| """Test relative imports (PEP 328).""" |
| from .. import util |
| from . import util as import_util |
| import sys |
| import unittest |
| |
| class RelativeImports(unittest.TestCase): |
| |
| """PEP 328 introduced relative imports. This allows for imports to occur |
| from within a package without having to specify the actual package name. |
| |
| A simple example is to import another module within the same package |
| [module from module]:: |
| |
| # From pkg.mod1 with pkg.mod2 being a module. |
| from . import mod2 |
| |
| This also works for getting an attribute from a module that is specified |
| in a relative fashion [attr from module]:: |
| |
| # From pkg.mod1. |
| from .mod2 import attr |
| |
| But this is in no way restricted to working between modules; it works |
| from [package to module],:: |
| |
| # From pkg, importing pkg.module which is a module. |
| from . import module |
| |
| [module to package],:: |
| |
| # Pull attr from pkg, called from pkg.module which is a module. |
| from . import attr |
| |
| and [package to package]:: |
| |
| # From pkg.subpkg1 (both pkg.subpkg[1,2] are packages). |
| from .. import subpkg2 |
| |
| The number of dots used is in no way restricted [deep import]:: |
| |
| # Import pkg.attr from pkg.pkg1.pkg2.pkg3.pkg4.pkg5. |
| from ...... import attr |
| |
| To prevent someone from accessing code that is outside of a package, one |
| cannot reach the location containing the root package itself:: |
| |
| # From pkg.__init__ [too high from package] |
| from .. import top_level |
| |
| # From pkg.module [too high from module] |
| from .. import top_level |
| |
| Relative imports are the only type of import that allow for an empty |
| module name for an import [empty name]. |
| |
| """ |
| |
| def relative_import_test(self, create, globals_, callback): |
| """Abstract out boilerplace for setting up for an import test.""" |
| uncache_names = [] |
| for name in create: |
| if not name.endswith('.__init__'): |
| uncache_names.append(name) |
| else: |
| uncache_names.append(name[:-len('.__init__')]) |
| with util.mock_modules(*create) as importer: |
| with util.import_state(meta_path=[importer]): |
| for global_ in globals_: |
| with util.uncache(*uncache_names): |
| callback(global_) |
| |
| |
| def test_module_from_module(self): |
| # [module from module] |
| create = 'pkg.__init__', 'pkg.mod2' |
| globals_ = {'__package__': 'pkg'}, {'__name__': 'pkg.mod1'} |
| def callback(global_): |
| import_util.import_('pkg') # For __import__(). |
| module = import_util.import_('', global_, fromlist=['mod2'], level=1) |
| self.assertEqual(module.__name__, 'pkg') |
| self.assertTrue(hasattr(module, 'mod2')) |
| self.assertEqual(module.mod2.attr, 'pkg.mod2') |
| self.relative_import_test(create, globals_, callback) |
| |
| def test_attr_from_module(self): |
| # [attr from module] |
| create = 'pkg.__init__', 'pkg.mod2' |
| globals_ = {'__package__': 'pkg'}, {'__name__': 'pkg.mod1'} |
| def callback(global_): |
| import_util.import_('pkg') # For __import__(). |
| module = import_util.import_('mod2', global_, fromlist=['attr'], |
| level=1) |
| self.assertEqual(module.__name__, 'pkg.mod2') |
| self.assertEqual(module.attr, 'pkg.mod2') |
| self.relative_import_test(create, globals_, callback) |
| |
| def test_package_to_module(self): |
| # [package to module] |
| create = 'pkg.__init__', 'pkg.module' |
| globals_ = ({'__package__': 'pkg'}, |
| {'__name__': 'pkg', '__path__': ['blah']}) |
| def callback(global_): |
| import_util.import_('pkg') # For __import__(). |
| module = import_util.import_('', global_, fromlist=['module'], |
| level=1) |
