Python importlib.util() Examples

def import_pyjokes_module():
    v = os.environ.get('VIRTUAL_ENV', None)
    if v:
        sys.path = [v + '/lib/python3.5/site-packages'] + sys.path

    if importlib.util.find_spec('pyjokes'):
        return importlib.import_module('pyjokes') 

def test_timestamp_overflow(self):
        # A modification timestamp larger than 2**32 should not be a problem
        # when importing a module (issue #11235).
        sys.path.insert(0, os.curdir)
        try:
            source = TESTFN + ".py"
            compiled = importlib.util.cache_from_source(source)
            with open(source, 'w') as f:
                pass
            try:
                os.utime(source, (2 ** 33 - 5, 2 ** 33 - 5))
            except OverflowError:
                self.skipTest("cannot set modification time to large integer")
            except OSError as e:
                if e.errno not in (getattr(errno, 'EOVERFLOW', None),
                                   getattr(errno, 'EINVAL', None)):
                    raise
                self.skipTest("cannot set modification time to large integer ({})".format(e))
            __import__(TESTFN)
            # The pyc file was created.
            os.stat(compiled)
        finally:
            del sys.path[0]
            remove_files(TESTFN) 

def import_module_by_path(path):
    name = os.path.splitext(os.path.basename(path))[0]
    if sys.version_info[0] == 2:
        import imp
        return imp.load_source(name, path)
    elif sys.version_info[:2] <= (3, 4):
        from importlib.machinery import SourceFileLoader
        return SourceFileLoader(name, path).load_module()
    else:
        import importlib.util
        spec = importlib.util.spec_from_file_location(name, path)
        mod = importlib.util.module_from_spec(spec)
        spec.loader.exec_module(mod)
        return mod


# ===================================================================
# --- others
# =================================================================== 

def test_package___cached__(self):
        # Like test___cached__ but for packages.
        def cleanup():
            rmtree('pep3147')
            unload('pep3147.foo')
            unload('pep3147')
        os.mkdir('pep3147')
        self.addCleanup(cleanup)
        # Touch the __init__.py
        with open(os.path.join('pep3147', '__init__.py'), 'w'):
            pass
        with open(os.path.join('pep3147', 'foo.py'), 'w'):
            pass
        importlib.invalidate_caches()
        m = __import__('pep3147.foo')
        init_pyc = importlib.util.cache_from_source(
            os.path.join('pep3147', '__init__.py'))
        self.assertEqual(m.__cached__, os.path.join(os.curdir, init_pyc))
        foo_pyc = importlib.util.cache_from_source(os.path.join('pep3147', 'foo.py'))
        self.assertEqual(sys.modules['pep3147.foo'].__cached__,
                         os.path.join(os.curdir, foo_pyc)) 

def _check_path_limitations(self, module_name):
        # base directory
        source_path_len = len(self.here)
        # a path separator + `longname` (twice)
        source_path_len += 2 * (len(self.longname) + 1)
        # a path separator + `module_name` + ".py"
        source_path_len += len(module_name) + 1 + len(".py")
        cached_path_len = (source_path_len +
            len(importlib.util.cache_from_source("x.py")) - len("x.py"))
        if os.name == 'nt' and cached_path_len >= 258:
            # Under Windows, the max path len is 260 including C's terminating
            # NUL character.
            # (see http://msdn.microsoft.com/en-us/library/windows/desktop/aa365247%28v=vs.85%29.aspx#maxpath)
            self.skipTest("test paths too long (%d characters) for Windows' 260 character limit"
                          % cached_path_len)
        elif os.name == 'nt' and verbose:
            print("cached_path_len =", cached_path_len) 

def forget(modname):
    """'Forget' a module was ever imported.

    This removes the module from sys.modules and deletes any PEP 3147 or
    legacy .pyc and .pyo files.
    """
    unload(modname)
    for dirname in sys.path:
        source = os.path.join(dirname, modname + '.py')
        # It doesn't matter if they exist or not, unlink all possible
        # combinations of PEP 3147 and legacy pyc and pyo files.
        unlink(source + 'c')
        unlink(source + 'o')
        unlink(importlib.util.cache_from_source(source, debug_override=True))
        unlink(importlib.util.cache_from_source(source, debug_override=False))

