"""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
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, 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.assertEquals(module.__name__, 'pkg')
def test_using___name__(self):
# [__name__]
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={'__name__': 'pkg.fake',
'__path__': []},
fromlist=['attr'], level=2)
self.assertEquals(module.__name__, 'pkg')
def test_bad__package__(self):
globals = {'__package__': '<not real>'}
self.assertRaises(SystemError, import_util.import_,'', globals, {},
['relimport'], 1)
def test_bunk__package__(self):
globals = {'__package__': 42}
self.assertRaises(ValueError, import_util.import_, '', globals, {},
['relimport'], 1)
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()
|