PEP8

https://spoqa.github.io/2012/08/03/about-python-coding-convention.html

함수의 시작은 아래와 같이 대응하도록

– get/set

– add/remove

– create/destroy

– start/stop

– insert/delete

– increment/decrement

– old/new

– begin/end

– first/last

– up/down

– min/max

– next/previous

– open/close

– show/hide

– suspend/resume

– parent/child