Possible to run Python 2.7 and Python 3 in same notebook?

Question

This question is similar to this question. I have to support Python 2.7 and 3.

I have some code that is written in python 3. This works great on my python 3 install (anaconda for win7 + jupyer-notebook). I need to unit test my code under a python 2.7 environment.

Is there an easy way to setup a 2.7 environment on my anaconda setup without clobbering my working install? It would be really cool to be able to run python 2 under a 3 notebook using a magic command!

you can have python 2 and 3 installed at the same time, their packages are managed separately — AllenMoh, Aug 23 '17 at 19:00
You can definitely have both python 2 and python 3 environments set up under Anaconda, but a _notebook_ (Jupyter) only currently attaches to a single kernel, and thus can only run a single version at a time. If you can edit the Python 2 code, use `six` as suggested in the question you linked to so that your code runs in a single Py 2 or Py 3 environment. What are you actually trying to accomplish? Please give example. — scnerd, Aug 23 '17 at 19:04
thanks for the tips! I maintain this package: https://github.com/twdb/sonde3 I have an example notebook, and unit tests (nosetests). My unit tests work fine in python3, but I need to run this in a 2.7 environment to bug fix and run the tests. — name goes here, Aug 23 '17 at 19:26

score 1 · Answer 1 · answered Mar 25 '18 at 18:50

Step1: Download anaconda for both the version

Step 2: open .bashrc

Step 3: add the path to new anaconda you have installed for eg:

export PATH="/home/paras/anaconda3/bin:$PATH"

Step 4: Now there will be 2 export path one for python 2 and one for python 3.

Comment the one which you don't want

score 0 · Answer 2 · answered Aug 23 '17 at 19:07

Yes, you can have python 2.7 and 3 on the same system. Use the shebang on the top of your script to make the distinction between the 2 as necessary. These discussions should also address some of your concerns -

How to install both Python 2.x and Python 3.x in Windows 7

How do I run python 2 and 3 in windows 7?.

score 0 · Answer 3 · answered Aug 25 '17 at 12:14

What you can do is creating 2 conda virtual environment and choose the kernel you want your jupyter notebook to run on. You should install nb_conda_kernels so that your environments are automatically recognized as different kernels. Follow this procedure (after having installed anaconda/miniconda):

Outside any environment, install nb_conda_kernels: conda install -c conda-forge nb_conda_kernels
Outside any environment, install jupyter: pip install jupyter
Create a virtual environment and activate it
In the environment, install jupyter: pip install jupyter
Inside any environment, run jupyter notebook
Choose the environment by clicking on the kernels tab

https://github.com/Anaconda-Platform/nb_conda_kernels

thewaywewere · Answer 4 · 2017-08-26T22:57:01.253

The following is the steps to create a Anaconda virtual environment to ease your testing.

Open a Anaconda Prompt window.
Type conda create -n py27 python=2.7 anaconda to create a new virtual environment named py27. You can create any new virtual environment with different version of Python, e.g. Python=3.6, for testing purpose.
Launch the root Jupyter Notebook to start Jupyter server.
Open your Python 3 notebook with the codes to be tested, from your Jupyter dashboard browser.
From menu bar, → Kernel → Change kernel → {select target env} for your code testing

Hope this help.

Possible to run Python 2.7 and Python 3 in same notebook?

4 Answers4