Lib/test/test_import.py

   1 import unittest
   2 import os
   3 import random
   4 import shutil
   5 import sys
   6 import py_compile
   7 import warnings
   8 import imp
   9 import marshal
  10 from test.support import unlink, TESTFN, unload, run_unittest
  11
  12
  13 def remove_files(name):
  14     for f in (name + ".py",
  15               name + ".pyc",
  16               name + ".pyo",
  17               name + ".pyw",
  18               name + "$py.class"):
  19         if os.path.exists(f):
  20             os.remove(f)
  21
  22
  23 class ImportTest(unittest.TestCase):
  24
  25     def testCaseSensitivity(self):
  26         # Brief digression to test that import is case-sensitive:  if we got this
  27         # far, we know for sure that "random" exists.
  28         try:
  29             import RAnDoM
  30         except ImportError:
  31             pass
  32         else:
  33             self.fail("import of RAnDoM should have failed (case mismatch)")
  34
  35     def testDoubleConst(self):
  36         # Another brief digression to test the accuracy of manifest float constants.
  37         from test import double_const  # don't blink -- that *was* the test
  38
  39     def testImport(self):
  40         def test_with_extension(ext):
  41             # ext normally ".py"; perhaps ".pyw"
  42             source = TESTFN + ext
  43             pyo = TESTFN + ".pyo"
  44             if sys.platform.startswith('java'):
  45                 pyc = TESTFN + "$py.class"
  46             else:
  47                 pyc = TESTFN + ".pyc"
  48
  49             with open(source, "w") as f:
  50                 print("# This tests Python's ability to import a", ext, "file.", file=f)
  51                 a = random.randrange(1000)
  52                 b = random.randrange(1000)
  53                 print("a =", a, file=f)
  54                 print("b =", b, file=f)
  55
  56             if TESTFN in sys.modules:
  57                 del sys.modules[TESTFN]
  58             try:
  59                 try:
  60                     mod = __import__(TESTFN)
  61                 except ImportError as err:
  62                     self.fail("import from %s failed: %s" % (ext, err))
  63
  64                 self.assertEquals(mod.a, a,
  65                     "module loaded (%s) but contents invalid" % mod)
  66                 self.assertEquals(mod.b, b,
  67                     "module loaded (%s) but contents invalid" % mod)
  68             finally:
  69                 unlink(source)
  70                 unlink(pyc)
  71                 unlink(pyo)
  72                 del sys.modules[TESTFN]
  73
  74         sys.path.insert(0, os.curdir)
  75         try:
  76             test_with_extension(".py")
  77             if sys.platform.startswith("win"):
  78                 for ext in ".PY", ".Py", ".pY", ".pyw", ".PYW", ".pYw":
  79                     test_with_extension(ext)
  80         finally:
  81             del sys.path[0]
  82
  83     def testImpModule(self):
  84         # Verify that the imp module can correctly load and find .py files
  85         import imp
  86         x = imp.find_module("os")
  87         os = imp.load_module("os", *x)
  88
  89     def test_module_with_large_stack(self, module='longlist'):
  90         # create module w/list of 65000 elements to test bug #561858
  91         filename = module + '.py'
  92
  93         # create a file with a list of 65000 elements
  94         f = open(filename, 'w+')
  95         f.write('d = [\n')
  96         for i in range(65000):
  97             f.write('"",\n')
  98         f.write(']')
  99         f.close()
 100
 101         # compile & remove .py file, we only need .pyc (or .pyo)
 102         f = open(filename, 'r')
 103         py_compile.compile(filename)
 104         f.close()
 105         os.unlink(filename)
 106
 107         # need to be able to load from current dir
 108         sys.path.append('')
 109
 110         # this used to crash
 111         exec('import ' + module)
 112
 113         # cleanup
 114         del sys.path[-1]
 115         for ext in '.pyc', '.pyo':
 116             fname = module + ext
 117             if os.path.exists(fname):
 118                 os.unlink(fname)
 119
 120     def test_failing_import_sticks(self):
 121         source = TESTFN + ".py"
 122         f = open(source, "w")
 123         print("a = 1/0", file=f)
 124         f.close()
 125
 126         # New in 2.4, we shouldn't be able to import that no matter how often
 127         # we try.
