binCrcGen  = [1, 0, 0, 1]
s=0b1101010010111
binPayload = [int(d) for d in str(bin(s))[2:]]


while len(binCrcGen) <= len(binPayload) and binPayload:
    if binPayload[0] == binCrcGen[0]:
        del binPayload[0]
        for j in range(len(binCrcGen)-1):
            binPayload[j] ^= binCrcGen[j+1]
        print(binPayload, "binPayload")
    while binPayload and binPayload[0] == 0:
        del binPayload[0]
        print(binPayload, "binPayload")
        
str1 = ''.join(str(e) for e in binPayload)
ces = int(str1,2)
ct = format(ces, 'b').zfill(4)
print(ct)