How to update a value in a nested dictionary in python3?

Question

I have this nested dictionary:

userdict = {'userone': {'valueone': 1, 'valuetwo': 1}}
userdict['usertwo']={'valueone': 1, 'valuetwo': 1}

I process this with:

for i in userdict.keys():
    print(i)
    for j in userdict[i].keys():
        print(j)
    
        userdict[i]={'valuetwo': 0}

After this process i get:

{'userone': {'valuetwo': 0}, 'usertwo': {'valuetwo': 0}}

but i want:

{'userone': {'valueone': 1, 'valuetwo': 0}, 'usertwo': {'valueone': 1, 'valuetwo': 0}}

How can i stop overwriting "valueone"?

Great question. It's well-posed because it has the minimal code to reproduce the issue, it has the output you get, and the expectation. Nice one! — erip
– erip, Commented Jan 23, 2022 at 22:23

erip · Accepted Answer · 2022-01-23 22:21:11Z

1

You're overwriting the entire dictionary at userdict[i], but instead you want to overwrite the entry for userdict[i]['valuetwo'], so

userdict[i]['valuetwo'] = 0

answered Jan 23, 2022 at 22:21

erip

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