code: def _expand_attrs(self, attrs):
      for attr in attrs:
          val = getattr(self, attr)
          if val is not None:
              if os.name == "posix" or os.name == "nt":
                  val = os.path.expanduser(val)
              val = subst_vars(val, self.config_vars)
              setattr(self, attr, val)
  
imports: import sys
  import sysconfig
  import os
  import re
  from distutils import log
  from distutils.core import Command
  from distutils.debug import DEBUG
  from distutils.sysconfig import get_config_vars
  from distutils.errors import DistutilsPlatformError
  from distutils.file_util import write_file
  from distutils.util import convert_path, subst_vars, change_root
  from distutils.util import get_platform
  from distutils.errors import DistutilsOptionError
  from site import USER_BASE
  from site import USER_SITE
label_desc: Use image node_id 7 for calling the install obj's underlying member method code with example usage: obj._expand_attrs(attrs) without return types