import sys from num2words import num2words file = sys.argv[1] out_file = sys.argv[2] with open(file) as f: lines = f.readlines() with open(out_file, "w") as fw: for line in lines: key, content = line.strip().split(maxsplit=1) new_content = "" for ct in content.split(): if ct.isdigit(): ct = num2words(ct) new_content += ct + " " fw.write(key + " " + new_content + "\n")