dh_pypy: 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/dh_pypy - from package: dh-python

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

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