Python code coverage for Lib/test/test_importlib/import_/test_relative_imports.py

#	count	content
1	n/a	"""Test relative imports (PEP 328)."""
2	n/a	from .. import util
3	n/a	import unittest
4	n/a	import warnings
5	n/a
6	n/a
7	n/a	class RelativeImports:
8	n/a
9	n/a	"""PEP 328 introduced relative imports. This allows for imports to occur
10	n/a	from within a package without having to specify the actual package name.
11	n/a
12	n/a	A simple example is to import another module within the same package
13	n/a	[module from module]::
14	n/a
15	n/a	# From pkg.mod1 with pkg.mod2 being a module.
16	n/a	from . import mod2
17	n/a
18	n/a	This also works for getting an attribute from a module that is specified
19	n/a	in a relative fashion [attr from module]::
20	n/a
21	n/a	# From pkg.mod1.
22	n/a	from .mod2 import attr
23	n/a
24	n/a	But this is in no way restricted to working between modules; it works
25	n/a	from [package to module],::
26	n/a
27	n/a	# From pkg, importing pkg.module which is a module.
28	n/a	from . import module
29	n/a
30	n/a	[module to package],::
31	n/a
32	n/a	# Pull attr from pkg, called from pkg.module which is a module.
33	n/a	from . import attr
34	n/a
35	n/a	and [package to package]::
36	n/a
37	n/a	# From pkg.subpkg1 (both pkg.subpkg[1,2] are packages).
38	n/a	from .. import subpkg2
39	n/a
40	n/a	The number of dots used is in no way restricted [deep import]::
41	n/a
42	n/a	# Import pkg.attr from pkg.pkg1.pkg2.pkg3.pkg4.pkg5.
43	n/a	from ...... import attr
44	n/a
45	n/a	To prevent someone from accessing code that is outside of a package, one
46	n/a	cannot reach the location containing the root package itself::
47	n/a
48	n/a	# From pkg.__init__ [too high from package]
49	n/a	from .. import top_level
50	n/a
51	n/a	# From pkg.module [too high from module]
52	n/a	from .. import top_level
53	n/a
54	n/a	Relative imports are the only type of import that allow for an empty
55	n/a	module name for an import [empty name].
56	n/a
57	n/a	"""
58	n/a
59	n/a	def relative_import_test(self, create, globals_, callback):
60	n/a	"""Abstract out boilerplace for setting up for an import test."""
61	n/a	uncache_names = []
62	n/a	for name in create:
63	n/a	if not name.endswith('.__init__'):
64	n/a	uncache_names.append(name)
65	n/a	else:
66	n/a	uncache_names.append(name[:-len('.__init__')])
67	n/a	with util.mock_spec(*create) as importer:
68	n/a	with util.import_state(meta_path=[importer]):
69	n/a	with warnings.catch_warnings():
70	n/a	warnings.simplefilter("ignore")
71	n/a	for global_ in globals_:
72	n/a	with util.uncache(*uncache_names):
73	n/a	callback(global_)
74	n/a
75	n/a
76	n/a	def test_module_from_module(self):
77	n/a	# [module from module]
78	n/a	create = 'pkg.__init__', 'pkg.mod2'
79	n/a	globals_ = {'__package__': 'pkg'}, {'__name__': 'pkg.mod1'}
80	n/a	def callback(global_):
81	n/a	self.__import__('pkg') # For __import__().
82	n/a	module = self.__import__('', global_, fromlist=['mod2'], level=1)
83	n/a	self.assertEqual(module.__name__, 'pkg')
84	n/a	self.assertTrue(hasattr(module, 'mod2'))
85	n/a	self.assertEqual(module.mod2.attr, 'pkg.mod2')
86	n/a	self.relative_import_test(create, globals_, callback)
87	n/a
88	n/a	def test_attr_from_module(self):
89	n/a	# [attr from module]
90	n/a	create = 'pkg.__init__', 'pkg.mod2'
91	n/a	globals_ = {'__package__': 'pkg'}, {'__name__': 'pkg.mod1'}
92	n/a	def callback(global_):
93	n/a	self.__import__('pkg') # For __import__().
