Extract json values using just regex

Question

I have a description field that is embedded within json and I'm unable to utilize json libraries to parse this data.

I use {0,23} in order in attempt to extract first 23 characters of string, how to extract entire value associated with description ?

   import re

    description = "'\description\" : \"this is a tesdt \n another test\" "

    re.findall(r'description(?:\w+){0,23}', description, re.IGNORECASE)

For above code just ['description'] is displayed

Answer 1

You could try this code out:

import re

description = "description\" : \"this is a tesdt \n another test\" "

result = re.findall(r'(?<=description")(?:\s*\:\s*)(".{0,23}?(?=")")', description, re.IGNORECASE+re.DOTALL)[0]

print(result)

Which gives you the result of:

"this is a tesdt 
 another test"

Which is essentially:

\"this is a tesdt \n another test\"

And is what you have asked for in the comments.

---

Explanation -

(?<=description") is a positive look-behind that tells the regex to match the text preceded by description"
(?:\s*\:\s*) is a non-capturing group that tells the regex that description" will be followed by zero-or-more spaces, a colon (:) and again zero-or-more spaces.
(".{0,23}?(?=")") is the actual match desired, which consists of a double-quotes ("), zero-to-twenty three characters, and a double-quotes (") at the end.

Answer 2

# First just creating some test JSON

import json

data = {
    'items': [
        {
            'description': 'A "good" thing',

            # This is ignored because I'm assuming we only want the exact key 'description'
            'full_description': 'Not a good thing'
        },
        {
            'description': 'Test some slashes: \\ \\\\ \" // \/ \n\r',
        },
    ]
}

j = json.dumps(data)

print(j)

# The actual code

import re

pattern = r'"description"\s*:\s*("(?:\\"|[^"])*?")'
descriptions = [

    # I'm using json.loads just to parse the matched string to interpret
    # escapes properly. If this is not acceptable then ast.literal_eval
    # will probably also work
    json.loads(d)
    for d in re.findall(pattern, j)]

# Testing that it works

assert descriptions == [item['description'] for item in data['items']]