How to correctly enable pylint with ALE in Vim?

Question

I want to set up python linting in Vim using the ALE Vim-package. So far it works well in Atom using the Atom-Plugin, but in Vim it somehow is not working. I installed

• pylint using pip3,
• Vim 8.1 and
• ALE using the Vundle Plugin-Manager.

In my .vimrc I set the

let g:ale_linters={
'python': ['pylint'],
.....+other languages....
}

option. Additionally I read the ALE docs and also tried setting the following:

let g:ale_python_executable='python3'
let g:ale_python_pylint_use_global=1

ALE gets installed correctly and works for Javascript, but for Python, there is just nothing happening. In case of incorrect code (missing ")") like:

print("Hi"

nothing is marked as error.

It would be great if someone knows how to set this up and can provide some help! Thanks.

Answer 1

I was able to get this working, with the following steps:

1. install pylint

   python3 -m pip install pylint

   At least for my setup there was a warning:

   Installing collected packages: pylint

   WARNING: The scripts epylint, pylint, pyreverse and symilar are installed in '/home/vagrant/.local/bin' which is not on PATH.

   so then:

2. Add pylint to $PATH

   export PATH="$HOME/.local/bin:$PATH"

   (this can be added to ~/.profile to be configured persistently)

   At you should be able to run pylint manually:

   $ cat syntaxerr.py
   print("hi
   $ pylint syntaxerr.py
   ************* Module syntaxerr
   syntaxerr.py:1:10: E0001: EOL while scanning string literal (, line 1) (syntax-error)
   

3. Install ALE

   git clone https://github.com/dense-analysis/ale.git ~/.vim/pack/git-plugins/start/ale

At this point the syntax check is working as long as syntax is enabled:

$ cat .vimrc
syntax on

If you'd like to configure g:ale_linters, note that you must escape the newline to create a multi-line dictionary:

let g:ale_linters={
\ 'python': ['pylint'],
\}

Finally, to see how ALE is currently configured, you can always run the following command:

:ALEInfo