| """PEP 366 ("Main module explicit relative imports") specifies the |
| semantics for the __package__ attribute on modules. This attribute is |
| used, when available, to detect which package a module belongs to (instead |
| of using the typical __path__/__name__ test). |
| |
| """ |
| import unittest |
| from .. import util |
| from . import util as import_util |
| |
| |
| class Using__package__(unittest.TestCase): |
| |
| """Use of __package__ supercedes the use of __name__/__path__ to calculate |
| what package a module belongs to. The basic algorithm is [__package__]:: |
| |
| def resolve_name(name, package, level): |
| level -= 1 |
| base = package.rsplit('.', level)[0] |
| return '{0}.{1}'.format(base, name) |
| |
| But since there is no guarantee that __package__ has been set (or not been |
| set to None [None]), there has to be a way to calculate the attribute's value |
| [__name__]:: |
| |
| def calc_package(caller_name, has___path__): |
| if has__path__: |
| return caller_name |
| else: |
| return caller_name.rsplit('.', 1)[0] |
| |
| Then the normal algorithm for relative name imports can proceed as if |
| __package__ had been set. |
| |
| """ |
| |
| def test_using___package__(self): |
| # [__package__] |
| with util.mock_modules('pkg.__init__', 'pkg.fake') as importer: |
| with util.import_state(meta_path=[importer]): |
| import_util.import_('pkg.fake') |
| module = import_util.import_('', |
| globals={'__package__': 'pkg.fake'}, |
| fromlist=['attr'], level=2) |
| self.assertEqual(module.__name__, 'pkg') |
| |
| def test_using___name__(self, package_as_None=False): |
| # [__name__] |
| globals_ = {'__name__': 'pkg.fake', '__path__': []} |
| if package_as_None: |
| globals_['__package__'] = None |
| with util.mock_modules('pkg.__init__', 'pkg.fake') as importer: |
| with util.import_state(meta_path=[importer]): |
| import_util.import_('pkg.fake') |
| module = import_util.import_('', globals= globals_, |
| fromlist=['attr'], level=2) |
| self.assertEqual(module.__name__, 'pkg') |
| |
| def test_None_as___package__(self): |
| # [None] |
| self.test_using___name__(package_as_None=True) |
| |
| def test_bad__package__(self): |
| globals = {'__package__': '<not real>'} |
| with self.assertRaises(SystemError): |
| import_util.import_('', globals, {}, ['relimport'], 1) |
| |
| def test_bunk__package__(self): |
| globals = {'__package__': 42} |
| with self.assertRaises(ValueError): |
| import_util.import_('', globals, {}, ['relimport'], 1) |
| |
| |
| @import_util.importlib_only |
| class Setting__package__(unittest.TestCase): |
| |
| """Because __package__ is a new feature, it is not always set by a loader. |
| Import will set it as needed to help with the transition to relying on |
| __package__. |
| |
| For a top-level module, __package__ is set to None [top-level]. For a |
| package __name__ is used for __package__ [package]. For submodules the |
| value is __name__.rsplit('.', 1)[0] [submodule]. |
| |
| """ |
| |
| # [top-level] |
| def test_top_level(self): |
| with util.mock_modules('top_level') as mock: |
| with util.import_state(meta_path=[mock]): |
| del mock['top_level'].__package__ |
| module = import_util.import_('top_level') |
| self.assertEqual(module.__package__, '') |
| |
| # [package] |
| def test_package(self): |
| with util.mock_modules('pkg.__init__') as mock: |
| with util.import_state(meta_path=[mock]): |
| del mock['pkg'].__package__ |
| module = import_util.import_('pkg') |
| self.assertEqual(module.__package__, 'pkg') |
| |
| # [submodule] |
| def test_submodule(self): |
| with util.mock_modules('pkg.__init__', 'pkg.mod') as mock: |
| with util.import_state(meta_path=[mock]): |
| del mock['pkg.mod'].__package__ |
| pkg = import_util.import_('pkg.mod') |
| module = getattr(pkg, 'mod') |
| self.assertEqual(module.__package__, 'pkg') |
| |
| |
| def test_main(): |
| from test.support import run_unittest |
| run_unittest(Using__package__, Setting__package__) |
| |
| |
| if __name__ == '__main__': |
| test_main() |