__init__.py 文件源码

def getrandbytes(rng, count):
    """return byte-string containing *count* number of randomly generated bytes, using specified rng"""
    # NOTE: would be nice if this was present in stdlib Random class

    ###just in case rng provides this...
    ##meth = getattr(rng, "getrandbytes", None)
    ##if meth:
    ##    return meth(count)

    if not count:
        return _BEMPTY
    def helper():
        # XXX: break into chunks for large number of bits?
        value = rng.getrandbits(count<<3)
        i = 0
        while i < count:
            yield value & 0xff
            value >>= 3
            i += 1
    return join_byte_values(helper())