apt-dep.py

#!/usr/bin/env python
"""Can check if one packed depends on another and can simplify packets
list by removing dependencies"""

import apt
import sys

cache = apt.Cache()

def all_or_dependencies(dependencies):
  all_dependencies = []
  for dep in dependencies:
    all_dependencies.extend(dep.or_dependencies)
  return all_dependencies

def all_dependencies_recursive(pkg, dependencies):
  pkg_dependencies = all_or_dependencies(pkg.candidate.dependencies)
  for dep in pkg_dependencies:
    if dep.name in dependencies:
      continue
    dependencies.append(dep.name)
    if dep.name in cache:
      all_dependencies_recursive(cache[dep.name], dependencies)

def all_dependencies(pkg):
  dependencies = []
  all_dependencies_recursive(pkg, dependencies)
  return dependencies

def check(pkg, dep):
  for pkg_dep in all_dependencies(cache[pkg]):
    if pkg_dep == dep:
      return True
  return False

def simplify(pkgs):
  result = pkgs[:]
  for pkg1 in pkgs:
    for pkg2 in pkgs:
      if pkg1 == pkg2:
        continue
      if pkg2 not in result:
        continue
      if check(pkg1, pkg2):
        result.remove(pkg2)
  return result

if sys.argv[1] == "check":
  print check(sys.argv[2], sys.argv[3])
elif sys.argv[1] == "simplify":
  print " ".join(simplify(sys.argv[2:]))