Galois LSFR implementation for python

lsfr.py

""" simple LFSR generator

Uses galois algorithmn to return next bit of LFSR.
To initialize the generator pass the seed value (one
value that the generator will generate, != 0) and 
the used polynom.
Observe that for a n bit polynom, x^n has to be in
the polynom, which should be the case anyhow therefore e.g.:

  x^4 + x^3 + 1 = 0b1100
  
>>> import itertools
>>> x = lsfr(0b0110, 0b1100)
>>> list(itertools.islice(x, 16))
[0, 1, 1, 0, 1, 0, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0]
"""
def lsfr(seed, polynom):
    data = seed
    poly = polynom

    while 1:
        lsb = data & 1
        data = data >> 1
        if lsb != 0:
            data = data ^ poly
            yield 1
        else:
            yield 0

""" polynoms for maximum length sequences """
maxLenPoly = {
    2  : 0b11,
    3  : 0b110,
    4  : 0b1100,
    5  : 0b10100,
    6  : 0b110000,
    7  : 0b1100000,
    8  : 0b10111000,
    9  : 0b100010000,
    10 : 0b1001000000,
    11 : 0b10100000000,
    12 : 0b111000001000,
    13 : 0b1110010000000,
    14 : 0b11100000000010,
    15 : 0b110000000000000,
    16 : 0b1011010000000000,
    17 : 0b10010000000000000,
    18 : 0b100000010000000000,
    19 : 0b1110010000000000000,
}