def getrandbits(self, k):
        if k <= 0:
            raise ValueError('number of bits must be greater than zero')
        if k != int(k):
            raise TypeError('number of bits should be an integer')
        bytes = (k + 7) // 8                    # bits / 8 and rounded up
        x = long(_hexlify(_urandom(bytes)), 16)
        return x >> (bytes * 8 - k)             # trim excess bits
getrandbits(k) -> x.  Generates a long int with k random bits.
dataset/ETHPy150Open babble/babble/include/jython/Lib/random.py/SystemRandom.getrandbits