pycorrfit: 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/pycorrfit - from package: pycorrfit

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

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