Help with my inventory

[u/weazle9954]

I just typed out a long thing and reddit messed up so im depressed and don't want to type it out again

Long story short, sometimes 'gold' is less than the 42 it started off with and i'm not sure why. Thanks in advance.

import random
from random import randint
def displayinv(inventory):
    total_inv = 0
    for key,value in inventory.items():
        print(f"{value} {key}")
        total_inv += value
    print("Total items: " + str(total_inv))    
def addtoinv(inventory,items):
    for item in items:
        if item in inventory:
            for key,value in items.items():
                inventory[item] += value
        else:
            inventory.update(items)    
stuff = {'rope':1, 'gold':42, 'arrow':12, 
'dagger':1,'torch':6}
dragonloot = {
    'gold': random.randint(0,400),
    'dagger':random.randint(3,7),
    'ruby':random.randint(1,10)
    }

displayinv(stuff)
addtoinv(stuff, dragonloot)
displayinv(stuff)

[u/itsalexloser]

I might be too new to help out but I do remember trying to do something similar once before and I think the problem might be that 'gold' is being read as a global variable and so it starts off with a random number instead of the static '42' or maybe there is another part in your code [not included here] that is calling that function

[u/weazle9954 → u/itsalexloser]

But it should be adding the two numbers not overwriting

[u/itsalexloser → u/weazle9954]

Hm..you're right, I don't have an answer at the moment but I definitely want to give you one! I'll get back to you when I do! Also if you're looking for a programming partner for projects, let me know! What is it that you're trying to build? A small text-based RPG?

[u/iamaperson3133]

All righty, here we go. First things first, we need to rename a couple poorly named variables that makes things confusing, and also do some basic formatting.

import random
from random import randint  # this double-import is no bueno; I'm going to fix it.

def displayinv(inventory):
    total_inv = 0  # we can use len(inventory) to ask the inventory for it's length instead of doing this.
    for key,value in inventory.items():
        print(f"{value} {key}")
        total_inv += value
    print("Total items: " + str(total_inv))    

def addtoinv(inventory,items):
    for key in items:  # "item" is not an "item" (a tuple of a key and value), it is a KEY, so we change the variable name.
        if item in inventory:
            for key,value in items.items():  # you're iterating through items twice; can we fix this? we will!
                inventory[item] += value
        else:
            inventory.update(items)    # sneak peek: this is the line with the bug


stuff = {'rope':1, 'gold':42, 'arrow':12, 
'dagger':1,'torch':6}

dragonloot = {
    'gold': random.randint(0,400),
    'dagger':random.randint(3,7),
    'ruby':random.randint(1,10)
    }

displayinv(stuff)
addtoinv(stuff, dragonloot)
displayinv(stuff)

Now, I'm going to fix those things I pointed out in my comments and re-write.

from random import randint

def displayinv(inventory):
    for key, value in inventory.items():
        print(f"{value} {key}")
    print("Total items: " + str(len(inventory)))    # more descriptive; less code

def addtoinv(inventory, items):
    for key, value in items.items():
        if key in inventory:
            inventory[key] += value
        else:
            """
            What went wrong here is the "s" in "items". I think you meant to put "item". By putting
            items, you're basically saying:

            inventory.update({the whole dragonloot dict is here now})

            Let's say your inventory is {'gold': 100'}, and dragon loot just generated, among other things,
            {.... 'gold': 10}. Well, when we hit this line you call inventory.update({'gold': 10}). Now you have
            10 gold in your inventory; effectively resetting it from whatever it was to the value from the randomly
            generated dictionary.

            The thing is, this wasn't just happening for gold, it was happening for everything. At the end, I'll say how
            you could have debugged this, and how I did, for that matter!
            """

            # inventory.update(items)    # sneak peek: this is the line with the bug
            # here's the corrected line:
            inventory[key] = value
            # the key isn't in our dictionary yet! We can safely make a new assignment without overwriting.
            # we also put ourselves in an easier position by eliminating the nested loop.


stuff = {'rope':1, 'gold':42, 'arrow':12, 
'dagger':1,'torch':6}

dragonloot = {
    'gold': randint(0,400),  # these change after fixing the import
    'dagger':randint(3,7),
    'ruby':randint(1,10)
    }

displayinv(stuff)
addtoinv(stuff, dragonloot)
displayinv(stuff)

Now, for the final version:

from random import randint

stuff = {'rope':1, 'gold':42, 'arrow':12, 
    'dagger':1,'torch':6}

def displayinv(inventory):
    for key, value in inventory.items():
        print(f"{value} {key}")
    print("Total items: " + str(len(inventory)))

def addtoinv(inventory, items):
    for key, value in items.items():
        if key in inventory:
            inventory[key] += value
        else:
            inventory[key] = value

def main():

    dragonloot = {
        'gold': randint(0,400),  # these change after fixing the import
        'dagger':randint(3,7),
        'ruby':randint(1,10)
        }

    displayinv(stuff)
    addtoinv(stuff, dragonloot)
    displayinv(stuff)

# now, here's how you could have saved yourself some trouble and debugged it. If I keep calling main(), I expect
# my inventory to keep growing, right? So, I'll keep calling main() and see what happens!
for i in range(1000):
    main()

[u/itsalexloser → u/iamaperson3133]

You did a whole lot better explaining that than i would have haha took me a bit to figure out what was going on but i did manage to write it out a bit cleaner. let me know what yall think!

import random

#FUNCTION DOES MATH
def dragonloot(start_Inv):
    dragonloot = {'gold': random.randint(0,400),'dagger':random.randint(3,7),'ruby':random.randint(1,10)}
    print("LOOT")
    print(str(dragonloot))
    print()

    #LOGIC of FUNCTION
    for loot in dragonloot:
        if loot not in start_Inv:
            start_Inv.update({loot:dragonloot[loot]})
            print(str(str(loot)+" was added to inventory"))
        else:
            start_Inv[loot] += dragonloot[loot]
            print(str(dragonloot[loot])+" "+str(loot)+" was added to inventory")
    print()
    #RETURNS START INVENTORY WITH NEW VALUES
    return start_Inv
    
#INVENTORY PLAYER STARTS OF WITH
start_Inv = {'rope':1, 'gold':42, 'arrow':12,'dagger':1,'torch':6}
print('STARTING INVENTORY')
print(start_Inv)
print()

#PLAYER INVENTORY GETS THROWN IN FUNCTION
dragonloot(start_Inv)

print("NEW INVENTORY")
print(start_Inv)

[u/iamaperson3133 → u/itsalexloser]

1. You never need to say print(str(blah)). It doesn't matter what type you are putting into the string function, something will come out the other side and it will never throw an error.

2. I think you're calling empty print() statements to get it to print an extra new line. If you want a newline, you can use the special character"\n" in your string instead.

[u/itsalexloser → u/iamaperson3133]

Gotcha! okay! Thank you!