pviews3: 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/pviews3 - from package: python3-pyramid

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

Error in other languages:
pviews3: bevel nie gevind nie
pviews3: comandă negăsită
pviews3: comando não encontrado
pviews3: commande introuvable
pviews3: command not found
pviews3: käsku ei ole
pviews3: không tìm thấy lệnh
pviews3: komanda nerasta
pviews3: Kommando nicht gefunden.
pviews3: kommandot finns inte
pviews3: komut yok
pviews3: nie znaleziono polecenia
pviews3: níor aimsíodh an t-ordú
pviews3: no se encontró la orden
pviews3: no s'ha trobat l'ordre
pviews3: opdracht niet gevonden
pviews3: parancs nem található
pviews3: perintah tidak ditemukan
pviews3: príkaz nenájdený
pviews3: příkaz nenalezen
pviews3: команда не найдена
pviews3: командата не е открита
pviews3: 命令找不到
pviews3: コマンドが見つかりません