Hi, I have created a python script for creating strong passwords for singing a website. You can use it for creating a strong password easily. It is written by Mustafa Sarialp and its licence Public Domain.

create_password.py

#!/usr/bin/env python3
# ===============================================================================================================================
# Name        : create_password.py
# Author      : Mustafa Sarialp
# Version     : 1.0.2
# Copyright   : Public Domain
# Description : A python 3 script which creates strong passwords ( 12 character long) to use like singup... You can use it freely. 
# ================================================================================================================================

import random
def create_password():
    password = []
    new_password = ''
    letters = 'abcdefghijklmnopqrstuvwxyz'
    characters = '!+%&/{([)]=}?*'
    for i in range(12):
        letter = random.choice(letters)
        character = random.choice(characters)
        number = random.randrange(0, 10, 1)
        if i % 3 == 0:
            if i / 3 > 2:
                password.append(letter.capitalize())
            else:
                password.append(letter)
        elif i % 2 == 0:
            password.append(character)
        else:
            password.append(str(number))
    random.shuffle(password)
    new_password += random.choice(letters)
    for j in range(12):
        new_password += password.pop()
    return new_password
  
if __name__ == '__main__':
    key = ''
    while key != 'q':
        my_passwd = create_password()
        print("You can use: ", my_passwd, " as your password.")
        key = input("To create new one press 'c' or to quit press 'q': ")