如何使用Python3.5来解决cPickle的Python2.7错误？

Question

I need to use Python3.x in order to work around the following bug with cPickle . The task needs to be completed soon.

I'm running into the following error using cPickle with Python 2.7.10 . In fact, it's a bug which was only solved with Python3.x

http://bugs.python.org/issue11564

So, I installed Python3.5. Now, the script doesn't run, as I do not have modules installed for Python3, eg

     import matplotlib.pyplot as plt 
ImportError: No module named 'matplotlib

How should users begin downloading all the modules installed in Python 2.7 to Python 3.5?

Answer 1

pip freeze can do the work of mirroring package setups from one Python install to another.

Assuming pip is installed for both versions of Python (we'll name them pip2 and pip3 , you may need to use qualified paths to each depending on OS and configuration), you'd just do:

pip2 freeze > requirements.txt
pip3 install -r requirements.txt

That will install the same package and version for each package installed under the Py2 install in your Py3 install. See the pip freeze docs for switches to tweak the output. I believe you could also delete the ==xyz part of each requirement if you want the latest version instead of the same version.