Issue #15641: Clean up deprecated classes from importlib

Patch by Taras Lyapun.

Doc/library/importlib.rst

@@ -133,8 +133,6 @@ ABC hierarchy::
                +-- ExecutionLoader --+
                                      +-- FileLoader
                                      +-- SourceLoader
-                                          +-- PyLoader (deprecated)
-                                          +-- PyPycLoader (deprecated)
 
 
 .. class:: Finder
@@ -431,142 +429,6 @@ ABC hierarchy::
         itself does not end in ``__init__``.
 
 
-.. class:: PyLoader
-
-    An abstract base class inheriting from
-    :class:`ExecutionLoader` and
-    :class:`ResourceLoader` designed to ease the loading of
-    Python source modules (bytecode is not handled; see
-    :class:`SourceLoader` for a source/bytecode ABC). A subclass
-    implementing this ABC will only need to worry about exposing how the source
-    code is stored; all other details for loading Python source code will be
-    handled by the concrete implementations of key methods.
-
-    .. deprecated:: 3.2
-        This class has been deprecated in favor of :class:`SourceLoader` and is
-        slated for removal in Python 3.4. See below for how to create a
-        subclass that is compatible with Python 3.1 onwards.
-
-    If compatibility with Python 3.1 is required, then use the following idiom
-    to implement a subclass that will work with Python 3.1 onwards (make sure
-    to implement :meth:`ExecutionLoader.get_filename`)::
-
-        try:
-            from importlib.abc import SourceLoader
-        except ImportError:
-            from importlib.abc import PyLoader as SourceLoader
-
-
-        class CustomLoader(SourceLoader):
-            def get_filename(self, fullname):
-                """Return the path to the source file."""
-                # Implement ...
-
-            def source_path(self, fullname):
-                """Implement source_path in terms of get_filename."""
-                try:
-                    return self.get_filename(fullname)
-                except ImportError:
-                    return None
-
-            def is_package(self, fullname):
-                """Implement is_package by looking for an __init__ file
-                name as returned by get_filename."""
-                filename = os.path.basename(self.get_filename(fullname))
-                return os.path.splitext(filename)[0] == '__init__'
-
-
-    .. method:: source_path(fullname)
-
-        An abstract method that returns the path to the source code for a
-        module. Should return ``None`` if there is no source code.
-        Raises :exc:`ImportError` if the loader knows it cannot handle the
-        module.
-
-    .. method:: get_filename(fullname)
-
-        A concrete implementation of
-        :meth:`importlib.abc.ExecutionLoader.get_filename` that
-        relies on :meth:`source_path`. If :meth:`source_path` returns
-        ``None``, then :exc:`ImportError` is raised.
-
-    .. method:: load_module(fullname)
-
-        A concrete implementation of :meth:`importlib.abc.Loader.load_module`
-        that loads Python source code. All needed information comes from the
-        abstract methods required by this ABC. The only pertinent assumption
-        made by this method is that when loading a package
-        :attr:`__path__` is set to ``[os.path.dirname(__file__)]``.
-
-    .. method:: get_code(fullname)
-
-        A concrete implementation of
-        :meth:`importlib.abc.InspectLoader.get_code` that creates code objects
-        from Python source code, by requesting the source code (using
-        :meth:`source_path` and :meth:`get_data`) and compiling it with the
-        built-in :func:`compile` function.
-
-    .. method:: get_source(fullname)
-
-        A concrete implementation of
-        :meth:`importlib.abc.InspectLoader.get_source`. Uses
-        :meth:`importlib.abc.ResourceLoader.get_data` and :meth:`source_path`
-        to get the source code.  It tries to guess the source encoding using
-        :func:`tokenize.detect_encoding`.
-
-
-.. class:: PyPycLoader
-
-    An abstract base class inheriting from :class:`PyLoader`.
-    This ABC is meant to help in creating loaders that support both Python
-    source and bytecode.
-
-    .. deprecated:: 3.2
-        This class has been deprecated in favor of :class:`SourceLoader` and to
-        properly support :pep:`3147`. If compatibility is required with
-        Python 3.1, implement both :class:`SourceLoader` and :class:`PyLoader`;
-        instructions on how to do so are included in the documentation for
-        :class:`PyLoader`. Do note that this solution will not support
-        sourceless/bytecode-only loading; only source *and* bytecode loading.
-
-    .. versionchanged:: 3.3
-       Updated to parse (but not use) the new source size field in bytecode
-       files when reading and to write out the field properly when writing.
-
-    .. method:: source_mtime(fullname)
-
-        An abstract method which returns the modification time for the source
-        code of the specified module. The modification time should be an
-        integer. If there is no source code, return ``None``. If the
-        module cannot be found then :exc:`ImportError` is raised.
-
-    .. method:: bytecode_path(fullname)
-
-        An abstract method which returns the path to the bytecode for the
-        specified module, if it exists. It returns ``None``
-        if no bytecode exists (yet).
-        Raises :exc:`ImportError` if the loader knows it cannot handle the
-        module.
-
-    .. method:: get_filename(fullname)
-
-        A concrete implementation of
-        :meth:`ExecutionLoader.get_filename` that relies on
-        :meth:`PyLoader.source_path` and :meth:`bytecode_path`.
-        If :meth:`source_path` returns a path, then that value is returned.
-        Else if :meth:`bytecode_path` returns a path, that path will be
-        returned. If a path is not available from both methods,
-        :exc:`ImportError` is raised.
-
-    .. method:: write_bytecode(fullname, bytecode)
-
-        An abstract method which has the loader write *bytecode* for future
-        use. If the bytecode is written, return ``True``. Return
-        ``False`` if the bytecode could not be written. This method
-        should not be called if :data:`sys.dont_write_bytecode` is true.
-        The *bytecode* argument should be a bytes string or bytes array.
-
-
 :mod:`importlib.machinery` -- Importers and path hooks
 ------------------------------------------------------
 

