CODEWITHSUNDEEP
pythonjsonpython-3.x
exmatelote
exmatelote

Reputation: 125

Python JSON parser error: json.decoder.JSONDecodeError: Expecting value: line 1 column 1 (char 0)

I need some help parsing JSON file. I've tried a couple of different ways to get the data I need. Below is a sample of the code and also a section of the JSON data but when I run the code I get the error listed above.

There's 500K lines of text in the JSON and it first fails about about 1400 lines in and I can't see anything in that area section to indicate why.

I've run it successfully by only checking blocks of JSON up to the first 1400 lines and I've used a different parser and got the same error.

I'm debating if it's an error in the code, an error in the JSON or a result of the JSON being made of different kids of data as some (like the example below) is for a forklift and others for fixed machines but it is all structured just like below.

All help sincerely appreciate.

Code:

import json

file_list = ['filename.txt'] #insert filename(s) here

for x in range(len(file_list)):

    with open(file_list[x], 'r') as f:
        distros_dict = json.load(f)

#list the headlines to be parsed
for distro in distros_dict:
    print(distro['name'], distro['positionTS'], distro['smoothedPosition'][0], distro['smoothedPosition'][1], distro['smoothedPosition'][2])

And here is a section of the JSON:

{
    "id": "b4994c877c9c",
    "name": "Trukki_0001",
    "areaId": "Tracking001",
    "areaName": "Ajoneuvo",
    "color": "#FF0000",
    "coordinateSystemId": "CoordSys001",
    "coordinateSystemName": null,
    "covarianceMatrix": [
        0.47,
        0.06,
        0.06,
        0.61
    ],
    "position": [
        33.86,
        33.07,
        2.15
    ],
    "positionAccuracy": 0.36,
    "positionTS": 1489363199493,
    "smoothedPosition": [
        33.96,
        33.13,
        2.15
    ],
    "zones": [
        {
            "id": "Zone001",
            "name": "Halli1"
        }
    ],
    "direction": [
        0,
        0,
        0
    ],
    "collisionId": null,
    "restrictedArea": "",
    "tagType": "VEHICLE_MANNED",
    "drivenVehicleId": null,
    "drivenByEmployeeIds": null,
    "simpleXY": "33|33",
    "EventProcessedUtcTime": "2017-03-13T00:00:00.3175072Z",
    "PartitionId": 1,
    "EventEnqueuedUtcTime": "2017-03-13T00:00:00.0470000Z"
}

Upvotes: 3

Views: 6095

Answers (3)

exmatelote
exmatelote

Reputation: 125

The actual problem was that the JSON file was coded in UTF not ASCII. If you change the encoding using something like notepad++ then it will be solved.

Upvotes: 3

Oliver Baumann
Oliver Baumann

Reputation: 2289

I'm guessing that your JSON is actually a list of objects, i.e. the whole stream looks like:

[
    { x:1, y:2 },
    { x:3, y:4 },
    ...
]

... with each element being structured like the section you provided above. This is perfectly valid JSON, and if I store it in a file named file.txt and paste your snippet between a set of [ ], thus making it a list, I can parse it in Python. Note, however, that the result will be again a Python list, not a dict, so you'd iterate like this over each list-item:

import json
import pprint

file_list = ['file.txt']

# Just iterate over the file-list like this, no need for range()
for x in file_list:

    with open(x, 'r') as f:
        # distros is a list!
        distros = json.load(f)

    for distro in distros:
        print(distro['name'])
        print(distro['positionTS'])
        print(distro['smoothedPosition'][1])

        pprint.pprint(distro)

Edit: I moved the second for-loop into the loop over the files. This seems to make more sense, as otherwise you'll iterate once over all files, store the last one in distros, then print elements only from the last one. By nesting the loops, you'll iterate over all files, and for each file iterate over all elements in the list. Hat-tip to the commenters for pointing this out!

Upvotes: 0

adammoyle
adammoyle

Reputation: 309

Using the file provided I got it to work by changing "distros_dict" to a list. In you code you assign distros_dict not add to it, so if more than 1 file were to be read it would assign it to the last one.

This is my implementation

import json

file_list = ['filename.txt'] #insert filename(s) here
distros_list = []

for x in range(len(file_list)):
 with open(file_list[x], 'r') as f:
        distros_list.append(json.load(f))

#list the headlines to be parsed
for distro in distros_list:
    print(distro['name'], distro['positionTS'], distro['smoothedPosition'][0], distro['smoothedPosition'][1], distro['smoothedPosition'][2])

You will be left with a list of dictionaries

Upvotes: 1

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