bpython-urwid: 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/bpython-urwid - from package: bpython-urwid

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

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