Lib/importlib/abc.py

@@ -225,180 +225,3 @@ class SourceLoader(_bootstrap.SourceLoader, ResourceLoader, ExecutionLoader):
         raise NotImplementedError
 
 _register(SourceLoader, machinery.SourceFileLoader)
-
-class PyLoader(SourceLoader):
-
-    """Implement the deprecated PyLoader ABC in terms of SourceLoader.
-
-    This class has been deprecated! It is slated for removal in Python 3.4.
-    If compatibility with Python 3.1 is not needed then implement the
-    SourceLoader ABC instead of this class. If Python 3.1 compatibility is
-    needed, then use the following idiom to have a single class that is
-    compatible with Python 3.1 onwards::
-
-        try:
-            from importlib.abc import SourceLoader
-        except ImportError:
-            from importlib.abc import PyLoader as SourceLoader
-
-
-        class CustomLoader(SourceLoader):
-            def get_filename(self, fullname):
-                # Implement ...
-
-            def source_path(self, fullname):
-                '''Implement source_path in terms of get_filename.'''
-                try:
-                    return self.get_filename(fullname)
-                except ImportError:
-                    return None
-
-            def is_package(self, fullname):
-                filename = os.path.basename(self.get_filename(fullname))
-                return os.path.splitext(filename)[0] == '__init__'
-
-    """
-
-    @abc.abstractmethod
-    def is_package(self, fullname):
-        raise NotImplementedError
-
-    @abc.abstractmethod
-    def source_path(self, fullname):
-        """Abstract method.  Accepts a str module name and returns the path to
-        the source code for the module."""
-        raise NotImplementedError
-
-    def get_filename(self, fullname):
-        """Implement get_filename in terms of source_path.
-
-        As get_filename should only return a source file path there is no
-        chance of the path not existing but loading still being possible, so
-        ImportError should propagate instead of being turned into returning
-        None.
-
-        """
-        warnings.warn("importlib.abc.PyLoader is deprecated and is "
-                            "slated for removal in Python 3.4; "
-                            "use SourceLoader instead. "
-                            "See the importlib documentation on how to be "
-                            "compatible with Python 3.1 onwards.",
-                        DeprecationWarning)
-        path = self.source_path(fullname)
-        if path is None:
-            raise ImportError(name=fullname)
-        else:
-            return path
-
-
-class PyPycLoader(PyLoader):
-
-    """Abstract base class to assist in loading source and bytecode by
-    requiring only back-end storage methods to be implemented.
-
-    This class has been deprecated! Removal is slated for Python 3.4. Implement
-    the SourceLoader ABC instead. If Python 3.1 compatibility is needed, see
-    PyLoader.
-
-    The methods get_code, get_source, and load_module are implemented for the
-    user.
-
-    """
-
-    def get_filename(self, fullname):
-        """Return the source or bytecode file path."""
-        path = self.source_path(fullname)
-        if path is not None:
-            return path
-        path = self.bytecode_path(fullname)
-        if path is not None:
-            return path
-        raise ImportError("no source or bytecode path available for "
-                            "{0!r}".format(fullname), name=fullname)
-
-    def get_code(self, fullname):
-        """Get a code object from source or bytecode."""
-        warnings.warn("importlib.abc.PyPycLoader is deprecated and slated for "
-                            "removal in Python 3.4; use SourceLoader instead. "
-                            "If Python 3.1 compatibility is required, see the "
-                            "latest documentation for PyLoader.",
-                        DeprecationWarning)
-        source_timestamp = self.source_mtime(fullname)
-        # Try to use bytecode if it is available.
-        bytecode_path = self.bytecode_path(fullname)
-        if bytecode_path:
-            data = self.get_data(bytecode_path)
-            try:
-                magic = data[:4]
-                if len(magic) < 4:
-                    raise ImportError(
-                        "bad magic number in {}".format(fullname),
-                        name=fullname, path=bytecode_path)
-                raw_timestamp = data[4:8]
-                if len(raw_timestamp) < 4:
-                    raise EOFError("bad timestamp in {}".format(fullname))
-                pyc_timestamp = _bootstrap._r_long(raw_timestamp)
-                raw_source_size = data[8:12]
-                if len(raw_source_size) != 4:
-                    raise EOFError("bad file size in {}".format(fullname))
-                # Source size is unused as the ABC does not provide a way to
-                # get the size of the source ahead of reading it.
-                bytecode = data[12:]
-                # Verify that the magic number is valid.
-                if imp.get_magic() != magic:
-                    raise ImportError(
-                        "bad magic number in {}".format(fullname),
-                        name=fullname, path=bytecode_path)
-                # Verify that the bytecode is not stale (only matters when
-                # there is source to fall back on.
-                if source_timestamp:
-                    if pyc_timestamp < source_timestamp:
-                        raise ImportError("bytecode is stale", name=fullname,
-                                          path=bytecode_path)
-            except (ImportError, EOFError):
-                # If source is available give it a shot.
-                if source_timestamp is not None:
-                    pass
-                else:
-                    raise
-            else:
-                # Bytecode seems fine, so try to use it.
-                return marshal.loads(bytecode)
-        elif source_timestamp is None:
-            raise ImportError("no source or bytecode available to create code "
-                              "object for {0!r}".format(fullname),
-                              name=fullname)
-        # Use the source.
-        source_path = self.source_path(fullname)
-        if source_path is None:
-            message = "a source path must exist to load {0}".format(fullname)
-            raise ImportError(message, name=fullname)
-        source = self.get_data(source_path)
-        code_object = compile(source, source_path, 'exec', dont_inherit=True)
-        # Generate bytecode and write it out.
-        if not sys.dont_write_bytecode:
-            data = bytearray(imp.get_magic())
-            data.extend(_bootstrap._w_long(source_timestamp))
-            data.extend(_bootstrap._w_long(len(source) & 0xFFFFFFFF))
-            data.extend(marshal.dumps(code_object))
-            self.write_bytecode(fullname, data)
-        return code_object
-
-    @abc.abstractmethod
-    def source_mtime(self, fullname):
-        """Abstract method. Accepts a str filename and returns an int
-        modification time for the source of the module."""
-        raise NotImplementedError
-
-    @abc.abstractmethod
-    def bytecode_path(self, fullname):
-        """Abstract method. Accepts a str filename and returns the str pathname
-        to the bytecode for the module."""
-        raise NotImplementedError
-
-    @abc.abstractmethod
-    def write_bytecode(self, fullname, bytecode):
-        """Abstract method.  Accepts a str filename and bytes object
-        representing the bytecode for the module.  Returns a boolean
-        representing whether the bytecode was written or not."""
-        raise NotImplementedError

