有人能帮我看下能跑但不优雅的python代码吗？包括测试代码与换行只有70行

Question

main.py

import os
import time
from zhihu_oauth import ZhihuClient
import html2text

_h = html2text.HTML2Text()

layout_format = {}

for filename in os.listdir('mod'):
    if filename.endswith('py'):
        exec(open(os.path.join('mod', filename)).read())

print(layout_format)

def format_date(unix_timestamp_str):
    return time.strftime("%Y-%m-%d %H:%M:%S", time.localtime(int(unix_timestamp_str)))

class ZhihuParser:
    def __init__(self, answer, layout='md'):
        self.layout = layout
        self.title = answer.question.title
        self.author = answer.author.name
        self.created_time = format_date(answer.created_time)
        self.updated_time = format_date(answer.updated_time)
        self.voteup_count = answer.voteup_count
        self.thanks_count = answer.thanks_count
        self.content = answer.content
        self.content = self.__parser()

    def __parser(self):
        return _h.handle(self.content)

    def __str__(self):
        return layout_format.get(self.layout)(self)

    def __getitem__(self, key):
        return eval('self.' + key)


if __name__ == "__main__":
    TOKEN_FILE = 'token.pkl'
    client = ZhihuClient()
    if os.path.isfile(TOKEN_FILE):
        client.load_token(TOKEN_FILE)
    else:
        client.login_in_terminal()
        client.save_token(TOKEN_FILE)
    print(ZhihuParser(client.answer(128260462)))
    exit()

mod/md.py

markdown_template = """# %(title)s
Author: %(author)s
Create Date: %(created_time)s
Last Update: %(updated_time)s

%(content)s
"""

def markdown(self):
    return markdown_template % self

layout_format['md'] = markdown

其中，

def __getitem__(self, key):
    return eval('self.' + key)

这段有更好的写法吗？

以及我想让用户把自己写的mod文件放到mod文件夹下程序自动挂载，实现代码为：

layout_format = {}

for filename in os.listdir('mod'):
    if filename.endswith('py'):
        exec(open(os.path.join('mod', filename)).read())

配合插件中的

layout_format['mod_name'] = mod_function

这样写有啥优化改进的地方吗？欢迎提建议