Can't get function to add an item to a dictionnary

Question

I'm a beginner in coding and I've got a function here that is supposed to add a key to a dictionary when it is called. It looks like this:

 def check_inventory(key):
    if items["inventory"] >= 1 and items[key] not in items:
        items[key] = 1
        items["inventory"] -= items["inventory"]
    elif items["inventory"] >= 1 and items[key] in items:
        items[key] += 1
        items["inventory"] -= items["inventory"]
    elif items["inventory"] < 1:
        return False
        print "inventory full"

Basically, if the inventory key is bigger or equal to one, and the key is not already in the items dictionary, I want the function to decrease the inventory and add the item. If inventory is bigger than one, I want it to add one to the key value. Finally, if inventory is smaller than 1, I want it to print "inventory full"

Here is the items dictionnary:

items = {"inventory": 1}

I call the function like this:

check_inventory("batteries")

this is the error it gives me:

 File "C:\Users\ludov\Desktop\PythonFiles\learnpythonhardway\pers3.py", line 108, in <module>
    check_inventory("batteries")
  File "C:\Users\ludov\Desktop\PythonFiles\learnpythonhardway\pers3.py", line 28, in check_inventory
    if items["inventory"] >= 1 and items[key] not in items:
KeyError: 'batteries'

Anyway hope you all can help me. Also if you can explain the error code, it would be great! Thanks!

`items[key] not in items` isn't how you check whether `key` is a key in `items`. It's how you check whether the value associated with the key `key` in `items` is also itself a key in `items`. — user2357112, Aug 15 '17 at 17:41
@RajanChauhan: No. The `keys` call is unnecessary, and it destroys performance on Python 2. — user2357112, Aug 15 '17 at 17:50
@user2357112 How do you check if a key isn't in a dictionnary then? — , Aug 15 '17 at 17:53

Can't get function to add an item to a dictionnary

0 Answers0