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javascriptpythonjson
Piya
Piya

Reputation: 11

Json in Python with a var giving error

I have this javascript file which looks like below:

var abc= {
    "a" : {
            "label": "Monthly",
            "URL": "xyz.com",
            "ArchTag": "M",
            "archData": {
                "Feb 2016":"20160229",
                "Jan 2016":"20160129",
                "Dec 2015":"20151231"
}}};

so I want a way to edit this and say add a new month detail. I guess its a json inside javascript. So how can one edit it in a standard way.

Upvotes: 0

Views: 89

Answers (5)

João Pinto
João Pinto

Reputation: 5619

You can use regex to replace the var assignment piece:

with open('file.txt') as json_file:
        data = json_file.read()
        data = re.sub(r'^var\s*\S*\s*=\s*', '', data)
        json_data = json.loads(data)

Upvotes: 0

Steve Jessop
Steve Jessop

Reputation: 279255

If you can rely on the data looking exactly like this every time then you can just hack off the bit that stops it being JSON:

json_data = json.loads('{' + json_file.read().partition('{')[2])

(or use a regex, or whatever you prefer for string manipulation)

You should still beware that JavaScript is not the same as JSON, so you need some confidence that what you're given will always be an assignment of a valid JSON associative array to a variable.

If, on the other hand, you're being passed arbitrary JavaScript and you're expected to evaluate it, then you have a much bigger problem to solve. What if someone gives you var xyz = "Monthly"; var abc = {"label" : xyz, "URL" : "xyz" + "." + "com"}?

You need a JavaScript engine to solve that more general problem, not just a JSON parser. For example, js2py claims to be a complete JavaScript engine written in Python, but I've never used it so I can't recommend or dis-recommend it.

There are also security issues to consider in executing code from untrusted sources, beyond those you consider if all you're doing is parsing JSON from an untrusted source. So if you need to use a JavaScript engine, make sure you properly understand how it is sandboxed.

Upvotes: 4

Mehrdad
Mehrdad

Reputation: 2116

Actually the file content is not json because of the var you mentioned. you should remove that part dynamically:

json_text = json_file.read().replace('var abc=','')
json_data = json.dumps(json_text)
pprint(json_data)

Upvotes: 1

Tayliator
Tayliator

Reputation: 43

If you can not remove var abc of your file, read the file in a string, remove the first characters of the string and load the new string.

  try:
        with open(file) as json_file:
            data = file.read()
            json_data = json.loads(data[9:])
            pprint(json_data)
    except Exception as e:
        print(e)

if it is not always written var abc then start your string at the first { index.

Upvotes: 2

Vincent
Vincent

Reputation: 1044

Your code is Javascript, not JSON...

With this code in JS you just create a new Object.

But JSON IS NOT A LANGUAGE!!.! Json is a solution to efficiency store/transmit datas (as assiocative arrays).

Just try to do not define abc:

Your JSON file:

{
    "a" :
    {
            "label": "Monthly",
            "URL": "xyz.com",
            "ArchTag": "M",
            "archData":
            {
                "Feb 2016":"20160229",
                "Jan 2016":"20160129",
                "Dec 2015":"20151231"
            }
    }
}

Upvotes: 2

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