Fixed #13464 -- Reworked module_has_submodule to break the requirement for loader and finder to be the same class. Thanks to Alex Gaynor for the report and patch, and Brett Cannon for suggesting the approach.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@13082 bcc190cf-cafb-0310-a4f2-bffc1f526a37
This commit is contained in:
Russell Keith-Magee 2010-05-04 06:14:47 +00:00
parent 7fc25715d6
commit 4ca7c4e34d
7 changed files with 199 additions and 21 deletions

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@ -1,26 +1,60 @@
import os
import imp import imp
import os
import sys
def module_has_submodule(mod, submod_name):
# If the module was loaded from an egg, __loader__ will be set and
# its find_module must be used to search for submodules.
loader = getattr(mod, '__loader__', None)
if loader:
mod_path = "%s.%s" % (mod.__name__.rsplit('.',1)[-1], submod_name)
x = loader.find_module(mod_path)
if x is None:
# zipimport.zipimporter.find_module is documented to take
# dotted paths but in fact through Python 2.7 is observed
# to require os.sep in place of dots...so try using os.sep
# if the dotted path version failed to find the requested
# submodule.
x = loader.find_module(mod_path.replace('.', os.sep))
return x is not None
try: def module_has_submodule(package, module_name):
imp.find_module(submod_name, mod.__path__) """See if 'module' is in 'package'."""
name = ".".join([package.__name__, module_name])
if name in sys.modules:
return True return True
except ImportError: for finder in sys.meta_path:
if finder.find_module(name):
return True
for entry in package.__path__: # No __path__, then not a package.
try:
# Try the cached finder.
finder = sys.path_importer_cache[entry]
if finder is None:
# Implicit import machinery should be used.
try:
file_, _, _ = imp.find_module(module_name, [entry])
if file_:
file_.close()
return True
except ImportError:
continue
# Else see if the finder knows of a loader.
elif finder.find_module(name):
return True
else:
continue
except KeyError:
# No cached finder, so try and make one.
for hook in sys.path_hooks:
try:
finder = hook(entry)
# XXX Could cache in sys.path_importer_cache
if finder.find_module(name):
return True
else:
# Once a finder is found, stop the search.
break
except ImportError:
# Continue the search for a finder.
continue
else:
# No finder found.
# Try the implicit import machinery if searching a directory.
if os.path.isdir(entry):
try:
file_, _, _ = imp.find_module(module_name, [entry])
if file_:
file_.close()
return True
except ImportError:
pass
# XXX Could insert None or NullImporter
else:
# Exhausted the search, so the module cannot be found.
return False return False

