Python - Accessing values from a dictionary - python-3.x

Question

Working on something for fun...completely new to programming. How do I access the values in the dictionary so I can either add the cost values or check if its a "Main" or "Side" item, etc.
from collections import OrderedDict
#Items on menu
item1 = OrderedDict(name = "Regular Pizza",
cost = 20,
item_type = "Main",
size = "Regular")
item2 = OrderedDict(name = "Regular Salad",
cost = 5,
item_type = "Side",
size = "Regular")

Answer 1

Well, first things first.
I see that you are using OrderedDict from collections instead of just using dict. Don't do it, as you are new to Dictionary you should start from "vanilla dict" in my opinion.
OrderedDict as the name suggests is meant to preserve the order of the elements inside it.
But, after Python 3.5 the order preservation feature was implemented to dict, read more in this answer - Difference between dict and ordered dict
Also, as we access the dictionary values by their key, i don't think the order has much use here.
Now for your question on how to access the dictionary elements. Going from your example you have 2 items in the menu.
item1 = {
'name' : 'Regular Pizza',
'cost' : 20,
'item_type' : 'Main',
'size' : 'Regular'
}
item2 = {
'name' : 'Regular Salad',
'cost' : 5,
'item_type' : 'Side',
'size' : 'Regular'
}
Here i have created a dictionary with 2 items. Now
Check if the dish is main or not.
print ('The item is a ' + item1['item_type']+ ' dish')
Adding cost to items.
# increase item1 cost by 5
item1['cost'] += 5
Tip: Further you can put all the dishes inside a list and access them directly by the index values, with that you won't have to create multiple variables such as item1, item2...
The implemention would be like-
food = [
{ 'name' : 'Regular Pizza',
'cost' : 20,
'item_type' : 'Main',
'size' : 'Regular'}
,
{ 'name' : 'Regular Salad',
'cost' : 5,
'item_type' : 'Side',
'size' : 'Regular'}
]
Now to access the elements-
print ('The item is a ' + food[0]['item_type']+ ' dish')
food[0]['cost'] += 5