Python Regex: How to match the string and then modify that string by adding something at the end - json

Question

UPDATED CODE: It is working but now the problem is that the code is attaching same random_value to every Path.
Following is my code with a sample chunk of text. I want to read Path and it's value then add (/some unique random alphabet and number combination) at the end of every Path value without changing the already existed value. For example I want the Path to be like
"Path" : "already existed value/1A" e.t.c something like that.
I am unable to make the exact regex pattern of replacing it.
Any help would be appreciated.
It can be done by json parse but the requirement of the task is to do it via REGEX.
from io import StringIO
import re
import string
import random
reader = StringIO("""{
"Bounds": [
{
"HasClip": true,
"Lang": "no",
"Page": 0,
"Path": "//Document/Sect[2]/Aside/P",
"Text": "Potsdam, den 9. Juni 2021 ",
"TextSize": 12.0
}
],
},
{
"Bounds": [
{
"HasClip": true,
"Lang": "de",
"Page": 0,
"Path": "//Document/Sect[3]/P[4]",
"Text": "this is some text ",
"TextSize": 9.0,
}
],
}""")
def id_generator(size=3, chars=string.ascii_uppercase + string.digits):
return ''.join(random.choice(chars) for _ in range(size))
text = reader.read()
random_value = id_generator()
pattern = r'"Path": "(.*?)"'
replacement = '"Path": "\\1/'+random_value+'"'
text = re.sub(pattern, replacement, text)
#This is working but it is only attaching one same random_value on every Path
print(text)

Answer 1

Use group 1 in the replacement:
replacement = '"Path": "\\1/1A"'
See live demo.
The replacement regex \1 puts back what was captured in group 1 of the match via (.*?).

Answer 2

Since you already have a json structure, maybe it would help to use the json module to parse it.
import json
myDict = json.loads("your json string / variable here")
# now myDict is a dictionary that you can use to loop/read/edit/modify and you can then export myDict as json.