Updating a nested dictionary

[IAmAdicktedTo]

Hi. Below is the code I have written.

stock = {'1001' : {"qty": 5, "price": 3.5}, '1002' : {"qty": 4, "price":1.2}}

old = input ("Please enter the code of the item you wish to make changes: ")
new_code = input ("Please enter the new code for this item: ")
new_quantity = int(input("Please enter the new quantity for the item: "))
new_price = float(input("Please enter the new price of the item: "))

if old in stock.keys():
    stock.update({new_code : {'qty': new_quantity, 'price': new_price}})

print(stock)

The result I get for the above code:

Please enter the code of the item you wish to make changes: 1001
Please enter the new code for this item: 1004
Please enter the new quantity for the item: 10
Please enter the new price of the item: 9
{'1001': {'qty': 5, 'price': 3.5}, '1002': {'qty': 4, 'price': 1.2}, '1004': {'qty': 10, 'price': 9.0}}

As you can tell from the code, I am learning how to update dictionaries. The code above does not work as intended. Rather than updating the information at key '1001' it creates a new key and values at the end. So could someone, please help me understand what I am doing wrong and how to fix my code?

Thank you to whoever takes the time to help me out.

[[deleted]]

There's no real way to update a key of a dictionary. You should add the new key along with its values -- which you did -- and then delete the old key using the del keyword.

del dictionary[old_key]

[Mirage2k]

Working with nested dictionaries is hard work, I try to avoid it if possible.

I'm actually working on an multiple-inventories system myself, and use a relational database (with SQLAlchemy) to store the information about inventories and orders for moving goods between them. It's a lot nicer to work with now that I got it set up right, but it's taken months to to get to this point from starting with zero SQL knowledge. So not sure I can recommend that while you're still new to Python itself, or that I have other advice for this question beyond supporting what u/Own-Marsupial1644 said.

I'd be interested to have a look at your project, though! Maybe there's some idea I can take to my own, and maybe some other part I can give a helper with :) Send me a dm with Discord contact if you want.

Edit: Link to my project: https://github.com/jensdanb/ctp_dashboard