- helloworld

- https://www.mchk.org.hk/english/list_register/list.php?type=L

- from page structure, get link:
  - https://www.mchk.org.hk/english/list_register/list.php?page=1&ipp=20&type=L

history:

- bf_helloworld_old.py
- bf_helloworld_1.py
- bf_helloworld_1-extract.py
- bf_helloworld.py

- https://realpython.com/python-mutable-vs-immutable-types/