Update change.py

[SwastikaPradhan]

Certainly, I made several changes to the provided code for the purpose of introducing a --diff flag to enable dry-runs and a --fail-on-change flag to exit with code 1 if there are changes without actually refactoring. Here are the key changes I made:

1. Introduced command-line Arguments:
   ->I added the argparse module to parse command-line arguments. This allows the script to accept the file path, --diff, and --fail-on-change flags.

2.Modified refactor_file Function:

->I modified the refactor_file function to accept the --diff flag and pass it to the apply_diff method.

3.Modified apply_diff Method:

->I added a dry_run parameter to the apply_diff method in the Change class. If dry_run is True, it prints the computed diff instead of actually applying the changes.

4.Modified the Main Section:

->I added a check in the main section to exit with code 1 if --fail-on-change is specified and there are changes without actual refactoring (i.e., if --diff is also specified).