How can I cumulatively add across python functions?

March 28, 2022

I’m trying the below dictionary twice and want to add amounts 10 and 90 , by running the function separately twice. I’m trying the cumulative total which is 100. However, I keep getting 90 as it doesn’t remember the value outside my function.
I tried making it global variables but to no avail. Thanks

”’

global new_inventory 
global inventory
new_inventory = {}
def add_fruit(inventory, fruit, quantity=0):    
    if inventory == {}: 
        inventory = {fruit:quantity} 
    elif inventory != {}: 
        inventory = inventory.get(fruit,0)+ quantity
    return inventory

add_fruit(new_inventory,'strawberry',10)
add_fruit(new_inventory,'strawberry',90)

”’

>Solution :

Altough using the inventory argument inside the function is unnecessary in this specific use-case, to keep add_fruit more dynamic & flexible I’ll keep it in anyway.

Therefore you could try:

new_inventory = {}

def add_fruit(inventory, fruit, quantity=0):
    if fruit not in inventory.keys():
        inventory[fruit] = quantity
    else:
        inventory[fruit] += quantity

add_fruit(new_inventory, "strawberry", 10)
add_fruit(new_inventory, "strawberry", 90)

print(new_inventory) # {'strawberry': 100}