code: def if_all_installed(self):
          
          count_inst = 0
          for inst in (self.dep_install + self.install):
              if (os.path.isfile(self.meta.pkg_path + inst[:-4]) and
                      "--download-only" not in self.flag):
                  count_inst += 1
          if (count_inst == len(self.dep_install + self.install) and
                  "--reinstall" not in self.flag):
              raise SystemExit()
docs: Check if all packages is already installed