Improve performance by compiling regex once

[Hamidkarimi-h]

Summary

This pull request improves the implementation of the add() function by compiling the regular expression only once instead of on every function call.

Changes

• Compiled the regex pattern using re.compile().
• Simplified the replacement logic.
• Improved code readability.

Benefits

• Slightly better performance.
• Cleaner and easier-to-maintain code.
• No functional changes.