如何使用现有字典填充货架

Question

可以说我有一个很大的,100兆字节的字典,我想把它放到磁盘上.我正在使用pypar来利用MPI生成主列表的清理位.实现这一目标的最佳方法是什么？例:

# much earlier
masterDict = shelve.open( 'aShelveFile' )
# .. . . . . 
# then we work out which parts of masterDict to keep
# and we put into aCleanDict
# then use mpi pypar to send the cleaned bits to the master rank
if pypar.rank() == 0:
  tempdict = {}
  for p in range(1,pypar.size()):
    tempdict.append(pypar.receive(p))
  for l1 in tempdict:
    for l2 in l1:
      realDict.append(l2)
  for p in range(1,pypar.size()):
    pypar.send(realDict,p)

  # now realDict has all the cleaned bits
  # which we send to the other hosts
else:
  pypar.send(aCleanDict, 0 )
  aCleanDict = pypar.receive( 0 )

# now to replace masterDict  with aCleanDict
# note: cannot send shelve dictonaries using pypar

# insert stackover flow code here.

Answer 1

在这里你搁置一个简单的字典,并通过密钥访问它myDict:

import shelve
myDict = {"a" : 1, "b" : 2}
myShelvedDict = shelve.open("my_shelved_dictionary.db")
myShelvedDict["myDict"] = myDict

请注意,字典的内容必须是可选择的,就像要搁置的任何内容一样.

如果你想在货架上复制字典的结构,即没有myDict键但字典的键直接作为货架的键,你可以使用updateshelve 的方法:

myShelvedDict.update(myDict)

所述shelve接口具有与一个大的重叠dict之一.