[Python-checkins] cpython: Issue #17117: Have both import itself and importlib.util.set_loader()

Wed Mar 13 18:45:47 CET 2013

http://hg.python.org/cpython/rev/7647aae9481c
changeset: 82643:7647aae9481c
user: Brett Cannon <brett at python.org>
date: Wed Mar 13 10:41:36 2013 -0700
summary:
 Issue #17117: Have both import itself and importlib.util.set_loader()
set __loader__ on a module when set to None.
Thanks to Gökcen Eraslan for the fix.
files:
 Doc/library/importlib.rst | 4 +
 Doc/reference/import.rst | 16 +-
 Lib/importlib/_bootstrap.py | 9 +-
 Lib/test/test_importlib/import_/test___loader__.py | 44 +
 Lib/test/test_importlib/test_util.py | 42 +-
 Misc/ACKS | 1 +
 Misc/NEWS | 3 +
 Python/importlib.h | 6699 ++++-----
 8 files changed, 3443 insertions(+), 3375 deletions(-)

diff --git a/Doc/library/importlib.rst b/Doc/library/importlib.rst
--- a/Doc/library/importlib.rst
+++ b/Doc/library/importlib.rst
@@ -774,6 +774,10 @@
 It is recommended that :func:`module_for_loader` be used over this
 decorator as it subsumes this functionality.
 
+ .. versionchanged:: 3.4
+ Set ``__loader__`` if set to ``None`` as well if the attribute does not
+ exist.
+
 
 .. decorator:: set_package
 
diff --git a/Doc/reference/import.rst b/Doc/reference/import.rst
--- a/Doc/reference/import.rst
+++ b/Doc/reference/import.rst
@@ -369,16 +369,18 @@
 * The ``__loader__`` attribute must be set to the loader object that loaded
 the module. This is mostly for introspection and reloading, but can be
 used for additional loader-specific functionality, for example getting
- data associated with a loader.
+ data associated with a loader. If the attribute is missing or set to ``None``
+ then the import machinery will automatically set it **after** the module has
+ been imported.
 
- * The module's ``__package__`` attribute should be set. Its value must be a
+ * The module's ``__package__`` attribute must be set. Its value must be a
 string, but it can be the same value as its ``__name__``. If the attribute
 is set to ``None`` or is missing, the import system will fill it in with a
- more appropriate value. When the module is a package, its ``__package__``
- value should be set to its ``__name__``. When the module is not a package,
- ``__package__`` should be set to the empty string for top-level modules, or
- for submodules, to the parent package's name. See :pep:`366` for further
- details.
+ more appropriate value **after** the module has been imported.
+ When the module is a package, its ``__package__`` value should be set to its
+ ``__name__``. When the module is not a package, ``__package__`` should be
+ set to the empty string for top-level modules, or for submodules, to the
+ parent package's name. See :pep:`366` for further details.
 
 This attribute is used instead of ``__name__`` to calculate explicit
 relative imports for main modules, as defined in :pep:`366`.
diff --git a/Lib/importlib/_bootstrap.py b/Lib/importlib/_bootstrap.py
--- a/Lib/importlib/_bootstrap.py
+++ b/Lib/importlib/_bootstrap.py
@@ -494,7 +494,7 @@
 """Set __loader__ on the returned module."""
 def set_loader_wrapper(self, *args, **kwargs):
 module = fxn(self, *args, **kwargs)
- if not hasattr(module, '__loader__'):
+ if getattr(module, '__loader__', None) is None:
 module.__loader__ = self
 return module
 _wrap(set_loader_wrapper, fxn)
@@ -875,12 +875,9 @@
 module.__cached__ = module.__file__
 else:
 module.__cached__ = module.__file__
- module.__package__ = name
 if self.is_package(name):
 module.__path__ = [_path_split(module.__file__)[0]]
- else:
- module.__package__ = module.__package__.rpartition('.')[0]
- module.__loader__ = self
+ # __package__ and __loader set by @module_for_loader.
 _call_with_frames_removed(exec, code_object, module.__dict__)
 return module
 
