I would like to have an inventory in ren'py could you give me a model for storing the items and functions for behaviour for removing and adding items.
Of course! In Ren'Py, you can create an inventory system using Python lists and dictionaries. Here's a basic model for an inventory system that includes functions for adding and removing items:

Create a file named inventory.rpy in your Ren'Py project folder.
Paste the following code into the inventory.rpy file:
```
init python:
    class Item(object):
        def __init__(self, name, description):
            self.name = name
            self.description = description

    # Define your items
    item_apple = Item("Apple", "A delicious red apple.")
    item_key = Item("Key", "A small, rusty key.")

    # Inventory list
    inventory = []

    # Function for adding items
    def add_item(item):
        if item not in inventory:
            inventory.append(item)
            return True
        else:
            return False

    # Function for removing items
    def remove_item(item):
        if item in inventory:
            inventory.remove(item)
            return True
        else:
            return False

    # Function for checking if an item is in the inventory
    def has_item(item):
        return item in inventory