ValueError: unsupported pickle protocol: 3, python2 pickle can not load the file dumped by python 3 pickle?
You should write the pickled data with a lower protocol number in Python 3. Python 3 introduced a new protocol with the number 3 (and uses it as default), so switch back to a value of 2 which can be read by Python 2.
Check the protocolparameter in pickle.dump. Your resulting code will look like this.
pickle.dump(your_object, your_file, protocol=2)There is no protocolparameter in pickle.load because pickle can determine the protocol from the file.
Pickle uses different protocols to convert your data to a binary stream.
In python 2 there are 3 different protocols (
0,1,2) and the default is0.In python 3 there are 5 different protocols (
0,1,2,3,4) and the default is3.
You must specify in python 3 a protocol lower than 3 in order to be able to load the data in python 2. You can specify the protocol parameter when invoking pickle.dump.