class_docstr: Base selector implementation.
class_docstr_tok: ["Base","selector","implementation","."]
code: def __init__(self):
      # this maps file descriptors to keys
      self._fd_to_key = {}
      # read-only mapping returned by get_map()
      self._map = _SelectorMapping(self)
  
imports: from abc import ABCMeta, abstractmethod
  from collections import namedtuple
  from collections.abc import Mapping
  import math
  import select
  import sys
label_desc: Use image node_id 1 to create a new _BaseSelectorImpl object from inherited base classes: BaseSelector with example: obj = _BaseSelectorImpl()