File Process API
def get_dir_files_as_list(dir_path: str = getcwd(), default_search_file_extension: str = ".json") -> List[str]:
"""
get dir file when end with default_search_file_extension
:param dir_path: which dir we want to walk and get file list
:param default_search_file_extension: which extension we want to search
:return: [] if nothing searched or [file1, file2.... files] file was searched
"""