Syntax Error: Invalid syntax

I'm writing a maths quiz and I'm trying to calculate an average of a students last score yet I am getting a syntax error on the last line:

    if type_of_sort == 3:
        with open (filename,'r') as r:
            def score(line):
                returnint(line.split(':')[1])
            average = (sum(map(line)/len(score))
            print(name, average)

Even when I removed the last line it would come up with a syntax error even if it wasn't there.The error looks like this:

Syntax Error: Invalid syntax (<module 1>, line 134)