Performance options for sys.stdout.writelines

[Pedroski55]

These 2 php files are are < 8kb and they only have 5 lines which are not the same.
This takes zero.something seconds to complete. About as long as it takes to press enter.
Maybe buy a new computer? I recommend Ryzen R9 processors!

path1 = '/var/www/html/20BE1cw/20BE1sW3.html.php'
path2 = '/var/www/html/20BE2cw/20BE2sW3.html.php'

with open(path1) as f1, open(path2) as f2:
    lines1 = f1.readlines()
    lines2 = f2.readlines()

# do this or you will get and index error when you get to the end of the shorter file.
if len(lines1) == len(lines2):
    data1 = lines1
    data2 = lines2
elif len(lines1) > len(lines2):
    data1 = lines1
    data2 = lines2
else:
    data1 = lines2
    data2 = lines1

diff = []

for d in range(len(data1)):
    if not data1[d] == data2[d]:
        diff.append(data2[d])

Output:
>>> len(diff)
5