How do I make a password generator that ends once all possible combinations under a character limit have been generated?

So I'm trying to create a password generator that continually generates completely random yet unique sequence of characters that have not been generated before. (the code stops once all possible combinations under the character limit variable have been generated.)

I have this but I understand that it generates duplicates and never ends.

import secrets
import string

letters = string.ascii_letters
digits = string.digits
special_chars = string.punctuation

alphabet = letters + digits + special_chars

while True:
    char_limit = secrets.choice(range(3, 5))
    pwd = ''
    for i in range(char_limit):
        pwd += ''.join(secrets.choice(alphabet))
    print(pwd)

Is there a library for this? A built-in feature? Am I going about it completely the wrong way? Thanks in advance.