 128         sys.path.insert(0, os.curdir)
 129         if TESTFN in sys.modules:
 130             del sys.modules[TESTFN]
 131         try:
 132             for i in 1, 2, 3:
 133                 try:
 134                     mod = __import__(TESTFN)
 135                 except ZeroDivisionError:
 136                     if TESTFN in sys.modules:
 137                         self.fail("damaged module in sys.modules on %i. try" % i)
 138                 else:
 139                     self.fail("was able to import a damaged module on %i. try" % i)
 140         finally:
 141             sys.path.pop(0)
 142             remove_files(TESTFN)
 143
 144     def test_import_name_binding(self):
 145         # import x.y.z binds x in the current namespace
 146         import test as x
 147         import test.support
 148         self.assert_(x is test, x.__name__)
 149         self.assert_(hasattr(test.support, "__file__"))
 150
 151         # import x.y.z as w binds z as w
 152         import test.support as y
 153         self.assert_(y is test.support, y.__name__)
 154
 155     def test_import_initless_directory_warning(self):
 156         with warnings.catch_warnings():
 157             # Just a random non-package directory we always expect to be
 158             # somewhere in sys.path...
 159             warnings.simplefilter('error', ImportWarning)
 160             self.assertRaises(ImportWarning, __import__, "site-packages")
 161
 162     def test_failing_reload(self):
 163         # A failing reload should leave the module object in sys.modules.
 164         source = TESTFN + ".py"
 165         with open(source, "w") as f:
 166             f.write("a = 1\nb=2\n")
 167
 168         sys.path.insert(0, os.curdir)
 169         try:
 170             mod = __import__(TESTFN)
 171             self.assert_(TESTFN in sys.modules, "expected module in sys.modules")
 172             self.assertEquals(mod.a, 1, "module has wrong attribute values")
 173             self.assertEquals(mod.b, 2, "module has wrong attribute values")
 174
 175             # On WinXP, just replacing the .py file wasn't enough to
 176             # convince reload() to reparse it.  Maybe the timestamp didn't
 177             # move enough.  We force it to get reparsed by removing the
 178             # compiled file too.
 179             remove_files(TESTFN)
 180
 181             # Now damage the module.
 182             with open(source, "w") as f:
 183                 f.write("a = 10\nb=20//0\n")
 184
 185             self.assertRaises(ZeroDivisionError, imp.reload, mod)
 186             # But we still expect the module to be in sys.modules.
 187             mod = sys.modules.get(TESTFN)
 188             self.failIf(mod is None, "expected module to still be in sys.modules")
 189
 190             # We should have replaced a w/ 10, but the old b value should
 191             # stick.
 192             self.assertEquals(mod.a, 10, "module has wrong attribute values")
 193             self.assertEquals(mod.b, 2, "module has wrong attribute values")
 194
 195         finally:
 196             sys.path.pop(0)
 197             remove_files(TESTFN)
 198             if TESTFN in sys.modules:
 199                 del sys.modules[TESTFN]
 200
 201     def test_file_to_source(self):
 202         # check if __file__ points to the source file where available
 203         source = TESTFN + ".py"
 204         with open(source, "w") as f:
 205             f.write("test = None\n")
 206
 207         sys.path.insert(0, os.curdir)
 208         try:
 209             mod = __import__(TESTFN)
 210             self.failUnless(mod.__file__.endswith('.py'))
 211             os.remove(source)
 212             del sys.modules[TESTFN]
 213             mod = __import__(TESTFN)
 214             ext = mod.__file__[-4:]
 215             self.failUnless(ext in ('.pyc', '.pyo'), ext)
 216         finally:
 217             sys.path.pop(0)
 218             remove_files(TESTFN)
 219             if TESTFN in sys.modules:
 220                 del sys.modules[TESTFN]
 221
 222
 223     def test_importbyfilename(self):
 224         path = os.path.abspath(TESTFN)
 225         try:
 226             __import__(path)
 227         except ImportError as err:
 228             self.assertEqual("Import by filename is not supported.",
 229                               err.args[0])
 230         else:
 231             self.fail("import by path didn't raise an exception")
 232
 233 class TestPycRewriting(unittest.TestCase):
 234     # Test that the `co_filename` attribute on code objects always points
 235     # to the right file, even when various things happen (e.g. both the .py
 236     # and the .pyc file are renamed).
