def list_inventory(inventory):
    """
    Return the inventory in tuple form. Skip any items with a value of zero.

    :param inventory: dict - an inventory dictionary.
    :return: list of tuples - list of key, value pairs from the inventory dictionary.
    """
    inventory_list = []
    for item in inventory:
        if inventory[item] <= 0:
            continue

        inventory_tuple = (item, inventory[item])
        inventory_list.append(inventory_tuple)

    return inventory_list