When cites pass laws they are called ordinances. Those ordinances are then usually collected into what is called a code. So the same law will have both an ordinance number (reflecting when it was passed), and a section number (reflecting where it can be found in the code). Recently passed ordinances might not be in the latest code. If you want to find the city law on a particular topic, it would be best to start by looking at the city code, and then seeing if there are any recent ordinances (that haven't been added to the code yet) that would impact your topic. However, if you want to find recently enacted laws, then it would make sense to start by looking at the ordinances.
The city code will usually provide the ordinance number, so from the code you can getting the original ordinance number. If you have an ordinance number, and want to find out where in the code it is, you can look at a table, which provides the current code section of an ordinance. (For the Tucson City Code, this table is called the Code Comparative Table).
Tucson (Arizona) Code: (Official) Cincinnati, Ohio: American Legal Publishing Corporation — Available online through the Tucson City Clerk's Office. Codification of laws by topic, then by title and section number. Topics include animals, building and construction codes, business licenses, cable and telecommunications, crimes, elections, occupation and privilege taxes, procurement, and traffic. Contains cross-references to state law and some annotations to case law. Available in Law Reserve.
Tucson (Arizona) Land Use Code: (Official) Tucson: City Planning Department — Available online through the Tucson City Planning and Development Services Department. Codification (1995) of land use technical regulations that cover zones, land development, subdivisions, and city zoning administration and procedures. Available in Law Reserve.
Code of the City of Phoenix (Arizona): (Official) Seattle, Washington: Code Publishing Company. Available online through the City of Phoenix. Codification of city laws, Charter, and ordinances including zoning. Arranged by Chapter-Section. Topics include administration, animals, building and construction, licenses, franchises, traffic, morals and conduct, parks, water, and zoning. Current through July 2016. Available in Law Reserve.
Zoning Ordinance of the City of Phoenix (Arizona): (Official) Seattle, Washington: Code Publishing Company. Available online through the City of Phoenix. Ordinances concerning zoning information including planning documents, zoning districts, fee schedules, development standards, enforcement. Current through June 2016. Available in Law Storage.
Maricopa County's Superior Court Law Library Resource Center offers a host of links to other city codes in Arizona.