Program producing some random output and errors in random intervals.

test.py

#!/usr/bin/env python3
# -*- coding: utf-8 -*-


import random
import sys
import time


for i in range(1000):
    time.sleep(random.betavariate(0.2, 1))

    if random.random() < 0.1:
        print("Error #{}".format(random.randint(1, 99)), file=sys.stderr)
    else:
        print(random.randrange(1000000))