Python dictionary in-line list comprehensions

inline_dictionary_list_comprehension.py

import json
from typing import List
from uuid import uuid4

# Sample classes for building our data structure
class Inventory:
    def __init__(self, name: str, express: bool=False):
        self.name = name
        self.express = express
        self.id = str(uuid4())

class Order:
    def __init__(self, first: str, last: str, items: List[Inventory]):
        self.first = first
        self.last = last
        self.items = items
        self.id = str(uuid4())

# Build a sample data set
orders = [
    Order('John', 'Smith', [
        Inventory('Apple', True),
        Inventory('Sausage'),
        Inventory('Eggs')
    ]),
    Order('Hildred', 'Spencer', ()),
    Order('Candice', 'Silvester', [
        Inventory('Ham', True),
        Inventory('Potato', True)
    ]),
]

# Construct a dictionary representing the structure
# Using in-line list comprehensions lets us build the dictionary without needing to
# declare the lists ahead of time.  The final code lets us see the entire dictionary
# structure cleanly in one place!
status = {
    'orders': [
        {
            'name': ' '.join((order.first, order.last)),
            'id': order.id,
            'items': [
                {
                    'name': inventory.name,
                    'id': inventory.id,
                }
            for inventory in order.items if inventory.express  # Nested list comprehension with conditional statement
            ]
        }
        for order in orders  # Simple list comprehension to iterate over the orders in the list
    ]
}

print(json.dumps(status, indent=4))