Convert 3 consecutive number in a string with a symbol

I was trying to change every 3 consecutive numbers in string with "@" symbol.
I don’t mean 1.2.3 , but every 3 numbers .

input ="kJF534kdfkj23kk222"

Desired output :

output="kJF@@@kdfkj23kk@@@"

I’m a beginner in Python and I didn’t know how to do that.

I tried the following but I’m having trouble in my for loop.

if i.isdigit() and (i+1).isdigit() and (i+2).isdigit():
    output = input.replace(i, "@")
    output=input.replace(i+1,"@")
    output=input.replace(i+2,"@")

    

>Solution :

I would use regular expressions:

import re

s = "kJF534kdfkj23kk222"
out = re.sub(r"\d{3}","@@@", s)
print(out)

output:

"kJF@@@kdfkj23kk@@@"

This will match every sequence of 3 consecutive digits (\d match a digit, {3} indicates a sequence of 3) and replace them with @@@