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 marshal
   9 from test.test_support import unlink, TESTFN, unload, run_unittest, check_warnings
  10
  11
  12 def remove_files(name):
  13     for f in (name + os.extsep + "py",
  14               name + os.extsep + "pyc",
  15               name + os.extsep + "pyo",
  16               name + os.extsep + "pyw",
  17               name + "$py.class"):
  18         if os.path.exists(f):
  19             os.remove(f)
  20
  21
  22 class ImportTest(unittest.TestCase):
  23
  24     def testCaseSensitivity(self):
  25         # Brief digression to test that import is case-sensitive:  if we got this
  26         # far, we know for sure that "random" exists.
  27         try:
  28             import RAnDoM
  29         except ImportError:
  30             pass
  31         else:
  32             self.fail("import of RAnDoM should have failed (case mismatch)")
  33
  34     def testDoubleConst(self):
  35         # Another brief digression to test the accuracy of manifest float constants.
  36         from test import double_const  # don't blink -- that *was* the test
  37
  38     def testImport(self):
  39         def test_with_extension(ext):
  40             # ext normally ".py"; perhaps ".pyw"
  41             source = TESTFN + ext
  42             pyo = TESTFN + os.extsep + "pyo"
  43             if sys.platform.startswith('java'):
  44                 pyc = TESTFN + "$py.class"
  45             else:
  46                 pyc = TESTFN + os.extsep + "pyc"
  47
  48             f = open(source, "w")
  49             print >> f, "# This tests Python's ability to import a", ext, "file."
  50             a = random.randrange(1000)
  51             b = random.randrange(1000)
  52             print >> f, "a =", a
  53             print >> f, "b =", b
  54             f.close()
  55
  56             try:
  57                 try:
  58                     mod = __import__(TESTFN)
  59                 except ImportError, err:
  60                     self.fail("import from %s failed: %s" % (ext, err))
  61
  62                 self.assertEquals(mod.a, a,
  63                     "module loaded (%s) but contents invalid" % mod)
  64                 self.assertEquals(mod.b, b,
  65                     "module loaded (%s) but contents invalid" % mod)
  66             finally:
  67                 os.unlink(source)
  68
  69             try:
  70                 try:
  71                     reload(mod)
  72                 except ImportError, err:
  73                     self.fail("import from .pyc/.pyo failed: %s" % err)
  74             finally:
  75                 try:
  76                     os.unlink(pyc)
  77                 except OSError:
  78                     pass
  79                 try:
  80                     os.unlink(pyo)
  81                 except OSError:
  82                     pass
  83                 del sys.modules[TESTFN]
  84
  85         sys.path.insert(0, os.curdir)
  86         try:
  87             test_with_extension(os.extsep + "py")
  88             if sys.platform.startswith("win"):
  89                 for ext in ".PY", ".Py", ".pY", ".pyw", ".PYW", ".pYw":
  90                     test_with_extension(ext)
  91         finally:
  92             del sys.path[0]
  93
  94     def testImpModule(self):
  95         # Verify that the imp module can correctly load and find .py files
  96         import imp
  97         x = imp.find_module("os")
  98         os = imp.load_module("os", *x)
  99
 100     def test_module_with_large_stack(self, module='longlist'):
 101         # create module w/list of 65000 elements to test bug #561858
 102         filename = module + os.extsep + 'py'
 103
 104         # create a file with a list of 65000 elements
 105         f = open(filename, 'w+')
 106         f.write('d = [\n')
 107         for i in range(65000):
 108             f.write('"",\n')
 109         f.write(']')
 110         f.close()
 111
 112         # compile & remove .py file, we only need .pyc (or .pyo)
 113         f = open(filename, 'r')
 114         py_compile.compile(filename)
 115         f.close()
 116         os.unlink(filename)
 117
 118         # need to be able to load from current dir
 119         sys.path.append('')
 120
 121         # this used to crash
 122         exec 'import ' + module
 123
 124         # cleanup
 125         del sys.path[-1]
 126         for ext in 'pyc', 'pyo':
 127             fname = module + os.extsep + ext
 128             if os.path.exists(fname):
 129                 os.unlink(fname)
 130
 131     def test_failing_import_sticks(self):
 132         source = TESTFN + os.extsep + "py"
 133         f = open(source, "w")
 134         print >> f, "a = 1/0"
 135         f.close()
 136
 137         # New in 2.4, we shouldn't be able to import that no matter how often
 138         # we try.
