Python __import__函数代码示例

    def init_func(self, creator_fd, raw_socket_fd, tun_fd, cs, caddr, debug=True):
        self.__debug = debug
        self.__caddr = caddr

        name = "freenet.lib.crypto.%s" % fns_config.configs["tcp_crypto_module"]["name"]
        __import__(name)

        crypto = sys.modules[name]

        args = fns_config.configs["tcp_crypto_module"]["args"]

        self.__encrypt = crypto.encrypt(*args)
        self.__decrypt = crypto.decrypt(*args)
        self.__creator_fd = creator_fd
        self.__traffic_send_fd = raw_socket_fd
        self.__vlan_ips = []
        self.__udp_natp_to_fd = {}
        self.__tun_fd = tun_fd

        self.set_socket(cs)

        self.register(self.fileno)
        self.add_evt_read(self.fileno)

        self.set_timeout(self.fileno, self.__TIMEOUT_NO_AUTH)
        self.print_access_log("connect")

        return self.fileno

def get_versions(module_list=None):
    if not module_list:
        return {}

    ext_module_list = set()
    for m in module_list:
        parts = m.split('.')
        ext_module_list.update('.'.join(parts[:idx])
                               for idx in range(1, len(parts) + 1))

    versions = {}
    for module_name in ext_module_list:
        if module_name not in _VERSION_CACHE:
            try:
                __import__(module_name)
            except ImportError:
                continue

            try:
                app = sys.modules[module_name]
            except KeyError:
                continue

            try:
                version = get_version_from_app(module_name, app)
            except Exception as e:
                logger.exception(e)
                version = None

            _VERSION_CACHE[module_name] = version
        else:
            version = _VERSION_CACHE[module_name]
        if version is not None:
            versions[module_name] = version
    return versions

    def wrap(f):
        if modules:
            # attach import to function
            setattr(f, 'imports', modules)
            for alternatives in modules:
                # alternatives are comma seperated
                alternatives = alternatives.split(',')
                # we import the part of the import X.Y.Z -> Z
                mod_name = alternatives[0].split('.')[-1]
                for mod in alternatives:
                    mod = mod.strip().split('.')

                    try:
                        if len(mod) == 1:
                            module = __import__(mod[0])
                        else:
                            module = getattr(__import__('.'.join(mod[:-1]), \
                                            fromlist=[mod[-1]]), mod[-1])
                        f.func_globals[mod_name] = module
                        break # import only one
                    except ImportError:
                        pass
                else:
                    if forgive: # no break -> no import
                        warnings.warn('Failed to import %s' % alternatives)
                    else:
                        raise ImportError('Failed to import %s' % alternatives)
        return f

def module_exists(module_name):
    try:
        __import__(module_name)
    except ImportError:
        return False
    else:
        return True

def load_module(module_name):
  """Imports a module given its name and returns a handle to it."""
  try:
    __import__(module_name)
  except ImportError:
    raise ImportError('No module named %s' % module_name)
  return sys.modules[module_name]

 def wrap(*args, **kwargs):
     __import__('time').sleep(seconds)
     try:
         result = target(*args, **kwargs)
     except:
         result = None
     return result

def import_module(module_name):
    """
    Imports a module. A single point of truth for importing modules to
    be documented by `pdoc`. In particular, it makes sure that the top
    module in `module_name` can be imported by using only the paths in
    `pdoc.import_path`.

    If a module has already been imported, then its corresponding entry
    in `sys.modules` is returned. This means that modules that have
    changed on disk cannot be re-imported in the same process and have
    its documentation updated.
    """
    if import_path != sys.path:
        # Such a kludge. Only restrict imports if the `import_path` has
        # been changed. We don't want to always restrict imports, since
        # providing a path to `imp.find_module` stops it from searching
        # in special locations for built ins or frozen modules.
        #
        # The problem here is that this relies on the `sys.path` not being
        # independently changed since the initialization of this module.
        # If it is changed, then some packages may fail.
        #
        # Any other options available?

