其中：pattern = re.compile(r’^.["“subject”"] [([^[])].*’)
为修改的正则匹配部分

python正则提取txt文本 - z珠穆朗玛鑫 - 博客园 (cnblogs.com)
import re
import pandas as pd
with open("C:/data1.txt", 'r', encoding='UTF-8') as f:
    data = f.readlines()
    f.close()
tol = []
for line in data:
##s = re.findall('[\u4e00-\u9fa5]', data) print(s)
    pattern = re.compile(r'^.*\[\"\"subject\"\"\] \[([^\[]*)\].*')
    string = str(line)
    url = re.findall(pattern,string)
    if (url is not None ) and (url != '[]'):
        tol.append(url)
print(tol)
pd.DataFrame(tol).to_csv('C:/tol2.csv')
##f1 = open("url.txt", "a+", encoding='utf-8')
##for urls in url:
##    f1.write(urls + '\n')
##f1.close()
##reg = re.compile(r'^.*\[\"\"subject\"\"\] \[(.*)\]')
##msg = '""i;octet""  [""subject""] [""小木虫""] ,accounts :in_main [""2012207469@tju.edu.c'
##mtch = reg.match(msg)
##print(mtch.group(1))

参考：https://www.cnblogs.com/xinxin999/p/13413231.html