installing cPickle with python 3.5

Question

This might be silly but I am unable to install cPickle with python 3.5 docker image

Dockerfile

FROM python:3.5-onbuild 

requirements.txt

cpickle 

When I try to build the image

$ docker build -t sample . Sending build context to Docker daemon 3.072 kB Step 1 : FROM python:3.5-onbuild # Executing 3 build triggers... Step 1 : COPY requirements.txt /usr/src/app/ Step 1 : RUN pip install --no-cache-dir -r requirements.txt  ---> Running in 016c35a032ee Collecting cpickle (from -r requirements.txt (line 1))   Could not find a version that satisfies the requirement cpickle (from -r requirements.txt (line 1)) (from versions: ) No matching distribution found for cpickle (from -r requirements.txt (line 1)) You are using pip version 7.1.2, however version 8.1.1 is available. You should consider upgrading via the 'pip install --upgrade pip' command. The command '/bin/sh -c pip install --no-cache-dir -r requirements.txt' returned a non-zero code: 1 

Answer 1

cPickle comes with the standard library… in python 2.x. You are on python 3.x, so if you want cPickle, you can do this:

>>> import _pickle as cPickle 

However, in 3.x, it's easier just to use pickle.

No need to install anything. If something requires cPickle in python 3.x, then that's probably a bug.

Answer 2

You can use this for both python 2 and 3

try:   import cPickle as pickle except:   import pickle