code: def initialize_plugin(self):
          
          if self._patterns or self._packagetypes:
              logger.debug(
                  "Skipping initalization of Exclude Platform plugin. "
                  + "Already initialized"
              )
              return
  
          try:
              tags = self.configuration["blacklist"]["platforms"].split()
          except KeyError:
              logger.error(f"Plugin {self.name}: missing platforms= setting")
              return
  
          for platform in tags:
              lplatform = platform.lower()
  
              if lplatform in ("windows", "win"):
                  # PEP 425
                  # see also setuptools/package_index.py
                  self._patterns.extend([".win32", "-win32", "win_amd64", "win-amd64"])
                  # PEP 527
                  self._packagetypes.extend(["bdist_msi", "bdist_wininst"])
  
              elif lplatform in ("macos", "macosx"):
                  self._patterns.extend(["macosx_", "macosx-"])
                  self._packagetypes.extend(["bdist_dmg"])
  
              elif lplatform in ("freebsd"):
                  # concerns only very few files
                  self._patterns.extend([".freebsd", "-freebsd"])
  
              elif lplatform in ("linux"):
                  self._patterns.extend(
                      [
                          "linux-i686",  # PEP 425
                          "linux-x86_64",  # PEP 425
                          "linux_armv7l",  # https://github.com/pypa/warehouse/pull/2010
                          "linux_armv6l",  # https://github.com/pypa/warehouse/pull/2012
                          "manylinux1_",  # PEP 513
                          "manylinux2010_",  # PEP 571
                      ]
                  )
                  self._packagetypes.extend(["bdist_rpm"])
  
          logger.info(f"Initialized {self.name} plugin with {self._patterns!r}")
docs: Initialize the plugin reading patterns from the config.