class_docstr: Handles metadata supplied in configuration files.
class_docstr_tok: ["Handles","metadata","supplied","in","configuration","files","."]
docstr: Represents value as a module attribute.
  
  Examples:
      attr: package.attr
      attr: package.module.attr
  
  :param str value:
  :rtype: str
docstr_tok: ["Represents","value","as","a","module","attribute",".","Examples",":","attr",":","package.attr","attr",":","package.module.attr",":","param","str","value",":",":","rtype",":","str"]
code: def _parse_attr(self, value, package_dir, root_dir: _Path):
      """Represents value as a module attribute.
  
      Examples:
          attr: package.attr
          attr: package.module.attr
  
      :param str value:
      :rtype: str
      """
      attr_directive = "attr:"
      if not value.startswith(attr_directive):
          return value
  
      attr_desc = value.replace(attr_directive, "")
  
      # Make sure package_dir is populated correctly, so `attr:` directives can work
      package_dir.update(self.ensure_discovered.package_dir)
      return expand.read_attr(attr_desc, package_dir, root_dir)
  
imports: import contextlib
  import functools
  import os
  from collections import defaultdict
  from functools import partial
  from functools import wraps
  from typing import TYPE_CHECKING, Callable, Any, Dict, Generic, Iterable, List, Optional, Set, Tuple, TypeVar, Union
  from ..errors import FileError, OptionError
  from ..extern.packaging.markers import default_environment
  from ..extern.packaging.requirements import InvalidRequirement, Requirement
  from ..extern.packaging.specifiers import SpecifierSet
  from ..extern.packaging.version import InvalidVersion, Version
  from ..warnings import SetuptoolsDeprecationWarning
  from .None import expand
label_desc: Use image node_id 10 for calling the ConfigHandler obj's underlying member method code with example usage: obj._parse_attr(value, package_dir, root_dir) and returns: expand, value