[Python-checkins] cpython: Add importlib.util.resolve_name().
brett.cannon
python-checkins at python.org
Sun May 13 19:45:14 CEST 2012
http://hg.python.org/cpython/rev/767503ba72e7
changeset: 76905:767503ba72e7
user: Brett Cannon <brett at python.org>
date: Sun May 13 13:45:09 2012 -0400
summary:
Add importlib.util.resolve_name().
files:
Doc/library/importlib.rst | 16 ++++++++
Lib/importlib/test/test_util.py | 40 ++++++++++++++++++++-
Lib/importlib/util.py | 16 ++++++++
Misc/NEWS | 2 +
4 files changed, 73 insertions(+), 1 deletions(-)
diff --git a/Doc/library/importlib.rst b/Doc/library/importlib.rst
--- a/Doc/library/importlib.rst
+++ b/Doc/library/importlib.rst
@@ -737,6 +737,22 @@
This module contains the various objects that help in the construction of
an :term:`importer`.
+.. function:: resolve_name(name, package)
+
+ Resolve a relative module name to an absolute one.
+
+ If **name** has no leading dots, then **name** is simply returned. This
+ allows for usage such as
+ ``importlib.util.resolve_name('sys', __package__)`` without doing a
+ check to see if the **package** argument is needed.
+
+ :exc:`ValueError` is raised if **name** is a relative module name but
+ package is a false value (e.g. ``None`` or the empty string).
+ :exc:`ValueError` is also raised a relative name would escape its containing
+ package (e.g. requesting ``..bacon`` from within the ``spam`` package).
+
+ .. versionadded:: 3.3
+
.. decorator:: module_for_loader
A :term:`decorator` for a :term:`loader` method,
diff --git a/Lib/importlib/test/test_util.py b/Lib/importlib/test/test_util.py
--- 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
--- 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)
diff --git a/Misc/NEWS b/Misc/NEWS
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -23,6 +23,8 @@
Library
-------
+- Add importlib.util.resolve_name().
+
- Issue #14366: Support lzma compression in zip files.
Patch by Serhiy Storchaka.
--
Repository URL: http://hg.python.org/cpython
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