class_docstr: The main 'connection' object for PickleShare database 
class_docstr_tok: ["The","main","'connection","'","object","for","PickleShare","database"]
docstr: db['key'] reading 
docstr_tok: ["db","[","'key","'","]","reading"]
code: def __getitem__(self, key):
      """db['key'] reading"""
      fil = self.root / key
      try:
          mtime = fil.stat()[stat.ST_MTIME]
      except OSError:
          raise KeyError(key)
  
      if fil in self.cache and mtime == self.cache[fil][1]:
          return self.cache[fil][0]
      try:
          # The cached item has expired, need to read
          with fil.open("rb") as f:
              obj = pickle.loads(f.read())
      except:
          raise KeyError(key)
  
      self.cache[fil] = (obj, mtime)
      return obj
  
imports: from __future__ import print_function
  import os, stat, time
  import errno
  import sys
label_desc: Use image node_id 2 for calling the PickleShareDB obj's underlying member method code with example usage: obj.__getitem__(key) and returns: obj, self