TR;DL

1. Simply hack way.

python -m pip install gnureadline

2. Correct way(require python reinstall)

sudo apt install libreadline-dev
sudo apt install libbz2-dev
sudo apt install libsqlite3-dev
# Python reinstall
pyenv uninstall 3.8.8
pyenv install 3.8.8

Description

If python binary doesn't have the "readline" library, key codes like "^[[A" show in the command line; It might be probably seen when you are using 'pyenv'. We can check whether we face this problem by warning logs while installing.

In my case, I already installed libreadline and there is no warning log on readline. But, two warning logs still exist. So, I will solve these problems.

apt install libreadline-dev

apt install libbz2-dev

apt install libsqlite3-dev

And now that, there is no warning log.