Mostly as a note to myself (although if someone else wants to change this, then great), PathEntryFinder.find_loader() specifies self while the other docs don't bother to list it.
And I just realized that the other classes defined in the importlib docs don't list their superclasses like MetaPathFinder and PathEntryFinder now do. On Thu, Aug 2, 2012 at 7:26 AM, nick.coghlan <python-check...@python.org>wrote: > http://hg.python.org/cpython/rev/184700df5b6a > changeset: 78379:184700df5b6a > parent: 78376:8ace059cdffd > user: Nick Coghlan <ncogh...@gmail.com> > date: Thu Aug 02 21:26:03 2012 +1000 > summary: > Issue #15502: Bring the importlib ABCs into line with the current state > of the import protocols given PEP 420. Original patch by Eric Snow. > > files: > Doc/library/importlib.rst | 77 +++++--- > Lib/importlib/abc.py | 82 ++++++--- > Lib/test/test_importlib/source/test_abc_loader.py | 23 +- > Lib/test/test_importlib/test_abc.py | 7 +- > Misc/NEWS | 3 + > 5 files changed, 127 insertions(+), 65 deletions(-) > > > diff --git a/Doc/library/importlib.rst b/Doc/library/importlib.rst > --- a/Doc/library/importlib.rst > +++ b/Doc/library/importlib.rst > @@ -125,32 +125,49 @@ > > .. class:: Finder > > - An abstract base class representing a :term:`finder`. > - See :pep:`302` for the exact definition for a finder. > - > - .. method:: find_loader(self, fullname): > - > - An abstract method for finding a :term:`loader` for the specified > - module. Returns a 2-tuple of ``(loader, portion)`` where portion > is a > - sequence of file system locations contributing to part of a > namespace > - package. The sequence may be empty. When present, > `find_loader()` is > - preferred over `find_module()`. > - > - .. versionadded: 3.3 > - > - .. method:: find_module(fullname, path=None) > - > - An abstract method for finding a :term:`loader` for the specified > - module. If the :term:`finder` is found on :data:`sys.meta_path` > and the > - module to be searched for is a subpackage or module then *path* > will > - be the value of :attr:`__path__` from the parent package. If a > loader > - cannot be found, ``None`` is returned. > + An abstract base class representing a :term:`finder`. Finder > + implementations should derive from (or register with) the more specific > + :class:`MetaPathFinder` or :class:`PathEntryFinder` ABCs. > > .. method:: invalidate_caches() > > - An optional method which, when called, should invalidate any > internal > - cache used by the finder. Used by :func:`invalidate_caches()` when > - invalidating the caches of all cached finders. > + An optional method which, when called, should invalidate any > internal > + cache used by the finder. Used by :func:`invalidate_caches()` when > + invalidating the caches of all cached finders. > + > + .. versionchanged:: 3.3 > + The API signatures for meta path finders and path entry finders > + were separated by PEP 420. Accordingly, the Finder ABC no > + longer requires implementation of a ``find_module()`` method. > + > + > +.. class:: MetaPathFinder(Finder) > + > + An abstract base class representing a :term:`meta path finder`. > + > + .. versionadded:: 3.3 > + > + .. method:: find_module(fullname, path) > + > + An abstract method for finding a :term:`loader` for the specified > + module. If this is a top-level import, *path* will be ``None``. > + Otheriwse, this is a search for a subpackage or module and *path* > + will be the value of :attr:`__path__` from the parent > + package. If a loader cannot be found, ``None`` is returned. > + > + > +.. class:: PathEntryFinder(Finder) > + > + An abstract base class representing a :term:`path entry finder`. > + > + .. versionadded:: 3.3 > + > + .. method:: find_loader(self, fullname): > + > + An abstract method for finding a :term:`loader` for the specified > + module. Returns a 2-tuple of ``(loader, portion)`` where portion > is