 139         sys.path.insert(0, os.curdir)
 140         try:
 141             for i in 1, 2, 3:
 142                 try:
 143                     mod = __import__(TESTFN)
 144                 except ZeroDivisionError:
 145                     if TESTFN in sys.modules:
 146                         self.fail("damaged module in sys.modules on %i. try" % i)
 147                 else:
 148                     self.fail("was able to import a damaged module on %i. try" % i)
 149         finally:
 150             sys.path.pop(0)
 151             remove_files(TESTFN)
 152
 153     def test_failing_reload(self):
 154         # A failing reload should leave the module object in sys.modules.
 155         source = TESTFN + os.extsep + "py"
 156         f = open(source, "w")
 157         print >> f, "a = 1"
 158         print >> f, "b = 2"
 159         f.close()
 160
 161         sys.path.insert(0, os.curdir)
 162         try:
 163             mod = __import__(TESTFN)
 164             self.assert_(TESTFN in sys.modules, "expected module in sys.modules")
 165             self.assertEquals(mod.a, 1, "module has wrong attribute values")
 166             self.assertEquals(mod.b, 2, "module has wrong attribute values")
 167
 168             # On WinXP, just replacing the .py file wasn't enough to
 169             # convince reload() to reparse it.  Maybe the timestamp didn't
 170             # move enough.  We force it to get reparsed by removing the
 171             # compiled file too.
 172             remove_files(TESTFN)
 173
 174             # Now damage the module.
 175             f = open(source, "w")
 176             print >> f, "a = 10"
 177             print >> f, "b = 20//0"
 178             f.close()
 179
 180             self.assertRaises(ZeroDivisionError, reload, mod)
 181
 182             # But we still expect the module to be in sys.modules.
 183             mod = sys.modules.get(TESTFN)
 184             self.failIf(mod is None, "expected module to still be in sys.modules")
 185
 186             # We should have replaced a w/ 10, but the old b value should
 187             # stick.
 188             self.assertEquals(mod.a, 10, "module has wrong attribute values")
 189             self.assertEquals(mod.b, 2, "module has wrong attribute values")
 190
 191         finally:
 192             sys.path.pop(0)
 193             remove_files(TESTFN)
 194             if TESTFN in sys.modules:
 195                 del sys.modules[TESTFN]
 196
 197     def test_infinite_reload(self):
 198         # Bug #742342 reports that Python segfaults (infinite recursion in C)
 199         #  when faced with self-recursive reload()ing.
 200
 201         sys.path.insert(0, os.path.dirname(__file__))
 202         try:
 203             import infinite_reload
 204         finally:
 205             sys.path.pop(0)
 206
 207     def test_import_name_binding(self):
 208         # import x.y.z binds x in the current namespace
 209         import test as x
 210         import test.test_support
 211         self.assert_(x is test, x.__name__)
 212         self.assert_(hasattr(test.test_support, "__file__"))
 213
 214         # import x.y.z as w binds z as w
 215         import test.test_support as y
 216         self.assert_(y is test.test_support, y.__name__)
 217
 218     def test_import_initless_directory_warning(self):
 219         with warnings.catch_warnings():
 220             # Just a random non-package directory we always expect to be
 221             # somewhere in sys.path...
