Good info and something tocheck on....only a state legislature is empowered to pass laws....a city council can only pass rules, ordinances, codes, etc. for their Muni corporation. Those are not (positive) laws and are unenforceable....it's the same as someone like IBM sending you a letter saying that you have to follow their dress code or rules of conduct. That city corporation has no authority over your affairs.
LOL. What do you think a code or ordinance is if it's not a law? Does your city have an ordinance regarding open container on public streets? If so, get yourself and beer and walk past a cop on the sidewalk. As he's toting you to jail, please tell him the city ordinance is "unenforceable" and then report back to me his response.