94	n/a	module = self.__import__('mod2', global_, fromlist=['attr'],
95	n/a	level=1)
96	n/a	self.assertEqual(module.__name__, 'pkg.mod2')
97	n/a	self.assertEqual(module.attr, 'pkg.mod2')
98	n/a	self.relative_import_test(create, globals_, callback)
99	n/a
100	n/a	def test_package_to_module(self):
101	n/a	# [package to module]
102	n/a	create = 'pkg.__init__', 'pkg.module'
103	n/a	globals_ = ({'__package__': 'pkg'},
104	n/a	{'__name__': 'pkg', '__path__': ['blah']})
105	n/a	def callback(global_):
106	n/a	self.__import__('pkg') # For __import__().
107	n/a	module = self.__import__('', global_, fromlist=['module'],
108	n/a	level=1)
109	n/a	self.assertEqual(module.__name__, 'pkg')
110	n/a	self.assertTrue(hasattr(module, 'module'))
111	n/a	self.assertEqual(module.module.attr, 'pkg.module')
112	n/a	self.relative_import_test(create, globals_, callback)
113	n/a
114	n/a	def test_module_to_package(self):
115	n/a	# [module to package]
116	n/a	create = 'pkg.__init__', 'pkg.module'
117	n/a	globals_ = {'__package__': 'pkg'}, {'__name__': 'pkg.module'}
118	n/a	def callback(global_):
119	n/a	self.__import__('pkg') # For __import__().
120	n/a	module = self.__import__('', global_, fromlist=['attr'], level=1)
121	n/a	self.assertEqual(module.__name__, 'pkg')
122	n/a	self.relative_import_test(create, globals_, callback)
123	n/a
124	n/a	def test_package_to_package(self):
125	n/a	# [package to package]
126	n/a	create = ('pkg.__init__', 'pkg.subpkg1.__init__',
127	n/a	'pkg.subpkg2.__init__')
128	n/a	globals_ = ({'__package__': 'pkg.subpkg1'},
129	n/a	{'__name__': 'pkg.subpkg1', '__path__': ['blah']})
130	n/a	def callback(global_):
131	n/a	module = self.__import__('', global_, fromlist=['subpkg2'],
132	n/a	level=2)
133	n/a	self.assertEqual(module.__name__, 'pkg')
134	n/a	self.assertTrue(hasattr(module, 'subpkg2'))
135	n/a	self.assertEqual(module.subpkg2.attr, 'pkg.subpkg2.__init__')
136	n/a
137	n/a	def test_deep_import(self):
138	n/a	# [deep import]
139	n/a	create = ['pkg.__init__']
140	n/a	for count in range(1,6):
141	n/a	create.append('{0}.pkg{1}.__init__'.format(
142	n/a	create[-1][:-len('.__init__')], count))
143	n/a	globals_ = ({'__package__': 'pkg.pkg1.pkg2.pkg3.pkg4.pkg5'},
144	n/a	{'__name__': 'pkg.pkg1.pkg2.pkg3.pkg4.pkg5',
145	n/a	'__path__': ['blah']})
146	n/a	def callback(global_):
147	n/a	self.__import__(globals_[0]['__package__'])
148	n/a	module = self.__import__('', global_, fromlist=['attr'], level=6)
149	n/a	self.assertEqual(module.__name__, 'pkg')
150	n/a	self.relative_import_test(create, globals_, callback)
151	n/a
152	n/a	def test_too_high_from_package(self):
153	n/a	# [too high from package]
154	n/a	create = ['top_level', 'pkg.__init__']
155	n/a	globals_ = ({'__package__': 'pkg'},
156	n/a	{'__name__': 'pkg', '__path__': ['blah']})
157	n/a	def callback(global_):
158	n/a	self.__import__('pkg')
159	n/a	with self.assertRaises(ValueError):
