如何使用 python 有条件地修改列表

Question

I have a list

bigdumblist = [(0, 0, {'product_id': 2, 'product_uom_qty': 237}), (0, 0, {'product_id': 1, 'product_uom_qty': 1})]

I want the list to be modified as such

# ***pseudocode*** 
if 'product_id' ==2 change to 3 if 'product_uom_qty' >= 45 divide by 45 

new list

bigdumblist = [((0, 0, {'product_id': 3, 'product_uom_qty': 5})), (0, 0, {'product_id': 1, 'product_uom_qty': 1})]

I have tried to research but have found a way to change the values of certain items on the list. I know I can use indexing to access the list but is there a way to access items on the list based on the items themselves?

Answer 1

Instead of thinking about it as a list, it's easier to think of what you want to do with a single item.

def repair_item(item):
    if item["product_id"] == 2:
        item["product_id"] = 3
    if item["product_uom_qty"] >= 45:
        item["product_uom_qty"] /= 45

Now, simply loop over all the items:

for _, _, item in my_list:
    repair_item(item)

Answer 2

You can just iterate through the list: Below is Python code that does just that:

bigdumblist = [(0, 0, {'product_id': 2, 'product_uom_qty': 237}), (0, 0, {'product_id': 1, 'product_uom_qty': 1})]
for tup in bigdumblist:
    # Iterates through the tuples in bigdumblist
    for item in tup:
        # Checks if the item in the tuple is a dictionary
        if type(item) == dict:
            # Does specified changes to the dictionary
            if item["product_id"] == 2:
                item["product_id"] = 3
            
            if item["product_uom_qty"] >= 45:
                item["product_uom_qty"] /= 45