nosetests: 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/bin/nosetests - from package: python-nose

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

On Debian possible default full paths are:

/usr/bin/nosetests - from package: python-nose

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

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