How do I switch back to python2 after Anaconda set python3 as the default?

I went through the installation in a VM, and the following happend.

1. The installer asks for an install location. Default is /home/myuser/anaconda3.

2. At the end you'll be asked

   Python 3.5.1 :: Continuum Analytics, Inc.
   creating default environment...
   installation finished.
   Do you wish the installer to prepend the Anaconda3 install location
   to PATH in your /home/myuser/.bashrc ? [yes|no]
   [no] >>> yes
   
   Prepending PATH=/home/myuser/anaconda3/bin to PATH in /home/myuser/.bashrc
   A backup will be made to: /home/myuser/.bashrc-anaconda3.bak
   

To restore the old behavior, go to your home directory and do

mv .bashrc-anaconda3.bak .bashrc

then start a new shell.

As you suggest, you could alias python=python2, but I find that a bit weird. I would

1. Restore the original .bashrc
2. Create (if it does not exist) ~/bin
3. Link ln -s ~/anaconda3/bin/python3 ~/bin/python3
4. [Prepend $HOME/bin to $PATH](Should already be set by default by ~/.profile)
5. Relogin.

That way, calling python3 will start the one from Anaconda.

---

An important point is, that the original /usr/bin/python is still there, and still points to python2.7. The ramifications of having python->python3 in your path depend on how a specific script is called.

If the shebang #!/usr/bin/python is used, like it probably is in all executables that ship with Ubuntu, nothing will change. On the other hand, for better portability #!/usr/bin/env python is sometimes used, which will now cause python3.5 to be called.

Good answer here: https://stackoverflow.com/questions/24405561/how-to-install-2-anacondas-python-2-7-and-3-4-on-mac-os-10-9

conda create -n python2 python=2.7 anaconda

then, to switch:

source activate python2

In case anyone is looking to change their python default version back to 2.7 after messing it up(by changing default one to: anaconda or python 3) and ending up with non-functional software, just follow this link: Link with instructions to change default python version.