import os, os.path

def getDirSize(dirPath):
    size = 0
    
    for tuple in os.walk(dirPath):
        dpath, subs, files = tuple
        for f in files:
            realPath = os.path.join(dpath, f)
            size += os.stat(realPath).st_size

    return size

def getDirTuples():
    def isDir(path):  return os.path.isdir(path)

    dirs = filter(isDir, os.listdir(os.getcwd()) )

    def getDirTuple(dirPath):  return ( dirPath, getDirSize(dirPath) )
                                      
    dirTuples = map(getDirTuple, dirs)

    def myCmp(x, y):  return cmp(y[1], x[1])
    
    dirTuples.sort(myCmp)

    return dirTuples

def printDirTuples():
    kilo = 1024
    meg = 1024**2
    gig = 1024**3

    dirTuples = getDirTuples()
    
    if not dirTuples:
        print 'No subdirectories in this directory'
        return
    
    for tuple in dirTuples:
        name, size = tuple[0], int(tuple[1])
        unit = ''

        if size < kilo:
            unit = 'bytes'
        elif size < meg:            # less than a megabyte
            unit = 'KB'
            size /= kilo
        elif size < gig:            # less than a gigabyte
            unit = 'MB'
            size /= meg

        if len(name) > 27:
            name = name[:27] + '...'

        spacing = 40 - len(name)
        spacing = ' ' * spacing
            
        print '%s %s %s %s' % (name, spacing, size, unit)
    return

if __name__ == '__main__':
    printDirTuples()