vending.py

# -*- coding: utf-8 -*-
import os
import json


here = os.path.abspath(os.path.dirname(__file__))
DEFAULT_VENDING_SIZE = (12, 4,)  # 4 trays by 12 spaces


# class NoDataFound(Exception):
#     """Raised when there is no pre-existing data."""


# def provision_vending_machine(data_filepath):
#     """\
#     Provision the vending machine's slots from a persistent datastore.
#     """
#     # Create an empty dataset when the data
#     if not os.path.exists(data_filepath):
#         raise NoDataFound()

#     with open(data_filepath, 'r') as f:
#         data = json.loads(f.read())
#     return data


def provision_empty_vending_slots(size=DEFAULT_VENDING_SIZE):
    """\
    Provision a vending machine's data structures and fill it with empty data.
    """
    x, y = size
    return [[None] * x] * y


# def main():
#     # Swap out whatever datastore / persistence layer you'd like.
#     data_filename = 'vending.data'
#     data_filepath = os.path.join(here, data_filename)

#     # Provision the vending slots from the existing data source.
#     try:
#         slots = provision_vending_slots(data_filepath)
#     except NoDataFound:
#         slots = provision_empty_vending_slots()

#     fill_vending_machine(slots)

#     # Write the data out so that it can be reused on next run.
#     write_vending_slots(data_filepath, slots)

#     # Return 0, because it let's the terminal know no errors were encountered.
#     return 0


from pprint import pprint as pp


def get_item_counts(machine, vending_ids):
    items = {}
    for tray in machine:
        for slot in tray:
            items.setdefault(slot, 0)
            items[slot] = items[slot] + 1
    labeled_items = {}
    for key, value in items.items():
        labeled_items[vending_ids[key]] = value
    return labeled_items


def find_item_positon(machine, item_id):
    for x, tray in enumerate(machine):
        for y, slot in enumerate(tray):
            if slot == item_id:  # found!
                return x, y
    

def main():
    machine = provision_empty_vending_slots()

    vending_idents = {None: 'empty', 1: 'cookies', 2: 'candies'}
    
    machine[0] = [1, None] * 6
    machine[1] = [2] * 12

    pp(machine)
    print('-' * 40)
    
    item_count = get_item_counts(machine, vending_idents)
    
    pp(item_count)
    print('-' * 40)


    user_selection = 2

    position = find_item_positon(machine, user_selection)
    print(position)
    x, y = position
    print(machine[x][y])
    print('-' * 40)

    # pp(machine)
    
# When you run the script from the commandline,
# this if statement will evaluate to True.
if __name__ == '__main__':
    main()