# convert a sequence of bits (0 and 1) to an integer
def bin2int( a ):
    n = len(a)
    b = 0
    for i in range(n):
        # coefficients must be either 0 or 1
        assert a[i] == 0 or  a[i] == 1
        b += a[i] * 2**(n-i-1)
    return b

# an 8 bit sequence
a = [0,1,0,1,0,1,1,1]
print( bin2int(a) )