python extract_msg模块 -env-3.7 - .tokenize_rtf - 无效的语法错误

问：

在 okenizeRTF python 3.7 中获取语法错误。请指教

from .tokenize_rtf import tokenizeRTF

错误：

  File "C:\Users\vvv\Miniconda3\envs\env-py37\lib\site-packages\extract_msg\_rtf\tokenize_rtf.py", line 68
    while (nextChar:= reader.read(1)) != b'' and nextChar.isalpha():
                   ^
SyntaxError: invalid syntax

只需 2 行

import extract_msg

msg=extract_msg.Message('testmessage.msg')