python通过txt文本中提取目录（无论文章是否将目录提取到文章开头）

以参考文献为截至

import re

# 分析header
def main_read_txt():
    url = "txt\zhengwen.txt"
    with open(url, "r", encoding='utf-8') as f:
        count = f.readlines()
        for line in count:
            if line.find('参考文献(References)') < 0:
                line = line.strip('n')  # 去掉列表中每一个元素的换行符
                if len(line) >= 3 and line != 'x0c':
                    # print(line[0], line[1], line[2])
                    if re.match(r'd', line):
                        print(line)
                    elif re.match(r'(d', line):
                        print(line)
            else:
                break

if __name__ == '__main__':
    main_read_txt()