code: def _expand_attrs(self, attrs):
      for attr in attrs:
          val = getattr(self, attr)
          if val is not None:
              if os.name in ("posix", "nt"):
                  val = os.path.expanduser(val)
              val = subst_vars(val, self.config_vars)
              setattr(self, attr, val)
  
imports: import sys
  import os
  import contextlib
  import sysconfig
  import itertools
  from distutils._log import log
  from ..core import Command
  from ..debug import DEBUG
  from ..sysconfig import get_config_vars
  from ..file_util import write_file
  from ..util import convert_path, subst_vars, change_root
  from ..util import get_platform
  from ..errors import DistutilsOptionError, DistutilsPlatformError
  from .None import _framework_compat
  from ..None import _collections
  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