 237
 238     module_name = "unlikely_module_name"
 239     module_source = """
 240 import sys
 241 code_filename = sys._getframe().f_code.co_filename
 242 module_filename = __file__
 243 constant = 1
 244 def func():
 245     pass
 246 func_filename = func.__code__.co_filename
 247 """
 248     dir_name = os.path.abspath(TESTFN)
 249     file_name = os.path.join(dir_name, module_name) + os.extsep + "py"
 250     compiled_name = file_name + ("c" if __debug__ else "o")
 251
 252     def setUp(self):
 253         self.sys_path = sys.path[:]
 254         self.orig_module = sys.modules.pop(self.module_name, None)
 255         os.mkdir(self.dir_name)
 256         with open(self.file_name, "w") as f:
 257             f.write(self.module_source)
 258         sys.path.insert(0, self.dir_name)
 259
 260     def tearDown(self):
 261         sys.path[:] = self.sys_path
 262         if self.orig_module is not None:
 263             sys.modules[self.module_name] = self.orig_module
 264         else:
 265             del sys.modules[self.module_name]
 266         for file_name in self.file_name, self.compiled_name:
 267             if os.path.exists(file_name):
 268                 os.remove(file_name)
 269         if os.path.exists(self.dir_name):
 270             shutil.rmtree(self.dir_name)
 271
 272     def import_module(self):
 273         ns = globals()
 274         __import__(self.module_name, ns, ns)
 275         return sys.modules[self.module_name]
 276
 277     def test_basics(self):
 278         mod = self.import_module()
 279         self.assertEqual(mod.module_filename, self.file_name)
 280         self.assertEqual(mod.code_filename, self.file_name)
 281         self.assertEqual(mod.func_filename, self.file_name)
 282         del sys.modules[self.module_name]
 283         mod = self.import_module()
 284         self.assertEqual(mod.module_filename, self.file_name)
 285         self.assertEqual(mod.code_filename, self.file_name)
 286         self.assertEqual(mod.func_filename, self.file_name)
 287
 288     def test_incorrect_code_name(self):
 289         py_compile.compile(self.file_name, dfile="another_module.py")
 290         mod = self.import_module()
 291         self.assertEqual(mod.module_filename, self.file_name)
 292         self.assertEqual(mod.code_filename, self.file_name)
 293         self.assertEqual(mod.func_filename, self.file_name)
 294
 295     def test_module_without_source(self):
 296         target = "another_module.py"
 297         py_compile.compile(self.file_name, dfile=target)
 298         os.remove(self.file_name)
 299         mod = self.import_module()
 300         self.assertEqual(mod.module_filename, self.compiled_name)
 301         self.assertEqual(mod.code_filename, target)
 302         self.assertEqual(mod.func_filename, target)
 303
 304     def test_foreign_code(self):
 305         py_compile.compile(self.file_name)
 306         with open(self.compiled_name, "rb") as f:
 307             header = f.read(8)
 308             code = marshal.load(f)
 309         constants = list(code.co_consts)
 310         foreign_code = test_main.__code__
 311         pos = constants.index(1)
 312         constants[pos] = foreign_code
 313         code = type(code)(code.co_argcount, code.co_kwonlyargcount,
 314                           code.co_nlocals, code.co_stacksize,
 315                           code.co_flags, code.co_code, tuple(constants),
 316                           code.co_names, code.co_varnames, code.co_filename,
 317                           code.co_name, code.co_firstlineno, code.co_lnotab,
 318                           code.co_freevars, code.co_cellvars)
 319         with open(self.compiled_name, "wb") as f:
 320             f.write(header)
 321             marshal.dump(code, f)