| self.assertEqual(module.__name__, 'pkg') |
| self.assertTrue(hasattr(module, 'module')) |
| self.assertEqual(module.module.attr, 'pkg.module') |
| self.relative_import_test(create, globals_, callback) |
| |
| def test_module_to_package(self): |
| # [module to package] |
| create = 'pkg.__init__', 'pkg.module' |
| globals_ = {'__package__': 'pkg'}, {'__name__': 'pkg.module'} |
| def callback(global_): |
| import_util.import_('pkg') # For __import__(). |
| module = import_util.import_('', global_, fromlist=['attr'], level=1) |
| self.assertEqual(module.__name__, 'pkg') |
| self.relative_import_test(create, globals_, callback) |
| |
| def test_package_to_package(self): |
| # [package to package] |
| create = ('pkg.__init__', 'pkg.subpkg1.__init__', |
| 'pkg.subpkg2.__init__') |
| globals_ = ({'__package__': 'pkg.subpkg1'}, |
| {'__name__': 'pkg.subpkg1', '__path__': ['blah']}) |
| def callback(global_): |
| module = import_util.import_('', global_, fromlist=['subpkg2'], |
| level=2) |
| self.assertEqual(module.__name__, 'pkg') |
| self.assertTrue(hasattr(module, 'subpkg2')) |
| self.assertEqual(module.subpkg2.attr, 'pkg.subpkg2.__init__') |
| |
| def test_deep_import(self): |
| # [deep import] |
| create = ['pkg.__init__'] |
| for count in range(1,6): |
| create.append('{0}.pkg{1}.__init__'.format( |
| create[-1][:-len('.__init__')], count)) |
| globals_ = ({'__package__': 'pkg.pkg1.pkg2.pkg3.pkg4.pkg5'}, |
| {'__name__': 'pkg.pkg1.pkg2.pkg3.pkg4.pkg5', |
| '__path__': ['blah']}) |
| def callback(global_): |
| import_util.import_(globals_[0]['__package__']) |
| module = import_util.import_('', global_, fromlist=['attr'], level=6) |
| self.assertEqual(module.__name__, 'pkg') |
| self.relative_import_test(create, globals_, callback) |
| |
| def test_too_high_from_package(self): |
| # [too high from package] |
| create = ['top_level', 'pkg.__init__'] |
| globals_ = ({'__package__': 'pkg'}, |
| {'__name__': 'pkg', '__path__': ['blah']}) |
| def callback(global_): |
| import_util.import_('pkg') |
| with self.assertRaises(ValueError): |
| import_util.import_('', global_, fromlist=['top_level'], |
| level=2) |
| self.relative_import_test(create, globals_, callback) |
| |
| def test_too_high_from_module(self): |
| # [too high from module] |
| create = ['top_level', 'pkg.__init__', 'pkg.module'] |
| globals_ = {'__package__': 'pkg'}, {'__name__': 'pkg.module'} |
| def callback(global_): |
| import_util.import_('pkg') |
| with self.assertRaises(ValueError): |
| import_util.import_('', global_, fromlist=['top_level'], |
| level=2) |
| self.relative_import_test(create, globals_, callback) |
| |
| def test_empty_name_w_level_0(self): |
| # [empty name] |
| with self.assertRaises(ValueError): |
| import_util.import_('') |
| |
| def test_import_from_different_package(self): |
| # Test importing from a different package than the caller. |
| # in pkg.subpkg1.mod |
| # from ..subpkg2 import mod |
| create = ['__runpy_pkg__.__init__', |
| '__runpy_pkg__.__runpy_pkg__.__init__', |
| '__runpy_pkg__.uncle.__init__', |
| '__runpy_pkg__.uncle.cousin.__init__', |
| '__runpy_pkg__.uncle.cousin.nephew'] |
| globals_ = {'__package__': '__runpy_pkg__.__runpy_pkg__'} |
| def callback(global_): |
| import_util.import_('__runpy_pkg__.__runpy_pkg__') |
| module = import_util.import_('uncle.cousin', globals_, {}, |
| fromlist=['nephew'], |
| level=2) |
| self.assertEqual(module.__name__, '__runpy_pkg__.uncle.cousin') |
| self.relative_import_test(create, globals_, callback) |
| |
| |
| |
| def test_main(): |
| from test.support import run_unittest |
| run_unittest(RelativeImports) |
| |
| if __name__ == '__main__': |
| test_main() |