I do this too but I really don't like the noticeable lag that gets introduced as flycheck shells out to python and parses my file every time I change something.
Are you sure the lag is because of Python? I'd check flymake options first, it may wait for some time after you stop typing and only then start linting. This delay is a trade-off: too short and you're going to have currently edited line marked with red most of the time, too long and you need to wait to see if everything is alright.