        # Raises an exception if the parent module cannot be imported.
        # This hopefully ensures that we only explicitly import modules
        # contained in `pdoc.import_path`.
        imp.find_module(module_name.split('.')[0], import_path)

    if module_name in sys.modules:
        return sys.modules[module_name]
    else:
        __import__(module_name)
        return sys.modules[module_name]

    def getargs(self,moduleName,className,method) :
        '''
          This will return the list of arguments in a method of python module of class.
          It accepts method list as an argument.
        '''
        print "Message : Argument list is being obtained for each method"
        methodArgsDict = {}
        if className == None:
            moduleList = moduleName.split(".")
            for index,name in enumerate(method) :
                Module = __import__(moduleList[len(moduleList) -1], globals(), locals(), [moduleList[len(moduleList) -2]], -1)
                try :
                    names = vars(Module)[name]
                except KeyError:
                    print "Message : method '" + name + "'does not exists,Continued with including it. "
                    return False
                argumentList = inspect.getargspec(names) #inspect.getargvalues(name)
                methodArgsDict[name] = argumentList[0]
        else :
            moduleList = moduleName.split(".")
            for index,name in enumerate(method) :
                Module = __import__(moduleList[len(moduleList) - 1], globals(), locals(), [className], -1)
                Class = getattr(Module, className)
                try :
                    names = vars(Class)[name]
                except KeyError :
                    print "Message : method '" + name + "'does not exists,Continued with include it."
                    return False

                argumentList = inspect.getargspec(names) #inspect.getargvalues(name)
                methodArgsDict[name] = argumentList[0]

        return methodArgsDict

def check_config(dbdriver, dbtype, dbhost, dbuser, dbpasswd, testdb):
    global DBDRIVER, DBTYPE, DBHOST, DBUSER, DBPASSWD, TESTDB, DBSCHEMA, SQL_FILE
    DBDRIVER = dbdriver
    DBTYPE = dbtype
    DBHOST = dbhost
    DBUSER = dbuser
    DBPASSWD = dbpasswd
    TESTDB = testdb

    #Check the database driver is installed:
    try:
        __import__(DBDRIVER)
    except ImportError:
        message = "Install %s if you want to use %s with BioSQL " % (DBDRIVER, DBTYPE)
        raise MissingExternalDependencyError(message)

    try:
        if DBDRIVER in ["sqlite3"]:
            server = BioSeqDatabase.open_database(driver = DBDRIVER, db = TESTDB)
        else:
            server = BioSeqDatabase.open_database(driver = DBDRIVER,
                                                  user = DBUSER, passwd = DBPASSWD,
                                                  host = DBHOST)
            server.close()
            del server
    except Exception, e:
        message = "Connection failed, check settings if you plan to use BioSQL: %s" % str(e)
        raise MissingExternalDependencyError(message)

    def test_package_import__semantics(self):

        # Generate a couple of broken modules to try importing.

        # ...try loading the module when there's a SyntaxError
        self.rewrite_file('for')
        try: __import__(self.module_name)
        except SyntaxError: pass
        else: raise RuntimeError, 'Failed to induce SyntaxError'
        self.assertNotIn(self.module_name, sys.modules)
        self.assertFalse(hasattr(sys.modules[self.package_name], 'foo'))

        # ...make up a variable name that isn't bound in __builtins__
        var = 'a'
        while var in dir(__builtins__):
            var += random.choose(string.letters)

        # ...make a module that just contains that
        self.rewrite_file(var)

        try: __import__(self.module_name)
        except NameError: pass
        else: raise RuntimeError, 'Failed to induce NameError.'

        # ...now  change  the module  so  that  the NameError  doesn't
        # happen
        self.rewrite_file('%s = 1' % var)
        module = __import__(self.module_name).foo
        self.assertEqual(getattr(module, var), 1)

    def getmethods(self,modulePath,Class) :
        '''
         This will get the list of methods in given module or class.
         It accepts the module path and class name. If there is no
         class name then it has be mentioned as None.
        '''
        methodList = []
        moduleList = modulePath.split("/")
        newModule = ".".join([moduleList[len(moduleList) - 2],moduleList[len(moduleList) - 1]])
        print "Message : Method list is being obatined , Please wait ..."
        try :
            if Class :
                Module = __import__(moduleList[len(moduleList) - 1], globals(), locals(), [Class], -1)
                ClassList = [x.__name__ for x in Module.__dict__.values() if inspect.isclass(x)]
                self.ClassList = ClassList
                Class = vars(Module)[Class]
                methodList = [x.__name__ for x in Class.__dict__.values() if inspect.isfunction(x)]
            else :
                Module = __import__(moduleList[len(moduleList) - 1], globals(), locals(),[moduleList[len(moduleList) - 2]], -1)
                methodList = [x.__name__ for x in Module.__dict__.values() if inspect.isfunction(x)]
                ClassList = [x.__name__ for x in Module.__dict__.values() if inspect.isclass(x)]
                self.ClassList = ClassList
        except :
            print "Error : " +str(sys.exc_info()[1])


        self.method = methodList
        return self.method

def main(listener_fd, alive_r, preload, main_path=None, sys_path=None):
    '''Run forkserver.'''
    if preload:
        if '__main__' in preload and main_path is not None:
            process.current_process()._inheriting = True
            try:
                spawn.import_main_path(main_path)
            finally:
                del process.current_process()._inheriting
        for modname in preload:
            try:
                __import__(modname)
            except ImportError:
                pass

    util._close_stdin()

