cpython/Lib/test/test_import.py
Brett Cannon eb3cd301ae Turned out that if you used explicit relative import syntax
(e.g. from .os import sep) and it failed, import would still try the implicit
relative import semantics of an absolute import (from os import sep). That's
not right, so when level is negative, only do explicit relative import
semantics.

Fixes issue #7902. Thanks to Meador Inge for the patch.
2010-05-20 18:37:55 +00:00

453 lines
16 KiB
Python

import imp
import marshal
import os
import py_compile
import random
import shutil
import stat
import sys
import unittest
from test.test_support import (unlink, TESTFN, unload, run_unittest,
is_jython, check_warnings, EnvironmentVarGuard)
def remove_files(name):
for f in (name + os.extsep + "py",
name + os.extsep + "pyc",
name + os.extsep + "pyo",
name + os.extsep + "pyw",
name + "$py.class"):
unlink(f)
class ImportTests(unittest.TestCase):
def tearDown(self):
unload(TESTFN)
setUp = tearDown
def test_case_sensitivity(self):
# Brief digression to test that import is case-sensitive: if we got
# this far, we know for sure that "random" exists.
try:
import RAnDoM
except ImportError:
pass
else:
self.fail("import of RAnDoM should have failed (case mismatch)")
def test_double_const(self):
# Another brief digression to test the accuracy of manifest float
# constants.
from test import double_const # don't blink -- that *was* the test
def test_import(self):
def test_with_extension(ext):
# The extension is normally ".py", perhaps ".pyw".
source = TESTFN + ext
pyo = TESTFN + os.extsep + "pyo"
if is_jython:
pyc = TESTFN + "$py.class"
else:
pyc = TESTFN + os.extsep + "pyc"
with open(source, "w") as f:
print >> f, ("# This tests Python's ability to import a", ext,
"file.")
a = random.randrange(1000)
b = random.randrange(1000)
print >> f, "a =", a
print >> f, "b =", b
try:
mod = __import__(TESTFN)
except ImportError, err:
self.fail("import from %s failed: %s" % (ext, err))
else:
self.assertEqual(mod.a, a,
"module loaded (%s) but contents invalid" % mod)
self.assertEqual(mod.b, b,
"module loaded (%s) but contents invalid" % mod)
finally:
unlink(source)
try:
imp.reload(mod)
except ImportError, err:
self.fail("import from .pyc/.pyo failed: %s" % err)
finally:
unlink(pyc)
unlink(pyo)
unload(TESTFN)
sys.path.insert(0, os.curdir)
try:
test_with_extension(os.extsep + "py")
if sys.platform.startswith("win"):
for ext in [".PY", ".Py", ".pY", ".pyw", ".PYW", ".pYw"]:
test_with_extension(ext)
finally:
del sys.path[0]
@unittest.skipUnless(os.name == 'posix', "test meaningful only on posix systems")
def test_execute_bit_not_copied(self):
# Issue 6070: under posix .pyc files got their execute bit set if
# the .py file had the execute bit set, but they aren't executable.
oldmask = os.umask(022)
sys.path.insert(0, os.curdir)
try:
fname = TESTFN + os.extsep + "py"
f = open(fname, 'w').close()
os.chmod(fname, (stat.S_IRUSR | stat.S_IRGRP | stat.S_IROTH |
stat.S_IXUSR | stat.S_IXGRP | stat.S_IXOTH))
__import__(TESTFN)
fn = fname + 'c'
if not os.path.exists(fn):
fn = fname + 'o'
if not os.path.exists(fn):
self.fail("__import__ did not result in creation of "
"either a .pyc or .pyo file")
s = os.stat(fn)
self.assertEqual(stat.S_IMODE(s.st_mode),
stat.S_IRUSR | stat.S_IRGRP | stat.S_IROTH)
finally:
os.umask(oldmask)
remove_files(TESTFN)
unload(TESTFN)
del sys.path[0]
def test_imp_module(self):
# Verify that the imp module can correctly load and find .py files
# XXX (ncoghlan): It would be nice to use test_support.CleanImport
# here, but that breaks because the os module registers some
# handlers in copy_reg on import. Since CleanImport doesn't
# revert that registration, the module is left in a broken
# state after reversion. Reinitialising the module contents
# and just reverting os.environ to its previous state is an OK
# workaround
orig_path = os.path
orig_getenv = os.getenv
with EnvironmentVarGuard():
x = imp.find_module("os")
new_os = imp.load_module("os", *x)
self.assertIs(os, new_os)
self.assertIs(orig_path, new_os.path)
self.assertIsNot(orig_getenv, new_os.getenv)
def test_module_with_large_stack(self, module='longlist'):
# Regression test for http://bugs.python.org/issue561858.
filename = module + os.extsep + 'py'
# Create a file with a list of 65000 elements.
with open(filename, 'w+') as f:
f.write('d = [\n')
for i in range(65000):
f.write('"",\n')
f.write(']')
