• how do you differentiate between a pattern in a key versus a string?
• how do you take into account the fact that JSON doesn’t care about the order of keys whereas regexes do?
• what if there are ] or } inside strings, such that the regex is fooled into thinking the JSON object ended?

Just to illustrate how annoying regex-replaces get once you start trying to satisfy all the syntactic requirements of JSON, here’s a regex-replace I came up with to achieve this while ignoring insignificant whitespace and the order of keys and removing any trailing commas:
find/replace (?-i),\s*{(?:[^{]*{[^}]*}\s*,\s*"model"\s*:\s*"[^"]*KeepInfo[^"]*"\s*|\s*"model"\s*:\s*"[^"]*KeepInfo[^"]*"[^{]*{[^}]*}\s*)}\s*(,)? with \1.

JsonTools is a fine solution for this, if you’re able to use plugins.

Because it uses a JSON parser to parse the JSON, it is insensitive to the formatting of the JSON.

To filter JSON with the plugin, just use Alt-P-J-J (tap the keys in sequence, don’t hold them down simultaneously) to open the tree view, then enter one of the following queries into the query box and hit Ctrl+Enter, then Save query result.
Two queries that accomplish your goals:
@[:][not(@.model =~ `(?i)keepinfo`)] filters out objects where the model includes keepinfo ignoring case.
@[:][not(@.model =~ KeepInfo)] filters out objects where the model includes KeepInfo in that case only.

While I’m here, PythonScript is also an efficient solution:

import json
from Npp import editor

j = json.loads(txt)
filtered = [o for o in j if 'KeepInfo' in o['model']]
filtered_text = json.dumps(filtered, indent=4)
editor.setText(filtered_text)

Yes, indeed, I was mistaken in my first post and @peterjones is right : you must check the Bookmark option, too !

Ah…, Peter, your regex S/R just aims exactly for the OP’s goal and should be quicker than mine. Good point :-))

In free-spacing mode, your regex can be expressed as :

SEARCH (?xis) ^ { (?: (?! KeepInfo ) . )*? ^ },

REPLACE Leave Empty

BR

guy038

Search > Bookmark > Inverse Bookmark

For that to work, you also have to have the Bookmark line checkbox checkmarked… but your instructions said to not have it checkmarked.

how to use the Find and Replace to mass delete the groups that doesn’t have “Keepinfo”

Assuming each group starts with { at the beginning of the line as your example shows (no whitespace prefix) and each group ends with }, _at the beginning of the line as your example shows (no whitespace prefix), then I would do the “simple” version:

• FIND WHAT = (?is)^{(?:(?!KeepInfo).)*?^},
• REPLACE WITH = (leave box empty)
• SEARCH MODE = Regular Expression

I used (?is) to make sure . matches newline is on no matter what the state of your checkbox is, and to make sure match case is off no matter what the state of your checkbox is. I made it case insensitive because your data had KeepInfo but your statement was doesn't have "Keepinfo" – so since I couldn’t be sure of whether all the I from KeepInfo would be upper case, I made the search case insensitive.

My guess is that my assumptions will be too restrictive for your actual data, but this matches what you showed us, so…

Good luck.

-—

Useful References

• Please Read Before Posting
• Template for Search/Replace Questions
• Formatting Forum Posts
• Notepad++ Online User Manual: Searching/Regex
• FAQ: Where to find other regular expressions (regex) documentation

I suppose that marking the lines which contain the KeepInfo string as well as the subsequent lines of the same group is the best bet !

So follow the steps below :

• Open your file in Notepad++

• Open the Mark dialog ( Ctrl + M )

• Type in the regex (?x-is) ^ { \R .+ KeepInfo .+ \R (?: .+ \R)+? (?= { | \Z ) in the Find what: zone

• Uncheck all box options

• Check the Purge for each search and Wrap around options only !

• Select the Regular expression search mode

• Click on the Mark All button

• Then, click on the Search > Bookmark > Inverse Bookmark menu option

• Finally, click on the Search > Bookmark > Remove Bookmark lines menu option

Best Regards,

guy038

Oh ! An other solution could be :

• Right after the Mark All operation, click on the Copy Marked Text button

• Open a new tab ( Ctrl + N )

• Paste the clipboard contents ( Ctrl + V )

• Execute the simple regex S/R to delete the separation lines between each block :

SEARCH ^\R----\R

REPLACE Leave EMPTY