drpython: 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/drpython - from package: drpython

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

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