Python script for generating (password) strings of specified length and character composition.

pacc.py

""" 
PACC.PY: Passwords, Accidentally

Python script for generating (password) strings of specified length and character composition. 

Author: rwev (https://github.com/rwev)

Built-in dependencies only. 

See usage: 
    >python pacc.py --help

To make a portable executable of the program to be used throughout your development system, run:
    >pip install pyinstaller
    >pyinstaller pacc.py -F 
and place the generated /dist/resurgence.exe in your system path.
"""

from __future__ import print_function

import re
import os, sys, subprocess
import time
from optparse import OptionParser

import string
import random

parser = OptionParser()

parser.add_option(
    '-l', '--length',
    dest = 'string_length',
    type = 'int',
    default = 12,
    help = "Desired length of string. (Defaults to 12)"
)

parser.add_option(
    '-s', '--specials',
    action = 'store_true',
    dest = 'use_special_characters',
    default = False,
    help = 'Include special characters. (Defaults to False)'
)

(options, args) = parser.parse_args(sys.argv)

char_choice_set = string.ascii_letters + string.digits
if (options.use_special_characters):
    char_choice_set += string.punctuation

def chooseRandomCharacters(choice_set_str, num_chars_int):
    '''Takes num_chars random characters from choice_set with the possibility of repetition.
    '''
    return ''.join(random.choice(choice_set_str) for _ in range(num_chars_int))

def doStringsShareCharacters(string_1, string_2):
    for c in string_1:
        if c in string_2:
            return True
    return False

requirements_fulfilled = False
while not requirements_fulfilled:
    random_string = chooseRandomCharacters(char_choice_set, options.string_length)

    requirements_fulfilled = True

    if not doStringsShareCharacters(random_string, string.lowercase):
        requirements_fulfilled = False
    if not doStringsShareCharacters(random_string, string.uppercase):
        requirements_fulfilled = False
    if not doStringsShareCharacters(random_string, string.digits):
        requirements_fulfilled = False
    if options.use_special_characters and not doStringsShareCharacters(random_string, string.punctuation):
        requirements_fulfilled = False

print(random_string)