manager.py 文件源码

def ast_from_module_name(self, modname, context_file=None):
        """given a module name, return the astroid object"""
        if modname in self.astroid_cache:
            return self.astroid_cache[modname]
        if modname == '__main__':
            return self._build_stub_module(modname)
        old_cwd = os.getcwd()
        if context_file:
            os.chdir(dirname(context_file))
        try:
            filepath, mp_type = self.file_from_module_name(modname, context_file)
            if mp_type == modutils.PY_ZIPMODULE:
                module = self.zip_import_data(filepath)
                if module is not None:
                    return module
            elif mp_type in (imp.C_BUILTIN, imp.C_EXTENSION):
                if mp_type == imp.C_EXTENSION and not self._can_load_extension(modname):
                    return self._build_stub_module(modname)
                try:
                    module = modutils.load_module_from_name(modname)
                except Exception as ex:
                    msg = 'Unable to load module %s (%s)' % (modname, ex)
                    raise AstroidBuildingException(msg)
                return self.ast_from_module(module, modname)
            elif mp_type == imp.PY_COMPILED:
                raise AstroidBuildingException("Unable to load compiled module %s" % (modname,))
            if filepath is None:
                raise AstroidBuildingException("Unable to load module %s" % (modname,))
            return self.ast_from_file(filepath, modname, fallback=False)
        except AstroidBuildingException as e:
            for hook in self._failed_import_hooks:
                try:
                    return hook(modname)
                except AstroidBuildingException:
                    pass
            raise e
        finally:
            os.chdir(old_cwd)