Lib/test/test_importlib/test_abc.py

@@ -43,11 +43,6 @@ class PathEntryFinder(InheritanceTests, unittest.TestCase):
     subclasses = [machinery.FileFinder]
 
 
-class Loader(InheritanceTests, unittest.TestCase):
-
-    subclasses = [abc.PyLoader]
-
-
 class ResourceLoader(InheritanceTests, unittest.TestCase):
 
     superclasses = [abc.Loader]
@@ -56,14 +51,13 @@ class ResourceLoader(InheritanceTests, unittest.TestCase):
 class InspectLoader(InheritanceTests, unittest.TestCase):
 
     superclasses = [abc.Loader]
-    subclasses = [abc.PyLoader, machinery.BuiltinImporter,
+    subclasses = [machinery.BuiltinImporter,
                     machinery.FrozenImporter, machinery.ExtensionFileLoader]
 
 
 class ExecutionLoader(InheritanceTests, unittest.TestCase):
 
     superclasses = [abc.InspectLoader]
-    subclasses = [abc.PyLoader]
 
 
 class FileLoader(InheritanceTests, unittest.TestCase):
@@ -78,16 +72,6 @@ class SourceLoader(InheritanceTests, unittest.TestCase):
     subclasses = [machinery.SourceFileLoader]
 
 
-class PyLoader(InheritanceTests, unittest.TestCase):
-
-    superclasses = [abc.Loader, abc.ResourceLoader, abc.ExecutionLoader]
-
-
-class PyPycLoader(InheritanceTests, unittest.TestCase):
-
-    superclasses = [abc.PyLoader]
-
-
 def test_main():
     from test.support import run_unittest
     classes = []

Misc/NEWS

@@ -107,6 +107,9 @@ Core and Builtins
 Library
 -------
 
+- Issue #15641: Clean up deprecated classes from importlib
+  Patch by Taras Lyapun.
+
 - Issue #16350: zlib.Decompress.decompress() now accumulates data from
   successive calls after EOF in unused_data, instead of only saving the argument
   to the last call. Patch by Serhiy Storchaka.