passCredits = None
deferCredits = None
failCredits = None
something = 1


def repeat():
    getPassCredits()
    getDeferCredits()
    getFailCredits()
    totalCheck()

def getPassCredits():
    global passCredits
    passCredits = None
    while passCredits is None:
            passValue = input( "Please enter your pass mark: \n" )
            try:
                passCredits = int(passValue)
            except ValueError:
                print ('integers required \n' )

def getDeferCredits():
    global deferCredits
    deferCredits = None
    while deferCredits is None:
            deferValue = input( "Please enter your defer mark: " )
            try:
                deferCredits = int(deferValue)
            except ValueError:
                print ( "Integers required " )

def getFailCredits():
    global failCredits
    failCredits = None
    while failCredits is None:

            failValue = input( "Please enter your fail mark: " )
            try:
                failCredits = int(failValue)
            except ValueError:
                print ( " Integers required " )

def totalCheck():

    totalCredits = passCredits + deferCredits + failCredits
    if totalCredits != 120:
        print ( "Total Incorrect" )

    if passCredits % 20 != 0 or deferCredits % 20 != 0 or failCredits % 20 != 0:
        print ( "Range error" )
        repeat()

def display():
    if passCredits == 120:
        print ("Progress")
    elif passCredits == 100:
        print ("Progress - module trailer")
    elif failCredits>=80:
        print("Exclude")
    else:
        print("Do not progress - module retriever")

def test():
    repeat()
    display()

while something == 1:
    print (" Welcome to the progress checker pogU\n ")
    test()
    something = int(input("Press 1 to continue, or 0 to quit"))