VIM: Use python3 interpreter in python-mode

Question

I have recently switched to vim and configured it for Python-programming using this tutorial. Before, I have made sure that vim supports python3 (vim --version shows +python/dyn and +python3/dyn) using this article.

But when executing a file from python-mode, still the python2.7 interpreter is chosen.

How can I configure vim (or the python-mode) to run files on the python3 interpreter?

My OS is Ubuntu 14.04 x64.

Thanks in advance!

Answer 1

Try adding this to your .vimrc file

let g:pymode_python = 'python3'

I found this in the help docs. In vim type:

:help python-mode

By default, vim is not compiled with python3 support, so when I tried this, I got all kinds of errors... Which tells me it's trying to use python3. But if your vim --version output shows +python3 you should be good.

EDIT: By default, Ubuntu 14.04 doesn't come with +python3 support. And due to limitations, you can't have both python2 and python3 support.

So, you have to compile vim with python3 support.

These are the steps that worked for me: From a linux command line:

Install packages

sudo apt-get install checkinstall mercurial python-dev python3-dev ruby ruby-dev libx11-dev libxt-dev libgtk2.0-dev libncurses5 ncurses-dev

Grab the latest version of vim

hg clone https://vim.googlecode.com/hg/ vim

Configure it

cd vim
./configure \
--enable-perlinterp \
--enable-python3interp \
--enable-rubyinterp \
--enable-cscope \
--enable-gui=auto \
--enable-gtk2-check \
--enable-gnome-check \
--with-features=huge \
--enable-multibyte \
--with-x \
--with-compiledby="xorpd" \
--with-python3-config-dir=/usr/lib/python3.4/config-3.4m-x86_64-linux-gnu \
--prefix=/opt/vim74

Compile it

make

Test it

make test

Install it

sudo checkinstall

Link the package

sudo ln -s /opt/vim74/bin/vim /usr/bin/vim-py3

Now, you have both versions of vim

To use normal vim (python2) type vim file.py

To use vim with python3 support type vim-py3 file.py

If you just want the python3 version, then you only need to link it to the new vim

ln -s /opt/vim74/bin/vim /usr/local/bin/vim

And if you want to switch back to the python2 version, remove the link

rm /usr/local/bin/vim