lstree

#!/usr/bin/env python2.7

import os

def friendly_bytes(num, suffix='B'):
    if num is None:
        return ''

    template = '(%3.1f %s%s)'

    for unit in ['','K','M','G','T','P','E','Z']:
        if abs(num) < 1024.0:
            return template % (num, unit, suffix)
        num /= 1024.0
    return template % (num, 'Y', suffix)


def list_files(startpath):
    for root, dirs, files in os.walk(startpath):
        level = root.replace(startpath, '').count(os.sep)
        indent = ' ' * 4 * (level)
        print('%s%s%s' % (indent, os.path.basename(root), os.sep))
        subindent = ' ' * 4 * (level + 1)

        for f in files:
            if f in ('.DS_Store'):
                continue
            fpath = os.path.join(root, f)
            try:
                fsize = os.stat(fpath).st_size
            except OSError:
                fsize = None

            print('%s%s %s' % (subindent, f, friendly_bytes(fsize)))


if __name__ == '__main__':
    list_files('.')