For those who might not know, Flycheck is a plugin which checks the syntax of the code you're writing on the fly, without forcing you to save the file. It does that by periodically saving the buffer to a temporary file, and running the syntax checker on that.
This way, you get instant feedback whenever you make a mistake, just like in an IDE, and (most importantly) if you're doing live development, with your program running in the background and reloading its files whenever it detects a change, it won't crash and burn if you make a small typo or syntax error.
The plugins I've looked into (Syntastic and python-mode) only run the syntax checker on save. Is there a better alternative?