json seralization is more slower than cpickle

http://oldj.net/article/python-pickle/
i like use jsonpy than py2.6 embedded json lib,beacause it is more friendly for unicode
reference http://oldj.net/article/python-pickle/
some write style i record here:
import jsonpy
import os.path
import cPickle as pickle
import time
if os.path.exists("cache.pickle"):
it=time.time()
cache= pickle.load(open("cache.pickle", "rb"))
print "cost time:%ss"%(time.time()-it)
print "直接从cache.pickle载入"
print len(cache)
if os.path.exists("cache.txt") and (not os.path.exists("cache.pickle")):
print "从cache.txt载入"
cc=0
itit=time.time()
for line in open("cache.txt","r").readlines():
cc+=1
print cc
k,v=line.strip().split("||||||")
#print type(jsonpy.read(v))
cache[k]=jsonpy.read(v)
print "载入缓存成功"
print "cost time:%ss"%(time.time()-itit)
print len(cache)
from lib import filehelper
if filehelper.hasfile("cache.pickle"):
filehlper.delfile("cache.pickle")
print "删除先前的cache.pickle"
pickle.dump(cache, open("cache.pickle", "wb"), True)
print "导出成cache.pickle"