Question 248190 in Json Question posted in
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How to put certain values of json files on the list with Python?

[
    [
        {
            "indexnum": 677,
            "type": 1,
            "user": 54846,
            "push": 0,
            
        },
        {
            
            "indexnum": 2321,
            "type": 1,
            "user": 77924,
            "push": 0,
            
        }
        
    ]
]

import json


with open('./79553/combined.json', 'r',encoding='UTF-8') as infile:
    my_data = json.load(infile)


datalist1 = []

print(my_data['indexnum'])

That is my saved json file and I want to extract only indexnum from that file

and append them in a new list.

(ex. datalist1 = [677,2321,…])

Whether the file was read successfully, all items were outputted normally when I ‘print(datalist1)’.

but ‘print(my_data[‘indexnum’])’ has ‘list indices must be integers or slices, not str’ error occured.

How to solve them?

try:

I try my_data[0][‘indexnumber’]

same problem

Tags:

4

Answers


  1. 0

    In your example, my_data is the whole json:

    
[
    [
        {
            "indexnum": 677,
            "type": 1,
            "user": 54846,
            "push": 0,
            
        },
        {
            
            "indexnum": 2321,
            "type": 1,
            "user": 77924,
            "push": 0,
            
        }
        
    ]
]

    This is my_data[0]

    [
    {
        "indexnum": 677,
        "type": 1,
        "user": 54846,
        "push": 0,
        
    },
    {
        
        "indexnum": 2321,
        "type": 1,
        "user": 77924,
        "push": 0,
        
    }
    
]

    This is my_data[0][0]

    {
    "indexnum": 677,
    "type": 1,
    "user": 54846,
    "push": 0,
    
}

    This is my_data[0][0][‘indexnum’]

    677
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  2. 0

    Your JSON format is not uniformly equal bracketed. Either the bracketing is made uniform for the entire file or you access it with the correct list command. my_data[0][0]["indexnum"]

    I would highly recommend to use {} brackets througout the whole file.

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  3. 0 
    json_data = '''[
    [
        {
            "indexnum": 677,
            "type": 1,
            "user": 54846,
            "push": 0            
        },
        {
            
            "indexnum": 2321,
            "type": 1,
            "user": 77924,
            "push": 0
        }        
    ]
]'''

import json
my_data = json.loads(json_data)
datalist = [x['indexnum'] for x in my_data[0]]
print(datalist)

    outputs [677, 2321].

    But you need to remote trailing commas in lines like "push": 0, , because it is not valid JSON this way

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  4. 0

    Your json data is formatted as list nested in list

    [
    [
        {
            "indexnum": 677,
            "type": 1,
            "user": 54846,
            "push": 0
            
        },
        {
            
            "indexnum": 2321,
            "type": 1,
            "user": 77924,
            "push": 0
            
        }
        
    ]
]

    Therefore, to get the attribute "indexnum" of the items, you may want to use the double loop after reading the json data

    import json
import os

with open('./79553/combined.json', 'r',encoding='UTF-8') as infile:
    my_data = json.load(infile)


datalist1 = []
for inner_list in my_data:
    for item in inner_list:
        #only append item has the key "indexnum"
        if item.get("indexnum"):
            datalist1.append(item.get('indexnum'))

    If you make sure that the first inner list is the only list you have, use this

    datalist1 = []
for item in my_data[0]:
    #only append item has the key "indexnum"
    if item.get("indexnum"):
        datalist1.append(item.get('indexnum'))

    or the list comprehensive form

    datalist1 = [ item.get('indexnum') for item in my_data[0] if item.get('indexnum')]
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