relatedness.py: 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/lib/qiime/bin/relatedness.py - from package: qiime

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

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