file1 = "stringbench_log_cpython3.2"
file2 = "stringbench_log_cpython3.3"

with open(file1, "r") as log_file1:
    lines1 = log_file1.readlines()

with open(file2, 'r') as log_file2:
    lines2 = log_file2.readlines()

def extract_lines(lines):
    data = {}
    for line in lines:
        if not line.startswith('=') and not line.startswith('N'):
            parts = line.split('\t')
            data[parts[-1].strip()] = tuple(parts[:-1])
    return data

data1 = extract_lines(lines1[6:])
data2 = extract_lines(lines2[6:])

for key, item in data1.items():
    unicode1_time = float(item[0])
    unicode2_time = float(data2[key][0])
    difference = ((unicode1_time - unicode2_time) / unicode2_time) * 100
    if difference < -20:
        print "- %s: %f%%" % (key, difference)