minimize-manual.py: Followup with some cleanup, correct permissions

live-build/auto/minimize-manual.py

@@ -1,29 +1,31 @@
 #!/usr/bin/python3
 """Minimize the number of manually installed packages in the image.
 
-Finds all manually meta packages and marks their dependencies as
-automatically installed.
+Finds all manually installed meta packages, and marks their dependencies
+as automatically installed.
 """
-import apt
 import sys
 
+import apt
+
 
 def is_root(pkg):
+    """Check if the package is a root package (manually inst. meta)"""
     return (pkg.is_installed and
             not pkg.is_auto_installed and
             (pkg.section == "metapackages" or
              pkg.section.endswith("/metapackages")))
 
 
-c = apt.Cache(rootdir=sys.argv[1] if len(sys.argv) > 1 else None)
-
-roots = set(pkg for pkg in c if is_root(pkg))
+def main():
+    """Main function"""
+    cache = apt.Cache(rootdir=sys.argv[1] if len(sys.argv) > 1 else None)
+    roots = set(pkg for pkg in cache if is_root(pkg))
     workset = set(roots)
     seen = set()
 
-with c.actiongroup():
+    with cache.actiongroup():
         while True:
-
             print("Iteration", file=sys.stderr)
             to_proc = workset - seen
             if not to_proc:
@@ -31,18 +33,20 @@ with c.actiongroup():
             for pkg in sorted(to_proc):
                 print("    Visiting", pkg, file=sys.stderr)
 
-            # Mark every
                 if pkg not in roots:
                     pkg.mark_auto()
 
-            for dep in pkg.installed.dependencies + pkg.installed.recommends:
-                if dep.rawtype not in ('Depends', 'PreDepends', 'Recommends'):
-                    continue
+                for dep in (pkg.installed.dependencies +
+                            pkg.installed.recommends):
                     for bdep in dep.or_dependencies:
-                    for v in bdep.target_versions:
-                        if v.package.is_installed:
-                            workset.add(v.package)
+                        for ver in bdep.target_versions:
+                            if ver.package.is_installed:
+                                workset.add(ver.package)
 
                 seen.add(pkg)
 
-    c.commit()
+        cache.commit()
+
+
+if __name__ == '__main__':
+    main()