计算文章小说所有汉字总数

我是真无聊呀，不想抄作文呀写个这

import re


def ret(msg):
    num = 0
    pat = re.compile(r'[u4e00-u9fa5]+')
    result = pat.findall(msg)
    print(result)
    for i in result:
        num += len(i)

    return num


with open('xdth.txt','r') as f:
    a = f.read()

    print(ret(a))