old_contents: # This is just a kludge so that bdist_rpm doesn't guess wrong about the
  # distribution name and version, if the egg_info command is going to alter
  # them, another kludge to allow you to build old-style non-egg RPMs.
  
  from distutils.command.bdist_rpm import bdist_rpm as _bdist_rpm
  
  class bdist_rpm(_bdist_rpm):
  
      def initialize_options(self):
          _bdist_rpm.initialize_options(self)
          self.no_egg = None
  
      def run(self):
          self.run_command('egg_info')    # ensure distro name is up-to-date
          _bdist_rpm.run(self)
  
      def _make_spec_file(self):
          version = self.distribution.get_version()
          rpmversion = version.replace('-','_')
          spec = _bdist_rpm._make_spec_file(self)
          line23 = '%define version '+version
          line24 = '%define version '+rpmversion
          spec = [
              line.replace(
                  "Source0: %{name}-%{version}.tar",
                  "Source0: %{name}-%{unmangled_version}.tar"
              ).replace(
                  "setup.py install ",
                  "setup.py install --single-version-externally-managed "
              ).replace(
                  "%setup",
                  "%setup -n %{name}-%{unmangled_version}"
              ).replace(line23,line24)
              for line in spec
          ]
          spec.insert(spec.index(line24)+1, "%define unmangled_version "+version)
          return spec
  
new_contents: # This is just a kludge so that bdist_rpm doesn't guess wrong about the
  # distribution name and version, if the egg_info command is going to alter
  # them, another kludge to allow you to build old-style non-egg RPMs.
  
  from distutils.command.bdist_rpm import bdist_rpm as _bdist_rpm
  
  class bdist_rpm(_bdist_rpm):
  
      def initialize_options(self):
          _bdist_rpm.initialize_options(self)
          self.no_egg = None
  
      def run(self):
          # ensure distro name is up-to-date
          self.run_command('egg_info')
  
          _bdist_rpm.run(self)
  
      def _make_spec_file(self):
          version = self.distribution.get_version()
          rpmversion = version.replace('-','_')
          spec = _bdist_rpm._make_spec_file(self)
          line23 = '%define version ' + version
          line24 = '%define version ' + rpmversion
          spec = [
              line.replace(
                  "Source0: %{name}-%{version}.tar",
                  "Source0: %{name}-%{unmangled_version}.tar"
              ).replace(
                  "setup.py install ",
                  "setup.py install --single-version-externally-managed "
              ).replace(
                  "%setup",
                  "%setup -n %{name}-%{unmangled_version}"
              ).replace(line23, line24)
              for line in spec
          ]
          insert_loc = spec.index(line24) + 1
          unmangled_version = "%define unmangled_version " + version
          spec.insert(insert_loc, unmangled_version)
          return spec
  
subject: Adjust to match modern style conventions.