Add importlib.util.resolve_name().
diff --git a/Lib/importlib/test/test_util.py b/Lib/importlib/test/test_util.py
index 7963e4f..e477f17 100644
--- a/Lib/importlib/test/test_util.py
+++ b/Lib/importlib/test/test_util.py
@@ -161,9 +161,47 @@
self.assertEqual(wrapped.__name__, fxn.__name__)
self.assertEqual(wrapped.__qualname__, fxn.__qualname__)
+
+class ResolveNameTests(unittest.TestCase):
+
+ """Tests importlib.util.resolve_name()."""
+
+ def test_absolute(self):
+ # bacon
+ self.assertEqual('bacon', util.resolve_name('bacon', None))
+
+ def test_aboslute_within_package(self):
+ # bacon in spam
+ self.assertEqual('bacon', util.resolve_name('bacon', 'spam'))
+
+ def test_no_package(self):
+ # .bacon in ''
+ with self.assertRaises(ValueError):
+ util.resolve_name('.bacon', '')
+
+ def test_in_package(self):
+ # .bacon in spam
+ self.assertEqual('spam.eggs.bacon',
+ util.resolve_name('.bacon', 'spam.eggs'))
+
+ def test_other_package(self):
+ # ..bacon in spam.bacon
+ self.assertEqual('spam.bacon',
+ util.resolve_name('..bacon', 'spam.eggs'))
+
+ def test_escape(self):
+ # ..bacon in spam
+ with self.assertRaises(ValueError):
+ util.resolve_name('..bacon', 'spam')
+
+
def test_main():
from test import support
- support.run_unittest(ModuleForLoaderTests, SetPackageTests)
+ support.run_unittest(
+ ModuleForLoaderTests,
+ SetPackageTests,
+ ResolveNameTests
+ )
if __name__ == '__main__':
diff --git a/Lib/importlib/util.py b/Lib/importlib/util.py
index 7b44fa1..1316437 100644
--- a/Lib/importlib/util.py
+++ b/Lib/importlib/util.py
@@ -3,3 +3,19 @@
from ._bootstrap import module_for_loader
from ._bootstrap import set_loader
from ._bootstrap import set_package
+from ._bootstrap import _resolve_name
+
+
+def resolve_name(name, package):
+ """Resolve a relative module name to an absolute one."""
+ if not name.startswith('.'):
+ return name
+ elif not package:
+ raise ValueError('{!r} is not a relative name '
+ '(no leading dot)'.format(name))
+ level = 0
+ for character in name:
+ if character != '.':
+ break
+ level += 1
+ return _resolve_name(name[level:], package, level)