Random number generator that uses /dev/random as entropy source. Written as part of an experiment on the potential influences of the mind on the randomness of an event: a coin toss in this case.

main.py

#!/usr/bin/env python3       
import random
import matplotlib as plt
import time
import os
import struct

_random_source = open("/dev/random", "rb")

def random_bytes(len):
    return _random_source.read(len)

def unpack_uint32(bytes):
    tup = struct.unpack("I", bytes)
    return tup[0]

UINT32_MAX = 0xffffffff
def randint(low, high):
    """
    Return a random integer in the range [low, high], including
    both endpoints.
    """
    n = (high - low) + 1
    assert n >= 1
    scale_factor = n / float(UINT32_MAX + 1)
    random_uint32 = unpack_uint32(random_bytes(4))
    result = int(scale_factor * random_uint32) + low
    return result

def randint_gen(low, high, count):
    """
    Generator that yields random integers in the range [low, high],
    including both endpoints.
    """
    n = (high - low) + 1
    assert n >= 1
    scale_factor = n / float(UINT32_MAX + 1)
    for _ in range(count):
        random_uint32 = unpack_uint32(random_bytes(4))
        result = int(scale_factor * random_uint32) + low
        yield result

def stopwatch(seconds):
    start = time.time()
    time.clock()    
    elapsed = 0
    while elapsed < seconds:
        elapsed = time.time() - start
        print("loop cycle time: %f, seconds count: %02d" % (time.clock() , elapsed))
        time.sleep(1)

if __name__ == "__main__":
    # roll 2 dice individually with randint()
    result = [randint(0, 1) for _ in range(2)]
    print(result)

    # roll 2 dice more efficiently with randint_gen()
    print(list(randint_gen(0, 1, 2)))