An example of a badly implemented random numerical ID generator based on ord() and os.urandom()

badexample.py

#!/usr/bin/env python3

"""
This code snippet is a deliberate bad implementation of a random numerical ID generator based on ord()
This will generate 150000 random 18-digit IDs and then show the frequency of each digit in the IDs.
You should see more 1s and 2s than other digits.

ord(os.urandom(1)) will return a random number up to 255. If you generate multiple values and concatenate them,
you will get a random code/ID up to the length you want, however, because ord is returning an int which is <255,
you will statistically get more 1s and 2s in your ID.
"""

import pprint
import os

def random_id(length):
	output = ""
	while len(output) < length:
		output += str(ord(os.urandom(1)))
	return output[:length]

def main():
	print("Example ID:", random_id(18), "\n")

	print("Generating a frequency table of each digit from 150000 randomly generated IDs using the above function\n")
	ftable = {}
	for x in range(1, 150000):
		gen = random_id(18)
		ints = list(gen)
		for i in ints:
			try:
				ftable[i] += 1
			except:
				ftable[i] = 1

	pp = pprint.PrettyPrinter(indent=4)
	pp.pprint(ftable)

	print("\nThe most common digits should be 1 and 2 due to this flaw in the implementation. Don't use this function for generating random IDs.")

if __name__ == "__main__":
	main()