How to check if key exists in multidimensional dictionary?

Question

array = {"key1":{"key2":"value"}}

if 'key1' in array:
    if 'key2' in array['key1']:
        print(array['key1']['key2'])
    else
        print(0)

In php it is like this if(isset(array[key1][key2])).

you should edit a bit your question... for example, what is your desired output? I guess your code works...so what do you mean by "how check key"? ...use recursion? — cards, Sep 05 '21 at 13:31

Niel Godfrey Pablo Ponciano · Accepted Answer · 2021-09-05T13:21:56.630

5

Use in to the dict value of array['key1']

if 'key1' in array and 'key2' in array['key1']:

This is equivalent to the explicit form:

if 'key1' in array.keys() and 'key2' in array['key1'].keys():

A side note, if you're only interested in the value, you might want to look at dict.get() which returns the value of the key if present and returns None if not present (unless you set the default argument which would be the one returned instead).

edited Sep 05 '21 at 13:21

answered Sep 05 '21 at 13:16

Niel Godfrey Pablo Ponciano

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I get an error if the key1 does not exist – Ivan_Aka Sep 05 '21 at 13:19
I updated the answer to check on both keys. – Niel Godfrey Pablo Ponciano Sep 05 '21 at 13:22
1

I'd just use `array.get('key1', {}).get('key2', 0)`, so the values would be looked up once – DeepSpace Sep 05 '21 at 13:25

score 2 · Answer 2 · answered Sep 05 '21 at 13:24

2

You can use .get():

>>> array.get("key1", {}).get("key2", 0)

answered Sep 05 '21 at 13:24

not_speshal

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Smart trick passing the `{}` fallback so that it always returns a dict – CIRCLE Nov 19 '22 at 14:43

How to check if key exists in multidimensional dictionary?

2 Answers2