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@ -0,0 +1,139 @@
import os
import sys
from unittest import TestCase
from zipimport import zipimporter
from django.utils.importlib import import_module
from django.utils.module_loading import module_has_submodule
class DefaultLoader(TestCase):
def test_loader(self):
"Normal module existence can be tested"
test_module = import_module('regressiontests.utils.test_module')
# An importable child
self.assertTrue(module_has_submodule(test_module, 'good_module'))
mod = import_module('regressiontests.utils.test_module.good_module')
self.assertEqual(mod.content, 'Good Module')
# A child that exists, but will generate an import error if loaded
self.assertTrue(module_has_submodule(test_module, 'bad_module'))
self.assertRaises(ImportError, import_module, 'regressiontests.utils.test_module.bad_module')
# A child that doesn't exist
self.assertFalse(module_has_submodule(test_module, 'no_such_module'))
self.assertRaises(ImportError, import_module, 'regressiontests.utils.test_module.no_such_module')
class EggLoader(TestCase):
def setUp(self):
self.old_path = sys.path
self.egg_dir = '%s/eggs' % os.path.dirname(__file__)
def tearDown(self):
sys.path = self.old_path
def test_shallow_loader(self):
"Module existence can be tested inside eggs"
egg_name = '%s/test_egg.egg' % self.egg_dir
sys.path.append(egg_name)
egg_module = import_module('egg_module')
# An importable child
self.assertTrue(module_has_submodule(egg_module, 'good_module'))
mod = import_module('egg_module.good_module')
self.assertEqual(mod.content, 'Good Module')
# A child that exists, but will generate an import error if loaded
self.assertTrue(module_has_submodule(egg_module, 'bad_module'))
self.assertRaises(ImportError, import_module, 'egg_module.bad_module')
# A child that doesn't exist
self.assertFalse(module_has_submodule(egg_module, 'no_such_module'))
self.assertRaises(ImportError, import_module, 'egg_module.no_such_module')
def test_deep_loader(self):
"Modules deep inside an egg can still be tested for existence"
egg_name = '%s/test_egg.egg' % self.egg_dir
sys.path.append(egg_name)
egg_module = import_module('egg_module.sub1.sub2')
# An importable child
self.assertTrue(module_has_submodule(egg_module, 'good_module'))
mod = import_module('egg_module.sub1.sub2.good_module')
self.assertEqual(mod.content, 'Deep Good Module')
# A child that exists, but will generate an import error if loaded
self.assertTrue(module_has_submodule(egg_module, 'bad_module'))
self.assertRaises(ImportError, import_module, 'egg_module.sub1.sub2.bad_module')
# A child that doesn't exist
self.assertFalse(module_has_submodule(egg_module, 'no_such_module'))
self.assertRaises(ImportError, import_module, 'egg_module.sub1.sub2.no_such_module')
class TestFinder(object):
def __init__(self, *args, **kwargs):
self.importer = zipimporter(*args, **kwargs)
def find_module(self, path):
importer = self.importer.find_module(path)
if importer is None:
return
return TestLoader(importer)
class TestLoader(object):
def __init__(self, importer):
self.importer = importer
def load_module(self, name):
mod = self.importer.load_module(name)
mod.__loader__ = self
return mod
class CustomLoader(TestCase):
def setUp(self):
self.egg_dir = '%s/eggs' % os.path.dirname(__file__)
self.old_path = sys.path
sys.path_hooks.insert(0, TestFinder)
sys.path_importer_cache.clear()
def tearDown(self):
sys.path = self.old_path
sys.path_hooks.pop(0)
def test_shallow_loader(self):
"Module existence can be tested with a custom loader"
egg_name = '%s/test_egg.egg' % self.egg_dir
sys.path.append(egg_name)
egg_module = import_module('egg_module')
# An importable child
self.assertTrue(module_has_submodule(egg_module, 'good_module'))
mod = import_module('egg_module.good_module')
self.assertEqual(mod.content, 'Good Module')
# A child that exists, but will generate an import error if loaded
self.assertTrue(module_has_submodule(egg_module, 'bad_module'))
self.assertRaises(ImportError, import_module, 'egg_module.bad_module')
# A child that doesn't exist
self.assertFalse(module_has_submodule(egg_module, 'no_such_module'))
self.assertRaises(ImportError, import_module, 'egg_module.no_such_module')
def test_deep_loader(self):
"Modules existence can be tested deep inside a custom loader"
egg_name = '%s/test_egg.egg' % self.egg_dir
sys.path.append(egg_name)
egg_module = import_module('egg_module.sub1.sub2')
# An importable child
self.assertTrue(module_has_submodule(egg_module, 'good_module'))
mod = import_module('egg_module.sub1.sub2.good_module')
self.assertEqual(mod.content, 'Deep Good Module')
# A child that exists, but will generate an import error if loaded
self.assertTrue(module_has_submodule(egg_module, 'bad_module'))
self.assertRaises(ImportError, import_module, 'egg_module.sub1.sub2.bad_module')
# A child that doesn't exist
self.assertFalse(module_has_submodule(egg_module, 'no_such_module'))
self.assertRaises(ImportError, import_module, 'egg_module.sub1.sub2.no_such_module')

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import a_package_name_that_does_not_exist
content = 'Bad Module'

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content = 'Good Module'

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@ -34,6 +34,7 @@ __test__ = {
from dateformat import * from dateformat import *
from feedgenerator import * from feedgenerator import *
from module_loading import *
from termcolors import * from termcolors import *
class TestUtilsHtml(TestCase): class TestUtilsHtml(TestCase):