160	n/a	self.__import__('', global_, fromlist=['top_level'],
161	n/a	level=2)
162	n/a	self.relative_import_test(create, globals_, callback)
163	n/a
164	n/a	def test_too_high_from_module(self):
165	n/a	# [too high from module]
166	n/a	create = ['top_level', 'pkg.__init__', 'pkg.module']
167	n/a	globals_ = {'__package__': 'pkg'}, {'__name__': 'pkg.module'}
168	n/a	def callback(global_):
169	n/a	self.__import__('pkg')
170	n/a	with self.assertRaises(ValueError):
171	n/a	self.__import__('', global_, fromlist=['top_level'],
172	n/a	level=2)
173	n/a	self.relative_import_test(create, globals_, callback)
174	n/a
175	n/a	def test_empty_name_w_level_0(self):
176	n/a	# [empty name]
177	n/a	with self.assertRaises(ValueError):
178	n/a	self.__import__('')
179	n/a
180	n/a	def test_import_from_different_package(self):
181	n/a	# Test importing from a different package than the caller.
182	n/a	# in pkg.subpkg1.mod
183	n/a	# from ..subpkg2 import mod
184	n/a	create = ['__runpy_pkg__.__init__',
185	n/a	'__runpy_pkg__.__runpy_pkg__.__init__',
186	n/a	'__runpy_pkg__.uncle.__init__',
187	n/a	'__runpy_pkg__.uncle.cousin.__init__',
188	n/a	'__runpy_pkg__.uncle.cousin.nephew']
189	n/a	globals_ = {'__package__': '__runpy_pkg__.__runpy_pkg__'}
190	n/a	def callback(global_):
191	n/a	self.__import__('__runpy_pkg__.__runpy_pkg__')
192	n/a	module = self.__import__('uncle.cousin', globals_, {},
193	n/a	fromlist=['nephew'],
194	n/a	level=2)
195	n/a	self.assertEqual(module.__name__, '__runpy_pkg__.uncle.cousin')
196	n/a	self.relative_import_test(create, globals_, callback)
197	n/a
198	n/a	def test_import_relative_import_no_fromlist(self):
199	n/a	# Import a relative module w/ no fromlist.
200	n/a	create = ['crash.__init__', 'crash.mod']
201	n/a	globals_ = [{'__package__': 'crash', '__name__': 'crash'}]
202	n/a	def callback(global_):
203	n/a	self.__import__('crash')
204	n/a	mod = self.__import__('mod', global_, {}, [], 1)
205	n/a	self.assertEqual(mod.__name__, 'crash.mod')
206	n/a	self.relative_import_test(create, globals_, callback)
207	n/a
208	n/a	def test_relative_import_no_globals(self):
209	n/a	# No globals for a relative import is an error.
210	n/a	with warnings.catch_warnings():
211	n/a	warnings.simplefilter("ignore")
212	n/a	with self.assertRaises(KeyError):
213	n/a	self.__import__('sys', level=1)
214	n/a
215	n/a	def test_relative_import_no_package(self):
216	n/a	with self.assertRaises(ImportError):
217	n/a	self.__import__('a', {'__package__': '', '__spec__': None},
218	n/a	level=1)
219	n/a
220	n/a	def test_relative_import_no_package_exists_absolute(self):
221	n/a	with self.assertRaises(ImportError):
222	n/a	self.__import__('sys', {'__package__': '', '__spec__': None},
223	n/a	level=1)
224	n/a
225	n/a
226	n/a	(Frozen_RelativeImports,
227	n/a	Source_RelativeImports
228	n/a	) = util.test_both(RelativeImports, __import__=util.__import__)
229	n/a
230	n/a
231	n/a	if __name__ == '__main__':
232	n/a	unittest.main()