 222             warnings.simplefilter('error', ImportWarning)
 223             self.assertRaises(ImportWarning, __import__, "site-packages")
 224
 225     def test_importbyfilename(self):
 226         path = os.path.abspath(TESTFN)
 227         try:
 228             __import__(path)
 229         except ImportError, err:
 230             self.assertEqual("Import by filename is not supported.",
 231                               err.args[0])
 232         else:
 233             self.fail("import by path didn't raise an exception")
 234
 235 class TestPycRewriting(unittest.TestCase):
 236     # Test that the `co_filename` attribute on code objects always points
 237     # to the right file, even when various things happen (e.g. both the .py
 238     # and the .pyc file are renamed).
 239
 240     module_name = "unlikely_module_name"
 241     module_source = """
 242 import sys
 243 code_filename = sys._getframe().f_code.co_filename
 244 module_filename = __file__
 245 constant = 1
 246 def func():
 247     pass
 248 func_filename = func.func_code.co_filename
 249 """
 250     dir_name = os.path.abspath(TESTFN)
 251     file_name = os.path.join(dir_name, module_name) + os.extsep + "py"
 252     compiled_name = file_name + ("c" if __debug__ else "o")
 253
 254     def setUp(self):
 255         self.sys_path = sys.path[:]
 256         self.orig_module = sys.modules.pop(self.module_name, None)
 257         os.mkdir(self.dir_name)
 258         with open(self.file_name, "w") as f:
 259             f.write(self.module_source)
 260         sys.path.insert(0, self.dir_name)
 261
 262     def tearDown(self):
 263         sys.path[:] = self.sys_path
 264         if self.orig_module is not None:
 265             sys.modules[self.module_name] = self.orig_module
 266         else:
 267             del sys.modules[self.module_name]
 268         for file_name in self.file_name, self.compiled_name:
 269             if os.path.exists(file_name):
 270                 os.remove(file_name)
 271         if os.path.exists(self.dir_name):
 272             shutil.rmtree(self.dir_name)
 273
 274     def import_module(self):
 275         ns = globals()
 276         __import__(self.module_name, ns, ns)
 277         return sys.modules[self.module_name]
 278
 279     def test_basics(self):
 280         mod = self.import_module()
 281         self.assertEqual(mod.module_filename, self.file_name)
 282         self.assertEqual(mod.code_filename, self.file_name)
 283         self.assertEqual(mod.func_filename, self.file_name)
 284         del sys.modules[self.module_name]
 285         mod = self.import_module()
 286         self.assertEqual(mod.module_filename, self.compiled_name)
 287         self.assertEqual(mod.code_filename, self.file_name)
 288         self.assertEqual(mod.func_filename, self.file_name)
 289
 290     def test_incorrect_code_name(self):
 291         py_compile.compile(self.file_name, dfile="another_module.py")
 292         mod = self.import_module()
 293         self.assertEqual(mod.module_filename, self.compiled_name)
 294         self.assertEqual(mod.code_filename, self.file_name)
 295         self.assertEqual(mod.func_filename, self.file_name)
 296
 297     def test_module_without_source(self):
 298         target = "another_module.py"
 299         py_compile.compile(self.file_name, dfile=target)
 300         os.remove(self.file_name)
 301         mod = self.import_module()
 302         self.assertEqual(mod.module_filename, self.compiled_name)
 303         self.assertEqual(mod.code_filename, target)
 304         self.assertEqual(mod.func_filename, target)
 305
 306     def test_foreign_code(self):
 307         py_compile.compile(self.file_name)
 308         with open(self.compiled_name, "rb") as f:
 309             header = f.read(8)
 310             code = marshal.load(f)
 311         constants = list(code.co_consts)
 312         foreign_code = test_main.func_code
 313         pos = constants.index(1)
 314         constants[pos] = foreign_code
 315         code = type(code)(code.co_argcount, code.co_nlocals, code.co_stacksize,
 316                           code.co_flags, code.co_code, tuple(constants),
 317                           code.co_names, code.co_varnames, code.co_filename,