# Compile & remove .py file, we only need .pyc (or .pyo).
with open(filename, 'r') as f:
py_compile.compile(filename)
unlink(filename)
# Need to be able to load from current dir.
sys.path.append('')
# This used to crash.
exec 'import ' + module
# Cleanup.
del sys.path[-1]
unlink(filename + 'c')
unlink(filename + 'o')
def test_failing_import_sticks(self):
source = TESTFN + os.extsep + "py"
with open(source, "w") as f:
print >> f, "a = 1 // 0"
# New in 2.4, we shouldn't be able to import that no matter how often
# we try.
sys.path.insert(0, os.curdir)
try:
for i in [1, 2, 3]:
self.assertRaises(ZeroDivisionError, __import__, TESTFN)
self.assertNotIn(TESTFN, sys.modules,
"damaged module in sys.modules on %i try" % i)
finally:
del sys.path[0]
remove_files(TESTFN)
def test_failing_reload(self):
# A failing reload should leave the module object in sys.modules.
source = TESTFN + os.extsep + "py"
with open(source, "w") as f:
print >> f, "a = 1"
print >> f, "b = 2"
sys.path.insert(0, os.curdir)
try:
mod = __import__(TESTFN)
self.assertIn(TESTFN, sys.modules)
self.assertEqual(mod.a, 1, "module has wrong attribute values")
self.assertEqual(mod.b, 2, "module has wrong attribute values")
# On WinXP, just replacing the .py file wasn't enough to
# convince reload() to reparse it. Maybe the timestamp didn't
# move enough. We force it to get reparsed by removing the
# compiled file too.
remove_files(TESTFN)
# Now damage the module.
with open(source, "w") as f:
print >> f, "a = 10"
print >> f, "b = 20//0"
self.assertRaises(ZeroDivisionError, imp.reload, mod)
# But we still expect the module to be in sys.modules.
mod = sys.modules.get(TESTFN)
self.assertIsNot(mod, None, "expected module to be in sys.modules")
# We should have replaced a w/ 10, but the old b value should
# stick.
self.assertEqual(mod.a, 10, "module has wrong attribute values")
self.assertEqual(mod.b, 2, "module has wrong attribute values")
finally:
del sys.path[0]
remove_files(TESTFN)
unload(TESTFN)
def test_infinite_reload(self):
# http://bugs.python.org/issue742342 reports that Python segfaults
# (infinite recursion in C) when faced with self-recursive reload()ing.
sys.path.insert(0, os.path.dirname(__file__))
try:
import infinite_reload
finally:
del sys.path[0]
def test_import_name_binding(self):
# import x.y.z binds x in the current namespace.
import test as x
import test.test_support
self.assertIs(x, test, x.__name__)
self.assertTrue(hasattr(test.test_support, "__file__"))
# import x.y.z as w binds z as w.
import test.test_support as y
self.assertIs(y, test.test_support, y.__name__)
def test_import_initless_directory_warning(self):
with check_warnings(('', ImportWarning)):
# Just a random non-package directory we always expect to be
# somewhere in sys.path...
self.assertRaises(ImportError, __import__, "site-packages")
def test_import_by_filename(self):
path = os.path.abspath(TESTFN)
with self.assertRaises(ImportError) as c:
__import__(path)
self.assertEqual("Import by filename is not supported.",
c.exception.args[0])
class PycRewritingTests(unittest.TestCase):