 322         mod = self.import_module()
 323         self.assertEqual(mod.constant.co_filename, foreign_code.co_filename)
 324
 325 class PathsTests(unittest.TestCase):
 326     SAMPLES = ('test', 'test\u00e4\u00f6\u00fc\u00df', 'test\u00e9\u00e8',
 327                'test\u00b0\u00b3\u00b2')
 328     path = TESTFN
 329
 330     def setUp(self):
 331         os.mkdir(self.path)
 332         self.syspath = sys.path[:]
 333
 334     def tearDown(self):
 335         shutil.rmtree(self.path)
 336         sys.path = self.syspath
 337
 338     # http://bugs.python.org/issue1293
 339     def test_trailing_slash(self):
 340         f = open(os.path.join(self.path, 'test_trailing_slash.py'), 'w')
 341         f.write("testdata = 'test_trailing_slash'")
 342         f.close()
 343         sys.path.append(self.path+'/')
 344         mod = __import__("test_trailing_slash")
 345         self.assertEqual(mod.testdata, 'test_trailing_slash')
 346         unload("test_trailing_slash")
 347
 348     # http://bugs.python.org/issue3677
 349     def _test_UNC_path(self):
 350         f = open(os.path.join(self.path, 'test_trailing_slash.py'), 'w')
 351         f.write("testdata = 'test_trailing_slash'")
 352         f.close()
 353         #create the UNC path, like \\myhost\c$\foo\bar
 354         path = os.path.abspath(self.path)
 355         import socket
 356         hn = socket.gethostname()
 357         drive = path[0]
 358         unc = "\\\\%s\\%s$"%(hn, drive)
 359         unc += path[2:]
 360         sys.path.append(path)
 361         mod = __import__("test_trailing_slash")
 362         self.assertEqual(mod.testdata, 'test_trailing_slash')
 363         unload("test_trailing_slash")
 364
 365     if sys.platform == "win32":
 366         test_UNC_path = _test_UNC_path
 367
 368
 369 class RelativeImport(unittest.TestCase):
 370     def tearDown(self):
 371         try:
 372             del sys.modules["test.relimport"]
 373         except:
 374             pass
 375
 376     def test_relimport_star(self):
 377         # This will import * from .test_import.
 378         from . import relimport
 379         self.assertTrue(hasattr(relimport, "RelativeImport"))
 380
 381     def test_issue3221(self):
 382         # Note for mergers: the 'absolute' tests from the 2.x branch
 383         # are missing in Py3k because implicit relative imports are
 384         # a thing of the past
 385         def check_relative():
 386             exec("from . import relimport", ns)
 387         # Check relative import OK with __package__ and __name__ correct
 388         ns = dict(__package__='test', __name__='test.notarealmodule')
 389         check_relative()
 390         # Check relative import OK with only __name__ wrong
 391         ns = dict(__package__='test', __name__='notarealpkg.notarealmodule')
 392         check_relative()
 393         # Check relative import fails with only __package__ wrong
 394         ns = dict(__package__='foo', __name__='test.notarealmodule')
 395         self.assertRaises(SystemError, check_relative)
 396         # Check relative import fails with __package__ and __name__ wrong
 397         ns = dict(__package__='foo', __name__='notarealpkg.notarealmodule')
 398         self.assertRaises(SystemError, check_relative)
 399         # Check relative import fails with package set to a non-string
 400         ns = dict(__package__=object())
 401         self.assertRaises(ValueError, check_relative)
 402
 403 def test_main(verbose=None):
 404     run_unittest(ImportTest, TestPycRewriting, PathsTests, RelativeImport)
 405
 406 if __name__ == '__main__':
 407     # test needs to be a package, so we can do relative import
 408     from test.test_import import test_main
 409     test_main()