python 3中的pickle和_pickle有什么区别？

I am new in python and want implement fast object serialization. I was trying to use json, but it was too slow, also was trying to use marshall module, but the size of the objects serialized by marshall 6-7 times more than pickle, so i decided to use pickle in my project. I read about cPickle module, read that it quite fast, but there is no such module in python 3 and docs says that module named _pickle is written in C. So in my projects i use obje