How to let Vim work with pyenv?

Question

I've created some Python virtual environments:

hmanx ~ » pyenv virtualenvs
  3.7.4/envs/nn (created from /home/roach/.pyenv/versions/3.7.4)
  3.8.2/envs/py38 (created from /home/roach/.pyenv/versions/3.8.2)
  nn (created from /home/roach/.pyenv/versions/3.7.4)
  py38 (created from /home/roach/.pyenv/versions/3.8.2)
  vim-jupyter (created from /usr)

And I want to use the virtualenv nn, I have installed some packages, like numpy.

What I expected is command :py3 import numpy could work.

What I've tried:

1. use vim plugin: Plug 'lambdalisue/vim-pyenv', but after run PyenvActivate nn command :py3 import numpy get error: ModuleNotFoundError: No module named 'numpy.core._multiarray_umath'.
2. set let &pythonthreehome='/home/roach/.pyenv/versions/3.7.4/envs/nn/bin/', get error: ModuleNotFoundError: No module named 'numpy'
3. export PYTHONPATH="/home/roach/.pyenv/versions/nn/bin":$PYTHONPATH, then run vim get error same to method 1.

So, how to let vim use python in a virtual environment?

Or could use virtual python version when run

python3 << EOF

EOF

in a vim script.

Answer 1

Here are the commands I use to create a python 3.6.0 pyenv on a Mac using homebrew. Please note that I use neovim but the process to create a pyenv will not be much different for vim.

1. Install readline and xz along with pyenv and pyenv-virtualenv

   brew install pyenv pyenv-virtualenv readline xz
   

2. Install python 3.6.0

   CFLAGS="-I$(brew --prefix openssl)/include" \
   LDFLAGS="-L$(brew --prefix openssl)/lib" \
   pyenv install -v 3.6.0
   

3. Create the pyenv in your $HOME directory (~/.venv):

   ~/.pyenv/versions/3.6.0/bin/python3 -m venv ~/.venv
   ~/.venv/bin/python3 -m pip install --upgrade pip
   ~/.venv/bin/python3 -m pip install neovim pynvim
   

4. Set the g:python3_host_prog variable in your ~/.vimrc:

   let g:python3_host_prog=$HOME.'/.venv/bin/python3'
   

5. Check to make sure everything is correctly set up in neovim.

   :checkhealth
   

Answer 2

A method is decalare export PYTHON_CONFIGURE_OPTS='--enable-shared' before pyenv install a virtual env(thanks to @puremourning):

env PYTHON_CONFIGURE_OPTS="--enable-shared" pyenv install 3.8.2, then activate it before open file use vim.

But still have a question, as my system python version is 3.8.3, virtual version 3.8.2 works. But if I install a new virtual env 3.7.4, failed.