How to "search" for a specific combination of bytes in PRNG?

Question

Python

There is a pseudo-random number generator - it displays (one byte at a time) a certain combination according to its algorithm:

bytes = ("%02x" % (algo))
sys.stdout.write(bytes)

Question: how to "search" for a specific combination of bytes?
For example, the output of the generator is a1b2c3d4e5f6, and you need to stop the program execution if exactly the given bytes d4e5 appear during the generation process ('d4', and immediately after it 'e5').
One byte at a time is clear:

if bytes == 'd4':
    exit(0)

But if the first value is correct, then what about checking the second (third, fourth, etc.) immediately after it?

Answer 1

# для длинного хвоста
tail = (None, None)
for r in 0xa1, 0xb2, 0xc3, 0xd4, 0xe5, 0xf6: # да, вот такой хреновый гпсч
    print("%02x" % r)
    tail = tail[1:] + (r,)
    if tail == (0xd4, 0xe5):
        break

# для короткого хвоста
t = None
for r in 0xa1, 0xb2, 0xc3, 0xd4, 0xe5, 0xf6:
    print("%02x" % r)
    if t == 0xd4 and r == 0xe5:
        break
    t = r

ps word bytes is already taken - read about it at your leisure .