    # ignoring SIGCHLD means no need to reap zombie processes
    # letting SIGINT through avoids KeyboardInterrupt tracebacks
    handlers = {
        signal.SIGCHLD: signal.SIG_IGN,
        signal.SIGINT: signal.SIG_DFL,
        }
    old_handlers = {sig: signal.signal(sig, val)
                    for (sig, val) in handlers.items()}

    with socket.socket(socket.AF_UNIX, fileno=listener_fd) as listener, \
         selectors.DefaultSelector() as selector:
        _forkserver._forkserver_address = listener.getsockname()

        selector.register(listener, selectors.EVENT_READ)
        selector.register(alive_r, selectors.EVENT_READ)

        while True:
            try:
                while True:
                    rfds = [key.fileobj for (key, events) in selector.select()]
                    if rfds:
                        break

                if alive_r in rfds:
                    # EOF because no more client processes left
                    assert os.read(alive_r, 1) == b''
                    raise SystemExit

                assert listener in rfds
                with listener.accept()[0] as s:
                    code = 1
                    if os.fork() == 0:
                        try:
                            _serve_one(s, listener, alive_r, old_handlers)
                        except Exception:
                            sys.excepthook(*sys.exc_info())
                            sys.stderr.flush()
                        finally:
                            os._exit(code)

            except OSError as e:
                if e.errno != errno.ECONNABORTED:
                    raise

def import_backends():
    """
    Import files in the duplicity/backends directory where
    the filename ends in 'backend.py' and ignore the rest.

    @rtype: void
    @return: void
    """
    path = duplicity.backends.__path__[0]
    assert path.endswith("duplicity/backends"), duplicity.backends.__path__

    files = os.listdir(path)
    files.sort()
    for fn in files:
        if fn.endswith("backend.py"):
            fn = fn[:-3]
            imp = "duplicity.backends.%s" % (fn,)
            try:
                __import__(imp)
                res = "Succeeded"
            except Exception:
                res = "Failed: " + str(sys.exc_info()[1])
            log.Log(_("Import of %s %s") % (imp, res), log.INFO)
        else:
            continue

def get_config(config_path):
    __import__('errbot.config-template')  # - is on purpose, it should not be imported normally ;)
    template = sys.modules['errbot.config-template']
    config_fullpath = config_path
    if not path.exists(config_fullpath):
        log.error(
            'I cannot find the file %s \n'
            '(You can change this path with the -c parameter see --help)' % config_path
        )
        log.info(
            'You can use the template %s as a base and copy it to %s. \nYou can then customize it.' % (
                path.dirname(template.__file__) + sep + 'config-template.py', config_path + sep)
        )
        exit(-1)

    # noinspection PyBroadException
    try:
        config = __import__(path.splitext(path.basename(config_fullpath))[0])

        diffs = [item for item in set(dir(template)) - set(dir(config)) if not item.startswith('_')]
        if diffs:
            log.error('You are missing configs defined from the template :')
            for diff in diffs:
                log.error('Missing config : %s' % diff)
            exit(-1)
    except Exception as _:
        log.exception('I could not import your config from %s, please check the error below...' % config_fullpath)
        exit(-1)
    log.info('Config check passed...')
    return config

    def find_controller(self, controller):
        """Locates a controller by attempting to import it then grab
        the SomeController instance from the imported module.

        Override this to change how the controller object is found once
        the URL has been resolved.

        """
        # Check to see if we've cached the class instance for this name
        if controller in self.controller_classes:
            return self.controller_classes[controller]

        # Pull the controllers class name, import controller
        full_module_name = self.package_name + '.controllers.' \
            + controller.replace('/', '.')

        # Hide the traceback here if the import fails (bad syntax and such)
        __traceback_hide__ = 'before_and_this'

        __import__(full_module_name)
        if hasattr(sys.modules[full_module_name], '__controller__'):
            mycontroller = getattr(
                sys.modules[full_module_name],
                sys.modules[full_module_name].__controller__)
        else:
            module_name = controller.split('/')[-1]
            class_name = class_name_from_module_name(module_name) + \
                'Controller'
            if self.log_debug:
                log.debug("Found controller, module: '%s', class: '%s'",
                          full_module_name, class_name)
            mycontroller = getattr(sys.modules[full_module_name], class_name)
        self.controller_classes[controller] = mycontroller
        return mycontroller