# Check whether a gui is actually available 

def _check_path_limitations(self, module_name):
        # base directory
        source_path_len = len(self.here)
        # a path separator + `longname` (twice)
        source_path_len += 2 * (len(self.longname) + 1)
        # a path separator + `module_name` + ".py"
        source_path_len += len(module_name) + 1 + len(".py")
        cached_path_len = (source_path_len +
            len(importlib.util.cache_from_source("x.py")) - len("x.py"))
        if os.name == 'nt' and cached_path_len >= 258:
            # Under Windows, the max path len is 260 including C's terminating
            # NUL character.
            # (see http://msdn.microsoft.com/en-us/library/windows/desktop/aa365247%28v=vs.85%29.aspx#maxpath)
            self.skipTest("test paths too long (%d characters) for Windows' 260 character limit"
                          % cached_path_len)
        elif os.name == 'nt' and verbose:
            print("cached_path_len =", cached_path_len) 

def test_run_name(self):
        depth = 1
        run_name = "And now for something completely different"
        pkg_dir, mod_fname, mod_name, mod_spec = (
               self._make_pkg(example_source, depth))
        forget(mod_name)
        expected_ns = example_namespace.copy()
        expected_ns.update({
            "__name__": run_name,
            "__file__": mod_fname,
            "__cached__": importlib.util.cache_from_source(mod_fname),
            "__package__": mod_name.rpartition(".")[0],
            "__spec__": mod_spec,
        })
        def create_ns(init_globals):
            return run_module(mod_name, init_globals, run_name)
        try:
            self.check_code_execution(create_ns, expected_ns)
        finally:
            self._del_pkg(pkg_dir, depth, mod_name) 

def test_issue24748_load_module_skips_sys_modules_check(self):
        name = 'test.imp_dummy'
        try:
            del sys.modules[name]
        except KeyError:
            pass
        try:
            module = importlib.import_module(name)
            spec = importlib.util.find_spec('_testmultiphase')
            module = imp.load_dynamic(name, spec.origin)
            self.assertEqual(module.__name__, name)
            self.assertEqual(module.__spec__.name, name)
            self.assertEqual(module.__spec__.origin, spec.origin)
            self.assertRaises(AttributeError, getattr, module, 'dummy_name')
            self.assertEqual(module.int_const, 1969)
            self.assertIs(sys.modules[name], module)
        finally:
            try:
                del sys.modules[name]
            except KeyError:
                pass 

def load_module(module_path):
    if "/" not in module_path:
        import importlib

        return importlib.import_module("%s" % module_path, package="armory")
    else:
        module_name = module_path.split("/")[-1]
        if sys.version_info.major == 2:
            import imp

            return imp.load_source(module_name, module_path + ".py")
        else:
            import importlib.util

            spec = importlib.util.spec_from_file_location(
                module_name, module_path + ".py"
            )
            module = importlib.util.module_from_spec(spec)
            spec.loader.exec_module(module)
            return module 

def load_dashboard(path):
    """Load a ``Dashboard`` from a Python definition.

    :param str path: Path to a *.dashboard.py file that defines a variable,
        ``dashboard``.
    :return: A ``Dashboard``
    """
    if sys.version_info[0] == 3 and sys.version_info[1] >= 5:
        import importlib.util
        spec = importlib.util.spec_from_file_location("dashboard", path)
        module = importlib.util.module_from_spec(spec)
        spec.loader.exec_module(module)
    else:
        import importlib
        module = importlib.load_source("dashboard", path)
    marker = object()
    dashboard = getattr(module, 'dashboard', marker)
    if dashboard is marker:
        raise DashboardError(
            "Dashboard definition {} does not define 'dashboard'".format(path))
    return dashboard 

def find_loader(fullname):
    """Find a PEP 302 "loader" object for fullname

    This is a backwards compatibility wrapper around
    importlib.util.find_spec that converts most failures to ImportError
    and only returns the loader rather than the full spec
    """
    if fullname.startswith('.'):
        msg = "Relative module name {!r} not supported".format(fullname)
        raise ImportError(msg)
    try:
        spec = importlib.util.find_spec(fullname)
    except (ImportError, AttributeError, TypeError, ValueError) as ex:
        # This hack fixes an impedance mismatch between pkgutil and
        # importlib, where the latter raises other errors for cases where
        # pkgutil previously raised ImportError
        msg = "Error while finding loader for {!r} ({}: {})"
        raise ImportError(msg.format(fullname, type(ex), ex)) from ex
    return spec.loader if spec is not None else None 

def import_module_by_path(path):
    name = os.path.splitext(os.path.basename(path))[0]
    if sys.version_info[0] == 2:
        import imp
        return imp.load_source(name, path)
    elif sys.version_info[:2] <= (3, 4):
        from importlib.machinery import SourceFileLoader
        return SourceFileLoader(name, path).load_module()
    else:
        import importlib.util
        spec = importlib.util.spec_from_file_location(name, path)
        mod = importlib.util.module_from_spec(spec)
        spec.loader.exec_module(mod)
        return mod


