#leaf-per-repo
import yum
from sets import Set

def returnLeafNodes(repoid=None):
    """returns a list of package tuples (n,a,e,v,r) that are not required by
       any other package in this repository"""
    
    req = {}
    orphan = []

        
    for po in my.pkgSack.returnPackages(repoid=repoid):
        if not po.requires_names:
            continue
        for r in po.requires_names:
            if not req.has_key(r):
                req[r] = Set()
            req[r].add(po)
 
 
 
    for po in my.pkgSack.returnPackages(repoid=repoid):
        preq = 0
        for p in po.provides_names + po.filelist + po.dirlist + po.ghostlist:
            if req.has_key(p):
                # Don't count a package that provides its require
                s = req[p]
                if len(s) > 1 or po not in s:
                    preq = preq + 1
    
        if preq == 0:
            orphan.append(po)
    
    return orphan


my = yum.YumBase()
for i in returnLeafNodes():
    print i