Quick script tracking Wish Big Win Big tickets

wbwb.py

# System Modules
from collections import OrderedDict, defaultdict
from itertools import chain
import json

# External Modules


# Local Modules

class Prize:
    def __init__(self, name, tickets):
        self.name = name
        self.tickets = set(tickets)

        find.listeners.add(self.listen)
    
    def completion(self, owned_tickets):
        owned_tickets = set(owned_tickets)

        completed = self.tickets & owned_tickets

        missing = completed ^ self.tickets

        return (len(completed) / len(self.tickets), sorted(missing))
    
    def listen(self, ticket_number):
        if ticket_number in self.tickets:
            return self
        else:
            return None
    
    def __str__(self):
        return self.name

    def __repr__(self):
        return "Prize({0.name!r}, {0.tickets})".format(self)

def only(iterable):
    iterable = list(iterable)
    if len(iterable) != 1:
        raise ValueError(
            "iterable must be length 1, got length {0}".format(
            len(iterable)))
    
    return iterable[0]

def get_ticket():
    raw = input("Ticket Number: ")

    try:
        num = int(raw)
    except ValueError:
        num = None
    
    return (raw, num)

def find(number):
    call = (fn(number) for fn in find.listeners)
    try:
        prize = only(p for p in call if p is not None)
    except ValueError:
        print("No matching ticket found.")
        prize = None

    return prize

find.listeners = set()

def main():
    with open("prizes.json", "r") as json_prizes:
        raw_prizes = json.loads(json_prizes.read())
        prizes = [Prize(**kw) for kw in raw_prizes['prizes']]

    with open("tickets.json", "r") as json_tickets:
        owned_tickets = json.loads(json_tickets.read())
    
    def check(ticket):
        if ticket in owned_tickets['tickets']:
            return False
        else:
            return True
    try:
        while True:
            raw, ticket = get_ticket()

            if raw in ("quit", "q"):
                break
            elif ticket is not None:
                prize = find(ticket)
                if prize is None:
                    continue
                elif check(ticket):
                    print("New for {0}. Keeping {1}.".format(prize, ticket))
                    owned_tickets['tickets'].append(ticket)
                else:
                    print("Duplicate.")
    except:
        raise
    finally:
        fmt = "{0} (missing {1}; {2}%)".format
        for p in prizes:
            perc, missing = p.completion(owned_tickets['tickets'])

            print(fmt(p, missing, perc*100))
            
        with open("tickets.json", "w") as json_tickets:
            print("Writing owned tickets to file.", end='')
            json_tickets.write(json.dumps(owned_tickets))
            print(".. done.")

if __name__ == "__main__":
    main()