with open('input.csv', 'rb') as infile:
    with open('output.csv', 'wb') as outfile:
        incsv = csv.reader(infile, delimiter=',', quotechar='"')
outcsv = csv.writer(outfile, delimiter=',', quotechar='"')
incsv.read()
for line in incsv:
    if line[3] != '':
        outcsv.write(ProcessLine(line))
TypeError: expected a character buffer object