presage_python_demo: 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 Debian possible default full paths are:

/usr/bin/presage_python_demo - from package: python-presage

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

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