# ===================================================================
# --- others
# =================================================================== 

def find_loader(fullname):
    """Find a "loader" object for fullname

    This is a backwards compatibility wrapper around
    importlib.util.find_spec that converts most failures to ImportError
    and only returns the loader rather than the full spec
    """
    if fullname.startswith('.'):
        msg = "Relative module name {!r} not supported".format(fullname)
        raise ImportError(msg)
    try:
        spec = importlib.util.find_spec(fullname)
    except (ImportError, AttributeError, TypeError, ValueError) as ex:
        # This hack fixes an impedance mismatch between pkgutil and
        # importlib, where the latter raises other errors for cases where
        # pkgutil previously raised ImportError
        msg = "Error while finding loader for {!r} ({}: {})"
        raise ImportError(msg.format(fullname, type(ex), ex)) from ex
    return spec.loader if spec is not None else None 

def find_loader(fullname):
    """Find a PEP 302 "loader" object for fullname

    This is a backwards compatibility wrapper around
    importlib.util.find_spec that converts most failures to ImportError
    and only returns the loader rather than the full spec
    """
    if fullname.startswith('.'):
        msg = "Relative module name {!r} not supported".format(fullname)
        raise ImportError(msg)
    try:
        spec = importlib.util.find_spec(fullname)
    except (ImportError, AttributeError, TypeError, ValueError) as ex:
        # This hack fixes an impedance mismatch between pkgutil and
        # importlib, where the latter raises other errors for cases where
        # pkgutil previously raised ImportError
        msg = "Error while finding loader for {!r} ({}: {})"
        raise ImportError(msg.format(fullname, type(ex), ex)) from ex
    return spec.loader if spec is not None else None 

def get_kwargs(setupfilepath: str):
        setupfilepath = Path(setupfilepath)
        setup_kwargs = {}

        def grab_setup_kwargs(**kwargs):
            setup_kwargs.update(kwargs)

        with chdir(str(setupfilepath.parent)):
            spec = importlib.util.spec_from_file_location(
                "setup", str(setupfilepath.parts[-1])
            )
            with unittest.mock.patch(
                "setuptools.setup", new=grab_setup_kwargs
            ):
                setup = importlib.util.module_from_spec(spec)
                spec.loader.exec_module(setup)

        return setup_kwargs 

def check_fortran_library(path):
    if not path:
        return None

    def _check_library(module):
        spec = importlib.util.spec_from_file_location(module, path)
        try:
            importlib.util.module_from_spec(spec)
        except ImportError:
            return False
        else:
            return True

    if _check_library('pyOM_code'):
        return 'sequential'

    if _check_library('pyOM_code_MPI'):
        return 'parallel'

    return None 

def _importlib_import_modpath(modpath):  # nocover
    """
    Alternative to import_module_from_path using importlib mechainsms
    """
    dpath, rel_modpath = split_modpath(modpath)
    modname = modpath_to_modname(modpath)
    if six.PY2:  # nocover
        import imp
        module = imp.load_source(modname, modpath)
    elif sys.version_info[0:2] <= (3, 4):  # nocover
        if sys.version_info[0:2] <= (3, 2):
            raise AssertionError('3.0 to 3.2 is not supported')
        from importlib.machinery import SourceFileLoader
        module = SourceFileLoader(modname, modpath).load_module()
    else:
        import importlib.util
        spec = importlib.util.spec_from_file_location(modname, modpath)
        module = importlib.util.module_from_spec(spec)
        spec.loader.exec_module(module)
    return module 

def test_functionality(self):
        '''Test basic functionality of stuff defined in an extension module'''
        with util.uncache(self.name):
            module = self.load_module()
            self.assertIsInstance(module, types.ModuleType)
            ex = module.Example()
            self.assertEqual(ex.demo('abcd'), 'abcd')
            self.assertEqual(ex.demo(), None)
            with self.assertRaises(AttributeError):
                ex.abc
            ex.abc = 0
            self.assertEqual(ex.abc, 0)
            self.assertEqual(module.foo(9, 9), 18)
            self.assertIsInstance(module.Str(), str)
            self.assertEqual(module.Str(1) + '23', '123')
            with self.assertRaises(module.error):
                raise module.error()
            self.assertEqual(module.int_const, 1969)
            self.assertEqual(module.str_const, 'something different') 

