finder.py 文件源码

def _InternalImportModule(self, name, deferredImports, namespace = False):
        """Internal method used for importing a module which assumes that the
           name given is an absolute name. None is returned if the module
           cannot be found."""
        try:
            # Check in module cache before trying to import it again.
            return self._modules[name]
        except KeyError:
            pass

        if name in self._builtinModules:
            module = self._AddModule(name)
            logging.debug("Adding module [%s] [C_BUILTIN]", name)
            self._RunHook("load", module.name, module)
            module.inImport = False
            return module

        pos = name.rfind(".")
        if pos < 0:  # Top-level module
            path = self.path
            searchName = name
            parentModule = None
        else:        # Dotted module name - look up the parent module
            parentName = name[:pos]
            parentModule = \
                    self._InternalImportModule(parentName, deferredImports,
                            namespace = namespace)
            if parentModule is None:
                return None
            if namespace:
                parentModule.ExtendPath()
            path = parentModule.path
            searchName = name[pos + 1:]

        if name in self.aliases:
            actualName = self.aliases[name]
            module = self._InternalImportModule(actualName, deferredImports)
            self._modules[name] = module
            return module

        try:
            fp, path, info = self._FindModule(searchName, path, namespace)
            if info[-1] == imp.C_BUILTIN and parentModule is not None:
                return None
            module = self._LoadModule(name, fp, path, info, deferredImports,
                    parentModule, namespace)
        except ImportError:
            logging.debug("Module [%s] cannot be imported", name)
            self._modules[name] = None
            return None
        return module