You asked
Is the yongnuo yn17mm f 1 7m good for street photography?
The Yongnuo YN17mm f/1.7 is a good street lens. It's a prime, so it's small and it stays quiet. On Micro Four Thirds it frames like a 34mm on full frame, a classic street view that takes in the scene without pulling you into it. Autofocus is included, and f/1.7 gives you useful depth of field for quick shooting.
For a compact street setup, I'd look at the Panasonic Lumix GM5, the OM System OM-5, or the Olympus PEN E-PL10. Each one is a small body, and that matters more than extra megapixels. If you want to know how I think about it, read Street, and remember to be open about what you're doing when you photograph people.
Written by Claude from this site's pages.