pylint-gui: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/bin/pylint-gui - from package: pylint-gui

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/pylint-gui - from package: pylint

You may install the required package with command apt-get install {package}

Error in other languages:
pylint-gui: bevel nie gevind nie
pylint-gui: comandă negăsită
pylint-gui: comando não encontrado
pylint-gui: commande introuvable
pylint-gui: command not found
pylint-gui: käsku ei ole
pylint-gui: không tìm thấy lệnh
pylint-gui: komanda nerasta
pylint-gui: Kommando nicht gefunden.
pylint-gui: kommandot finns inte
pylint-gui: komut yok
pylint-gui: nie znaleziono polecenia
pylint-gui: níor aimsíodh an t-ordú
pylint-gui: no se encontró la orden
pylint-gui: no s'ha trobat l'ordre
pylint-gui: opdracht niet gevonden
pylint-gui: parancs nem található
pylint-gui: perintah tidak ditemukan
pylint-gui: príkaz nenájdený
pylint-gui: příkaz nenalezen
pylint-gui: команда не найдена
pylint-gui: командата не е открита
pylint-gui: 命令找不到
pylint-gui: コマンドが見つかりません