def test_timestamp_overflow(self):
        # A modification timestamp larger than 2**32 should not be a problem
        # when importing a module (issue #11235).
        sys.path.insert(0, os.curdir)
        try:
            source = TESTFN + ".py"
            compiled = importlib.util.cache_from_source(source)
            with open(source, 'w') as f:
                pass
            try:
                os.utime(source, (2 ** 33 - 5, 2 ** 33 - 5))
            except OverflowError:
                self.skipTest("cannot set modification time to large integer")
            except OSError as e:
                if e.errno != getattr(errno, 'EOVERFLOW', None):
                    raise
                self.skipTest("cannot set modification time to large integer ({})".format(e))
            __import__(TESTFN)
            # The pyc file was created.
            os.stat(compiled)
        finally:
            del sys.path[0]
            remove_files(TESTFN) 

def test_is_package(self):
        self.assertFalse(self.loader.is_package(util.EXTENSIONS.name))
        for suffix in self.machinery.EXTENSION_SUFFIXES:
            path = os.path.join('some', 'path', 'pkg', '__init__' + suffix)
            loader = self.machinery.ExtensionFileLoader('pkg', path)
            self.assertTrue(loader.is_package('pkg')) 

def from_pyfile(self, filename: str, silent: bool = False) -> None:
        """Load the configuration from a Python cfg or py file.

        See Python's ConfigParser docs for details on the cfg format.
        It is a common practice to load the defaults from the source
        using the :meth:`from_object` and then override with a cfg or
        py file, for example

        .. code-block:: python

            app.config.from_object('config_module')
            app.config.from_pyfile('production.cfg')

        Arguments:
            filename: The filename which when appended to
                :attr:`root_path` gives the path to the file

        """
        file_path = self.root_path / filename
        try:
            spec = importlib.util.spec_from_file_location("module.name", file_path)
            if spec is None:  # Likely passed a cfg file
                parser = ConfigParser()
                parser.optionxform = str  # type: ignore # Prevents lowercasing of keys
                with open(file_path) as file_:
                    config_str = "[section]\n" + file_.read()
                parser.read_string(config_str)
                self.from_mapping(parser["section"])
            else:
                module = importlib.util.module_from_spec(spec)
                spec.loader.exec_module(module)  # type: ignore
                self.from_object(module)
        except (FileNotFoundError, IsADirectoryError):
            if not silent:
                raise 

def test_equality(self):
        other = self.machinery.ExtensionFileLoader(util.EXTENSIONS.name,
                                                   util.EXTENSIONS.file_path)
        self.assertEqual(self.loader, other) 

def _get_spec(finder, name):
    """Return the finder-specific module spec."""
    # Works with legacy finders.
    try:
        find_spec = finder.find_spec
    except AttributeError:
        loader = finder.find_module(name)
        if loader is None:
            return None
        return importlib.util.spec_from_loader(name, loader)
    else:
        return find_spec(name) 

def setUp(self):
        self.loader = self.machinery.ExtensionFileLoader(util.EXTENSIONS.name,
                                                         util.EXTENSIONS.file_path) 

def test_reload(self):
        '''Test that reload didn't re-set the module's attributes'''
        with util.uncache(self.name):
            module = self.load_module()
            ex_class = module.Example
            importlib.reload(module)
            self.assertIs(ex_class, module.Example) 

def test_inequality(self):
        other = self.machinery.ExtensionFileLoader('_' + util.EXTENSIONS.name,
                                                   util.EXTENSIONS.file_path)
        self.assertNotEqual(self.loader, other) 

def test_module(self):
        with util.uncache(util.EXTENSIONS.name):
            module = self.load_module(util.EXTENSIONS.name)
            for attr, value in [('__name__', util.EXTENSIONS.name),
                                ('__file__', util.EXTENSIONS.file_path),
                                ('__package__', '')]:
                self.assertEqual(getattr(module, attr), value)
            self.assertIn(util.EXTENSIONS.name, sys.modules)
            self.assertIsInstance(module.__loader__,
                                  self.machinery.ExtensionFileLoader)

    # No extension module as __init__ available for testing. 

def test_module(self):
        '''Test loading an extension module'''
        with util.uncache(self.name):
            module = self.load_module()
            for attr, value in [('__name__', self.name),
                                ('__file__', self.spec.origin),
                                ('__package__', '')]:
                self.assertEqual(getattr(module, attr), value)
            with self.assertRaises(AttributeError):
                module.__path__
            self.assertIs(module, sys.modules[self.name])
            self.assertIsInstance(module.__loader__,
                                  self.machinery.ExtensionFileLoader) 

def setUp(self):
        self.name = '_testmultiphase'
        finder = self.machinery.FileFinder(None)
        self.spec = importlib.util.find_spec(self.name)
        assert self.spec
        self.loader = self.machinery.ExtensionFileLoader(
            self.name, self.spec.origin)

    # No extension module as __init__ available for testing.