apt-clean-dependencies

#!/usr/bin/env python
# Check for unneeded dependencies in a dependency list of apt packages

import apt
import sys

SEPARATOR = "\n" + "=" * 80 + "\n"

pkg_list = sys.argv[1:]
cache = apt.Cache()
missing = []
extra_dependencies = set()


def get_dependency_pkg_names(dependency):
    dependency_versions = dependency.target_versions
    return [version.package.name for version in dependency_versions]


for pkg_name in pkg_list:
    package = cache.get(pkg_name)
    if not package:
        missing.append(pkg_name)
        continue
    version = package.versions[0]
    for dependency in version.dependencies:
        for pkg in get_dependency_pkg_names(dependency):
            if pkg in pkg_list:
                extra_dependencies.add(pkg)

print SEPARATOR
print "Missing packages: \n{}".format(" ".join(missing))

print SEPARATOR
print "Unneeded dependencies: \n{}".format(" ".join(extra_dependencies))

print SEPARATOR
print "Cleaned dependency list: \n{}".format(
    " ".join(sorted(set(pkg_list) - extra_dependencies))
)