No person, other than a contractor in the performance of public work pursuant to a contract with the City, and other than the Director of Public Service or his authorized subordinates, shall make any opening, excavation or cut in, or remove any pavement, sod or other surface material from any street or other thoroughfare, or from any park or other public grounds, unless such person shall have applied for and received a permit from the Director of Public Safety. However, the provisions of this and Section 901.02 do not apply to openings or excavations made for the setting of poles or posts.