 318                           code.co_name, code.co_firstlineno, code.co_lnotab,
 319                           code.co_freevars, code.co_cellvars)
 320         with open(self.compiled_name, "wb") as f:
 321             f.write(header)
 322             marshal.dump(code, f)
 323         mod = self.import_module()
 324         self.assertEqual(mod.constant.co_filename, foreign_code.co_filename)
 325
 326 class PathsTests(unittest.TestCase):
 327     path = TESTFN
 328
 329     def setUp(self):
 330         os.mkdir(self.path)
 331         self.syspath = sys.path[:]
 332
 333     def tearDown(self):
 334         shutil.rmtree(self.path)
 335         sys.path = self.syspath
 336
 337     # http://bugs.python.org/issue1293
 338     def test_trailing_slash(self):
 339         f = open(os.path.join(self.path, 'test_trailing_slash.py'), 'w')
 340         f.write("testdata = 'test_trailing_slash'")
 341         f.close()
 342         sys.path.append(self.path+'/')
 343         mod = __import__("test_trailing_slash")
 344         self.assertEqual(mod.testdata, 'test_trailing_slash')
 345         unload("test_trailing_slash")
 346
 347     # http://bugs.python.org/issue3677
 348     def _test_UNC_path(self):
 349         f = open(os.path.join(self.path, 'test_trailing_slash.py'), 'w')
 350         f.write("testdata = 'test_trailing_slash'")
 351         f.close()
 352         #create the UNC path, like \\myhost\c$\foo\bar
 353         path = os.path.abspath(self.path)
 354         import socket
 355         hn = socket.gethostname()
 356         drive = path[0]
 357         unc = "\\\\%s\\%s$"%(hn, drive)
 358         unc += path[2:]
 359         sys.path.append(path)
 360         mod = __import__("test_trailing_slash")
 361         self.assertEqual(mod.testdata, 'test_trailing_slash')
 362         unload("test_trailing_slash")
 363
 364     if sys.platform == "win32":
 365         test_UNC_path = _test_UNC_path
 366
 367
 368 class RelativeImport(unittest.TestCase):
 369     def tearDown(self):
 370         try:
 371             del sys.modules["test.relimport"]
 372         except:
 373             pass
 374
 375     def test_relimport_star(self):
 376         # This will import * from .test_import.
 377         from . import relimport
 378         self.assertTrue(hasattr(relimport, "RelativeImport"))
 379
 380     def test_issue3221(self):
 381         def check_absolute():
 382             exec "from os import path" in ns
 383         def check_relative():
 384             exec "from . import relimport" in ns
 385         # Check both OK with __package__ and __name__ correct
 386         ns = dict(__package__='test', __name__='test.notarealmodule')
 387         check_absolute()
 388         check_relative()
 389         # Check both OK with only __name__ wrong
 390         ns = dict(__package__='test', __name__='notarealpkg.notarealmodule')
 391         check_absolute()
 392         check_relative()
 393         # Check relative fails with only __package__ wrong
 394         ns = dict(__package__='foo', __name__='test.notarealmodule')
 395         with check_warnings() as w:
 396             check_absolute()
 397             self.assert_('foo' in str(w.message))
 398             self.assertEqual(w.category, RuntimeWarning)
 399         self.assertRaises(SystemError, check_relative)
 400         # Check relative fails with __package__ and __name__ wrong
 401         ns = dict(__package__='foo', __name__='notarealpkg.notarealmodule')
 402         with check_warnings() as w:
 403             check_absolute()
 404             self.assert_('foo' in str(w.message))
 405             self.assertEqual(w.category, RuntimeWarning)
 406         self.assertRaises(SystemError, check_relative)
 407         # Check both fail with package set to a non-string
 408         ns = dict(__package__=object())
 409         self.assertRaises(ValueError, check_absolute)
 410         self.assertRaises(ValueError, check_relative)
 411
 412 def test_main(verbose=None):
 413     run_unittest(ImportTest, TestPycRewriting, PathsTests, RelativeImport)
 414
 415 if __name__ == '__main__':
 416     # test needs to be a package, so we can do relative import
 417     from test.test_import import test_main
 418     test_main()