a > + sequence of file system locations contributing to part of a > namespace > + package. The sequence may be empty. > > > .. class:: Loader > @@ -569,8 +586,8 @@ > > An :term:`importer` for built-in modules. All known built-in modules > are > listed in :data:`sys.builtin_module_names`. This class implements the > - :class:`importlib.abc.Finder` and :class:`importlib.abc.InspectLoader` > - ABCs. > + :class:`importlib.abc.MetaPathFinder` and > + :class:`importlib.abc.InspectLoader` ABCs. > > Only class methods are defined by this class to alleviate the need for > instantiation. > @@ -579,8 +596,8 @@ > .. class:: FrozenImporter > > An :term:`importer` for frozen modules. This class implements the > - :class:`importlib.abc.Finder` and :class:`importlib.abc.InspectLoader` > - ABCs. > + :class:`importlib.abc.MetaPathFinder` and > + :class:`importlib.abc.InspectLoader` ABCs. > > Only class methods are defined by this class to alleviate the need for > instantiation. > @@ -589,7 +606,7 @@ > .. class:: PathFinder > > :term:`Finder` for :data:`sys.path`. This class implements the > - :class:`importlib.abc.Finder` ABC. > + :class:`importlib.abc.MetaPathFinder` ABC. > > This class does not perfectly mirror the semantics of > :keyword:`import` in > terms of :data:`sys.path`. No implicit path hooks are assumed for > @@ -616,8 +633,8 @@ > > .. class:: FileFinder(path, \*loader_details) > > - A concrete implementation of :class:`importlib.abc.Finder` which caches > - results from the file system. > + A concrete implementation of :class:`importlib.abc.PathEntryFinder` > which > + caches results from the file system. > > The *path* argument is the directory for which the finder is in charge > of > searching. > diff --git a/Lib/importlib/abc.py b/Lib/importlib/abc.py > --- a/Lib/importlib/abc.py > +++ b/Lib/importlib/abc.py > @@ -23,6 +23,61 @@ > abstract_cls.register(frozen_cls) > > > +class Finder(metaclass=abc.ABCMeta): > + > + """Common abstract base class for import finders. > + > + Finder implementations should derive from the more specific > + MetaPathFinder or PathEntryFinder ABCs rather than directly from > Finder. > + """ > + > + def find_module(self, fullname, path=None): > + """An optional legacy method that should find a module. > + The fullname is a str and the optional path is a str or None. > + Returns a Loader object. > + > + The path finder will use this method only if find_loader() does > + not exist. It may optionally be implemented for compatibility > + with legacy third party reimplementations of the import system. > + """ > + raise NotImplementedError > + > + # invalidate_caches() is a completely optional method, so no default > + # implementation is provided. See the docs for details. > + > + > +class MetaPathFinder(Finder): > + > + """Abstract base class for import finders on sys.meta_path.""" > + > + @abc.abstractmethod > + def find_module(self, fullname, path): > + """Abstract method which when implemented should find a module. > + The fullname is a str and the path is a str or None. > + Returns a Loader object. > + """ > + raise NotImplementedError > + > +_register(MetaPathFinder, machinery.BuiltinImporter, > machinery.FrozenImporter, > + machinery.PathFinder) > + > + > +class PathEntryFinder(Finder): > + > + """Abstract base class for path entry finders used by PathFinder.""" > + > + @abc.abstractmethod > + def find_loader(self, fullname): > + """Abstract method which when implemented returns a module loader. > + The fullname is a str. Returns a 2-tuple of (Loader, portion) > where > + portion is a sequence of file system locations contributing to > part of > + a namespace package. The sequence may be empty. > + """ > + raise NotImplementedError > + > +_register(PathEntryFinder, machinery.FileFinder) > + > + > class Loader(metaclass=abc.ABCMeta): > > """Abstract base class for import loaders.""" > @@ -40,33 +95,6 @@ > raise NotImplementedError > > > -class Finder(metaclass=abc.ABCMeta): > - > - """Abstract base class for import finders.""" > - > - @abc.abstractmethod > - def find_loader(self, fullname): > - """Abstract method which when implemented returns a module loader. > - The fullname is a str. Returns a 2-tuple of (Loader, portion) > where > - portion is a sequence of file system locations contributing to > part of > - a namespace package. The sequence may be empty. When present, > - `find_loader()` is preferred over `find_module()`. > - """ > - raise NotImplementedError > - > - @abc.abstractmethod > - def find_module(self, fullname, path=None): > - """Abstract method which when implemented should find a module. > - The fullname is a str and the optional path is a str or None. > - Returns a Loader object. This method is only called if > - `find_loader()` is not present. > - """ > - raise NotImplementedError > - > -_register(Finder, machinery.BuiltinImporter, machinery.FrozenImporter, > - machinery.PathFinder, machinery.FileFinder) > - > - > class ResourceLoader(Loader): > > """Abstract base class for loaders which can return data from their > diff --git a/Lib/test/test_importlib/source/test_abc_loader.py > b/Lib/test/test_importlib/source/test_abc_loader.py > --- a/Lib/test/test_importlib/source/test_abc_loader.py > +++ b/Lib/test/test_importlib/source/test_abc_loader.py > @@ -778,23 +778,32 @@ > expect = io.IncrementalNewlineDecoder(None, True).decode(source) > self.assertEqual(mock.get_source(name), expect) > > + > class AbstractMethodImplTests(unittest.TestCase): > > """Test the concrete abstractmethod implementations.""" > > + class MetaPathFinder(abc.MetaPathFinder): > + def find_module(self, fullname, path): > + super().find_module(fullname, path) > + > + class PathEntryFinder(abc.PathEntryFinder): > + def find_module(self, _): > + super().find_module(_) > + > + def find_loader(self, _): > + super().find_loader(_) > + > + class Finder(abc.Finder): > + def find_module(self, fullname, path): > + super().find_module(fullname, path) > + > class Loader(abc.Loader): > def load_module(self, fullname): > super().load_module(fullname) > def module_repr(self, module): > super().module_repr(module) > > - class Finder(abc.Finder): > - def find_module(self, _): > - super().find_module(_) > - > - def find_loader(self, _): > - super().find_loader(_) > - > class ResourceLoader(Loader, abc.ResourceLoader): > def get_data(self, _): > super().get_data(_) > diff --git a/Lib/test/test_importlib/test_abc.py > b/Lib/test/test_importlib/test_abc.py > --- a/Lib/test/test_importlib/test_abc.py > +++ b/Lib/test/test_importlib/test_abc.py > @@ -30,11 +30,16 @@ > "{0} is not a superclass of {1}".format(superclass, > self.__test)) > > > -class Finder(InheritanceTests, unittest.TestCase): > +class MetaPathFinder(InheritanceTests, unittest.TestCase): > > + superclasses = [abc.Finder] > subclasses = [machinery.BuiltinImporter, machinery.FrozenImporter, > machinery.PathFinder] > > +class PathEntryFinder(InheritanceTests, unittest.TestCase): > + > + superclasses = [abc.Finder] > + subclasses = [machinery.FileFinder] > > class Loader(InheritanceTests, unittest.TestCase): > > diff --git a/Misc/NEWS b/Misc/NEWS > --- a/Misc/NEWS > +++ b/Misc/NEWS > @@ -72,6 +72,9 @@ > Library > ------- > > +- Issue #15502: Bring the importlib ABCs into line with the current state > + of the import protocols given PEP 420. Original patch by Eric Snow. > + > - Issue #15499: Launching a webbrowser in Unix used to sleep for a few > seconds. Original patch by Anton Barkovsky. > > > -- > Repository URL: http://hg.python.org/cpython > > _______________________________________________ > Python-checkins mailing list > python-check...@python.org > http://mail.python.org/mailman/listinfo/python-checkins > >
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