,9 @@ def absolute_filename(self) -> str:
         A :class:`FeatureNotPresentError` is raised if the file cannot be found::
 
             sage: from sage.features import StaticFile
-            sage: StaticFile(name="no_such_file", filename="KaT1aihu", search_path=(), spkg="some_spkg", url="http://rand.om").absolute_filename()  # optional - sage_spkg
+            sage: StaticFile(name="no_such_file", filename="KaT1aihu",\
+                             search_path=(), spkg="some_spkg",\
+                             url="http://rand.om").absolute_filename()  # optional - sage_spkg
             Traceback (most recent call last):
             ...
             FeatureNotPresentError: no_such_file is not available.
@@ -811,9 +816,8 @@ def absolute_filename(self) -> str:
             path = os.path.join(directory, self.filename)
             if os.path.isfile(path) or os.path.isdir(path):
                 return os.path.abspath(path)
-        raise FeatureNotPresentError(self,
-            reason="{filename!r} not found in any of {search_path}".format(filename=self.filename, search_path=self.search_path),
-            resolution=self.resolution())
+        reason = "{filename!r} not found in any of {search_path}".format(filename=self.filename, search_path=self.search_path)
+        raise FeatureNotPresentError(self, reason=reason, resolution=self.resolution())
 
 
 class CythonFeature(Feature):