@@ -1551,7 +1548,7 @@
 except AttributeError:
 pass
 # Set loader if need be.
- if not hasattr(module, '__loader__'):
+ if getattr(module, '__loader__', None) is None:
 try:
 module.__loader__ = loader
 except AttributeError:
diff --git a/Lib/test/test_importlib/import_/test___loader__.py b/Lib/test/test_importlib/import_/test___loader__.py
new file mode 100644
--- /dev/null
+++ b/Lib/test/test_importlib/import_/test___loader__.py
@@ -0,0 +1,44 @@
+import imp
+import sys
+import unittest
+
+from .. import util
+from . import util as import_util
+
+
+class LoaderMock:
+
+ def find_module(self, fullname, path=None):
+ return self
+
+ def load_module(self, fullname):
+ sys.modules[fullname] = self.module
+ return self.module
+
+
+class LoaderAttributeTests(unittest.TestCase):
+
+ def test___loader___missing(self):
+ module = imp.new_module('blah')
+ try:
+ del module.__loader__
+ except AttributeError:
+ pass
+ loader = LoaderMock()
+ loader.module = module
+ with util.uncache('blah'), util.import_state(meta_path=[loader]):
+ module = import_util.import_('blah')
+ self.assertEqual(loader, module.__loader__)
+
+ def test___loader___is_None(self):
+ module = imp.new_module('blah')
+ module.__loader__ = None
+ loader = LoaderMock()
+ loader.module = module
+ with util.uncache('blah'), util.import_state(meta_path=[loader]):
+ returned_module = import_util.import_('blah')
+ self.assertEqual(loader, module.__loader__)
+
+
+if __name__ == '__main__':
+ unittest.main()
\ No newline at end of file
diff --git a/Lib/test/test_importlib/test_util.py b/Lib/test/test_importlib/test_util.py
--- a/Lib/test/test_importlib/test_util.py
+++ b/Lib/test/test_importlib/test_util.py
@@ -162,6 +162,37 @@
 self.assertEqual(wrapped.__qualname__, fxn.__qualname__)
 
 
+class SetLoaderTests(unittest.TestCase):
+
+ """Tests importlib.util.set_loader()."""
+
+ class DummyLoader:
+ @util.set_loader
+ def load_module(self, module):
+ return self.module
+
+ def test_no_attribute(self):
+ loader = self.DummyLoader()
+ loader.module = imp.new_module('blah')
+ try:
+ del loader.module.__loader__
+ except AttributeError:
+ pass
+ self.assertEqual(loader, loader.load_module('blah').__loader__)
+
+ def test_attribute_is_None(self):
+ loader = self.DummyLoader()
+ loader.module = imp.new_module('blah')
+ loader.module.__loader__ = None
+ self.assertEqual(loader, loader.load_module('blah').__loader__)
+
+ def test_not_reset(self):
+ loader = self.DummyLoader()
+ loader.module = imp.new_module('blah')
+ loader.module.__loader__ = 42
+ self.assertEqual(42, loader.load_module('blah').__loader__)
+
+
 class ResolveNameTests(unittest.TestCase):
 
 """Tests importlib.util.resolve_name()."""
@@ -195,14 +226,5 @@
 util.resolve_name('..bacon', 'spam')
 
 
-def test_main():
- from test import support
- support.run_unittest(
- ModuleForLoaderTests,
- SetPackageTests,
- ResolveNameTests
- )
-
-
 if __name__ == '__main__':
- test_main()
+ unittest.main()
diff --git a/Misc/ACKS b/Misc/ACKS
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -339,6 +339,7 @@
 Jeff Epler
 Jeff McNeil
 Tom Epperly
+Gökcen Eraslan
 Stoffel Erasmus
 Jürgen A. Erhard
 Michael Ernst
diff --git a/Misc/NEWS b/Misc/NEWS
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -10,6 +10,9 @@
 Core and Builtins
 -----------------
 
+- Issue #17117: Import and @importlib.util.set_loader now set __loader__ when
+ it has a value of None or the attribute doesn't exist.
+
 - Issue #17327: Add PyDict_SetDefault.
 
 - Issue #17032: The "global" in the "NameError: global name 'x' is not defined"
diff --git a/Python/importlib.h b/Python/importlib.h
--- a/Python/importlib.h
+++ b/Python/importlib.h
[stripped]
-- 
Repository URL: http://hg.python.org/cpython
