python3m: 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/python3m - from package: python3-minimal

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

Error in other languages:
python3m: bevel nie gevind nie
python3m: comandă negăsită
python3m: comando não encontrado
python3m: commande introuvable
python3m: command not found
python3m: käsku ei ole
python3m: không tìm thấy lệnh
python3m: komanda nerasta
python3m: Kommando nicht gefunden.
python3m: kommandot finns inte
python3m: komut yok
python3m: nie znaleziono polecenia
python3m: níor aimsíodh an t-ordú
python3m: no se encontró la orden
python3m: no s'ha trobat l'ordre
python3m: opdracht niet gevonden
python3m: parancs nem található
python3m: perintah tidak ditemukan
python3m: príkaz nenájdený
python3m: příkaz nenalezen
python3m: команда не найдена
python3m: командата не е открита
python3m: 命令找不到
python3m: コマンドが見つかりません