def ensure_list(path_or_path_list):
if isinstance(path_or_path_list, (tuple, list, set)):<EOL><INDENT>return [ensure_str(path) for path in path_or_path_list]<EOL><DEDENT>else:<EOL><INDENT>return [ensure_str(path_or_path_list), ]<EOL><DEDENT>
Pre-process input argument, whether if it is:

1. abspath
2. Path instance
3. string
4. list or set of any of them

It returns list of path.

:return path_or_path_list: always return list of path in string

**中文文档**

预处理输入参数。