Dictionary where values are dictionaries not updating

Question

I want to create a dictionary where each value is a dictionary. Here's what I have:

start = 1
for i in range(3):
    updated_payload = payload
    updated_payload["params"]["dsoJsonData"]["ReadMap"]["Some"]["StartIndex"] = start
    x[i] = updated_payload
    start = start + 1

Where payload is also a dictionary with all the needed attributes. I am just changing the StartIndex attribute to whatever the loop is at that time. However, when I run this piece of code all my dictionaries' keys have the same exact values. StartIndex all equal to 3. Why are they all getting the same value and how can I fix it so that it gets its respective iteration number?

Please read https://stackoverflow.com/help/minimal-reproducible-example and provide a complete example. — Karl Knechtel, Sep 28 '21 at 01:03
In particular, notice what some of the answers/comments say about `deepcopy`. — CrazyChucky, Sep 28 '21 at 01:16

score 1 · Answer 1 · answered Sep 28 '21 at 01:05

1

This is because you're referencing those dicts rather than copying them. So all of your x[i]'s are pointing the same dict. You should be copying them as the following:

x[i] = updated_payload.copy()

answered Sep 28 '21 at 01:05

saedx1

984
6
20

For some reason, I'm still getting three's – user2896120 Sep 28 '21 at 01:10

score 1 · Answer 2 · answered Sep 28 '21 at 01:11

1

I think you need to make a copy of the payload dictionary. You are directly assigning the value of payload to updated_payload so it's passed by reference instead of being copied.

updated_payload = payload.copy()

answered Sep 28 '21 at 01:11

Khwarz

11
2

Dictionary where values are dictionaries not updating

2 Answers2