exercicio_maciel.py

fhand = open('mbox-short.txt')
count = 0
total = 0 # acumuladora/totalizadora
for line in fhand:
    line = line.rstrip()
    if line.startswith('X-DSPAM-Confidence: '):
        count = count + 1
        limit = line.find(':')
        line = float(line[limit+1:])
        total = total + line # cálculo, o valor atual mais o valor de cada linha
        print (line)

print ('Count:',count)
print ('Sum:',total)
print ('Average:',(total / count))