Create random, unique variable names for objects

I'm playing around with Python and any programming language for the first time, so please bear with me. I started an online class two weeks ago, but try to develop a small game at the side to learn faster (and have fun). It's a text adventure, but is shall have random encounters and fights with enemies that have random equipment that the players can then loot.

This is my problem: If I create random objects/weapons for my random encounter, I need to make sure that the object has a unique name. The way the level is designed there could in theory be an infinite number of objects (it can be open ended, with encounters just popping up).

This is my approach so far

class Item_NPCs: #create objects for NPCs

    def__init__(self, item_type, item_number):
    # e.g. item_type 1 = weapons, item_type2 = potions, etc.

        if item_type == 1 and item number == 1:
             self.property1 = 5
             self.property2 = 4

        if item_type == 1 and item_number ==2:

       # etc. :)

def prepare_encounter(): 

    inventory_NPC = [] # empty list for stuff the NPC carries around

    XXX = Class_Item(item_type, item_number) # I might randomize the arguments.   

What is important is that I want "XXX" to be unique and random, so that no object exists more than once and can later be put into the player's inventory.

How to do that?

Joe