# Test that the `co_filename` attribute on code objects always points
# to the right file, even when various things happen (e.g. both the .py
# and the .pyc file are renamed).
module_name = "unlikely_module_name"
module_source = """
import sys
code_filename = sys._getframe().f_code.co_filename
module_filename = __file__
constant = 1
def func():
pass
func_filename = func.func_code.co_filename
"""
dir_name = os.path.abspath(TESTFN)
file_name = os.path.join(dir_name, module_name) + os.extsep + "py"
compiled_name = file_name + ("c" if __debug__ else "o")
def setUp(self):
self.sys_path = sys.path[:]
self.orig_module = sys.modules.pop(self.module_name, None)
os.mkdir(self.dir_name)
with open(self.file_name, "w") as f:
f.write(self.module_source)
sys.path.insert(0, self.dir_name)
def tearDown(self):
sys.path[:] = self.sys_path
if self.orig_module is not None:
sys.modules[self.module_name] = self.orig_module
else:
unload(self.module_name)
unlink(self.file_name)
unlink(self.compiled_name)
if os.path.exists(self.dir_name):
shutil.rmtree(self.dir_name)
def import_module(self):
ns = globals()
__import__(self.module_name, ns, ns)
return sys.modules[self.module_name]
def test_basics(self):
mod = self.import_module()
self.assertEqual(mod.module_filename, self.file_name)
self.assertEqual(mod.code_filename, self.file_name)
self.assertEqual(mod.func_filename, self.file_name)
del sys.modules[self.module_name]
mod = self.import_module()
self.assertEqual(mod.module_filename, self.compiled_name)
self.assertEqual(mod.code_filename, self.file_name)
self.assertEqual(mod.func_filename, self.file_name)
def test_incorrect_code_name(self):
py_compile.compile(self.file_name, dfile="another_module.py")
mod = self.import_module()
self.assertEqual(mod.module_filename, self.compiled_name)
self.assertEqual(mod.code_filename, self.file_name)
self.assertEqual(mod.func_filename, self.file_name)
def test_module_without_source(self):
target = "another_module.py"
py_compile.compile(self.file_name, dfile=target)
os.remove(self.file_name)
mod = self.import_module()
self.assertEqual(mod.module_filename, self.compiled_name)
self.assertEqual(mod.code_filename, target)
self.assertEqual(mod.func_filename, target)
def test_foreign_code(self):
py_compile.compile(self.file_name)
with open(self.compiled_name, "rb") as f:
header = f.read(8)
code = marshal.load(f)
constants = list(code.co_consts)
foreign_code = test_main.func_code
pos = constants.index(1)
constants[pos] = foreign_code
code = type(code)(code.co_argcount, code.co_nlocals, code.co_stacksize,
code.co_flags, code.co_code, tuple(constants),
code.co_names, code.co_varnames, code.co_filename,
code.co_name, code.co_firstlineno, code.co_lnotab,
code.co_freevars, code.co_cellvars)
with open(self.compiled_name, "wb") as f:
f.write(header)
marshal.dump(code, f)
mod = self.import_module()
self.assertEqual(mod.constant.co_filename, foreign_code.co_filename)
class PathsTests(unittest.TestCase):
path = TESTFN
def setUp(self):
os.mkdir(self.path)
self.syspath = sys.path[:]
def tearDown(self):
shutil.rmtree(self.path)
sys.path[:] = self.syspath
# Regression test for http://bugs.python.org/issue1293.
def test_trailing_slash(self):
with open(os.path.join(self.path, 'test_trailing_slash.py'), 'w') as f:
f.write("testdata = 'test_trailing_slash'")
sys.path.append(self.path+'/')
mod = __import__("test_trailing_slash")
self.assertEqual(mod.testdata, 'test_trailing_slash')
unload("test_trailing_slash")
# Regression test for http://bugs.python.org/issue3677.
def _test_UNC_path(self):
with open(os.path.join(self.path, 'test_trailing_slash.py'), 'w') as f:
f.write("testdata = 'test_trailing_slash'")
# Create the UNC path, like \\myhost\c$\foo\bar.
path = os.path.abspath(self.path)
import socket
hn = socket.gethostname()
drive = path[0]
unc = "\\\\%s\\%s$"%(hn, drive)
unc += path[2:]
sys.path.append(path)
mod = __import__("test_trailing_slash")
self.assertEqual(mod.testdata, 'test_trailing_slash')
unload("test_trailing_slash")
if sys.platform == "win32":
test_UNC_path = _test_UNC_path
class RelativeImportTests(unittest.TestCase):
def tearDown(self):
unload("test.relimport")
setUp = tearDown
def test_relimport_star(self):
# This will import * from .test_import.
from . import relimport
self.assertTrue(hasattr(relimport, "RelativeImportTests"))
def test_issue3221(self):
# Regression test for http://bugs.python.org/issue3221.
def check_absolute():
exec "from os import path" in ns
def check_relative():
exec "from . import relimport" in ns
# Check both OK with __package__ and __name__ correct
ns = dict(__package__='test', __name__='test.notarealmodule')
check_absolute()
check_relative()
# Check both OK with only __name__ wrong
ns = dict(__package__='test', __name__='notarealpkg.notarealmodule')
check_absolute()
check_relative()
# Check relative fails with only __package__ wrong
ns = dict(__package__='foo', __name__='test.notarealmodule')
with check_warnings(('.+foo', RuntimeWarning)):
check_absolute()
self.assertRaises(SystemError, check_relative)
# Check relative fails with __package__ and __name__ wrong
ns = dict(__package__='foo', __name__='notarealpkg.notarealmodule')
with check_warnings(('.+foo', RuntimeWarning)):
check_absolute()
self.assertRaises(SystemError, check_relative)
# Check both fail with package set to a non-string
ns = dict(__package__=object())
self.assertRaises(ValueError, check_absolute)
self.assertRaises(ValueError, check_relative)
def test_absolute_import_without_future(self):
# If absolute import syntax is used, then do not try to perform
# a relative import in the face of failure.
# Issue #7902.
try:
from .os import sep
except ImportError:
pass
else:
self.fail("explicit relative import triggered an "
"implicit relative import")
def test_main(verbose=None):
run_unittest(ImportTests, PycRewritingTests, PathsTests, RelativeImportTests)
if __name__ == '__main__':
# Test needs to be a package, so we can do relative imports.
from test.test_import import test_main
test_main()