我在写博客《Linux的1000个命令》的时候，相对二级标题进行一下排序，方便阅读和查找，于是就有了这个小程序。

#! /usr/bin/env python3import osimport subprocessclass BaseMethod:    @staticmethod    def run_cmd(cmd):        retcode, output = subprocess.getstatusoutput(cmd)        return retcode, output    @staticmethod    def write_file(filename, content):        with open(filename, 'w', encoding='UTF-8')as tf:            tf.write(content)    @staticmethod    def read_file(file_name, mode="r"):        if not os.path.exists(file_name):            raise IOError("No such file or directory: %s" % file_name)        with open(file_name, mode, encoding='UTF-8')as fp:            content = fp.read()        return contentf="linux.md"class SortMD:    def __init__(self, filename):        # self.filename = filename        self.content = BaseMethod.read_file(filename)        self.data = {}    def split_now(self):        sharp2 = self.content.split('##')        for i in sharp2:            if i.startswith('#'):                self.data['sharp1'] = i            else:                if 'sharp2' in self.data.keys():                    self.data['sharp2'].append('## '+i.strip('\n'))                else:                    self.data['sharp2'] = ['##' + i.strip('\n')]        print(self.data)        self.data['sharp2'].sort()        print(self.data)    def save2file(self, name):        s1 = self.data['sharp1']        s2 = "\n\n".join(self.data['sharp2'])        data = s1 + s2        print(data)        BaseMethod.write_file(name, data)def main():    md = SortMD(f)    md.split_now()    md.save2file("new.md")if __name__ == "__main__":    main()