shell_objects.pyo: 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 CentOS possible default full paths are:

/usr/lib/python2.6/site-packages/windmill/bin/shell_objects.pyo - from package: python-windmill

You may install the required package with command yum install {package}

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