Fix reverse dependency logic, cleanup output and added support for a

whitelist of packages not to uninstall.
This is a newline separated list of package names in a file
called /etc/deblint/whitelist
Added content to README.md

deblint

@@ -1,9 +1,44 @@
+#!/usr/bin/python3
+
 import os
 import time
 from datetime import datetime, timedelta
 import sys
 
 import apt
+import re
+
+whitelistfile = '/etc/deblint/whitelist'
+
+def import_package_whitelist(file_path):
+    """
+    Import a newline-separated list of package names from a file.
+
+    Args:
+        file_path (str): The path to the file.
+
+    Returns:
+        set: A set of package names.
+    """
+    if not os.path.isfile(file_path):
+        print(f"Error: File {file_path} does not exist.")
+        return set()
+
+    with open(file_path, 'r') as file:
+        packages = file.read().splitlines()
+
+    # Define a regular expression pattern for valid package names
+    pattern = re.compile('^[a-z0-9.:_-]+$')
+
+    # Use the pattern to filter the packages
+    packages = {pkg for pkg in packages if pkg and pattern.match(pkg)}
+
+    if not packages:
+        print(f"Warning: No valid package names found in {file_path}.")
+
+    return packages
+
+whitelist = import_package_whitelist(whitelistfile)
 
 def get_package_files(package_name, cache):
     """
@@ -79,12 +114,13 @@ def filter_safe_to_remove_packages(inactive_packages, cache):
     safe_to_remove = set(inactive_packages)
 
     for package_name in inactive_packages:
+        if package_name in whitelist:
+            continue
         reverse_deps = get_reverse_dependencies(package_name, cache)
         for dep_pkg in reverse_deps:
-            if dep_pkg in safe_to_remove:
+            if dep_pkg not in safe_to_remove:  # changed from safe_to_remove_packages to safe_to_remove
                 safe_to_remove.discard(package_name)
                 break
-
     return list(safe_to_remove)
 
 
@@ -100,10 +136,10 @@ def main():
     days_inactive = int(sys.argv[1]) if len(sys.argv) > 1 else 7
     inactive_packages = check_inactive_packages(days_inactive, cache)
     safe_to_remove_packages = filter_safe_to_remove_packages(inactive_packages, cache)
-
+    print("break")
     if safe_to_remove_packages:
         apt_command = "sudo apt remove " + ' '.join(safe_to_remove_packages)
-        print("Inactive packages that can be safely removed:", safe_to_remove_packages)
+        print("Inactive packages that can be safely removed have been identified.")
         print("Command to remove these packages:", apt_command)
 
         if input("Do you want to uninstall these packages now? (y/n) ").lower() == 'y':