errormaker.vimとQuickFixウインドウの自動開閉 ref: http://qiita.com/FGtatsuro/items/bc596674a5401259a249

python.vim

setlocal makeprg=/Users/tatsuro/python/pythonbrew/bin/flake8\ %
setlocal errorformat=%f:%l:%m

""" getqflist()でQuickFixのエラー件数が取得できる.
function! s:open_quickfix_window()
    silent make | redraw!
    if (len(getqflist()) == 0)
        cclose
    else
        copen
    endif
endfunction

if !exists("g:python_flyquickfixmake")
    let g:python_flyquickfixmake = 1
    au BufWritePost *.py call s:open_quickfix_window()
endif