pydoc3.4: 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/pydoc3.4 - from package: python3.4

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

Error in other languages:
pydoc3.4: bevel nie gevind nie
pydoc3.4: comandă negăsită
pydoc3.4: comando não encontrado
pydoc3.4: commande introuvable
pydoc3.4: command not found
pydoc3.4: käsku ei ole
pydoc3.4: không tìm thấy lệnh
pydoc3.4: komanda nerasta
pydoc3.4: Kommando nicht gefunden.
pydoc3.4: kommandot finns inte
pydoc3.4: komut yok
pydoc3.4: nie znaleziono polecenia
pydoc3.4: níor aimsíodh an t-ordú
pydoc3.4: no se encontró la orden
pydoc3.4: no s'ha trobat l'ordre
pydoc3.4: opdracht niet gevonden
pydoc3.4: parancs nem található
pydoc3.4: perintah tidak ditemukan
pydoc3.4: príkaz nenájdený
pydoc3.4: příkaz nenalezen
pydoc3.4: команда не найдена
pydoc3.4: командата не е открита
pydoc3.4: 命令找不到
pydoc3.4: コマンドが見つかりません