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 protocol
parameter in pickle.dump
. Your resulting code will look like this.
pickle.dump(your_object, your_file, protocol=2)
There is no protocol
parameter 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
.