Python Cookbook

Computing Directory Sizes in a Cross-Platform Way

Credit: Frank Fejes

Problem

You need to compute the total size of a directory (or set of directories) in a way that works under both Windows and Unix-like platforms.

Solution

There are easier platform-dependent solutions, such as Unix’s du, but Python also makes it quite feasible to have a cross-platform solution:

import os
from os.path import *

class DirSizeError(Exception): pass

def dir_size(start, follow_links=0, start_depth=0, max_depth=0, skip_errs=0):

    # Get a list of all names of files and subdirectories in directory start
    try: dir_list = os.listdir(start)
    except:
        # If start is a directory, we probably have permission problems
        if os.path.isdir(start):
            raise DirSizeError('Cannot list directory %s'%start)
        else:  # otherwise, just re-raise the error so that it propagates
            raise

    total = 0L
    for item in dir_list:
        # Get statistics on each item--file and subdirectory--of start
        path = join(start, item)
        try: stats = os.stat(path)
        except: 
            if not skip_errs:
                raise DirSizeError('Cannot stat %s'%path)
        # The size in bytes is in the seventh item of the stats tuple, so:
        total += stats[6] # recursive descent if warranted if isdir(path) and (follow_links or not islink(path)): bytes = dir_size(path, follow_links, start_depth+1, max_depth) total += bytes if max_depth and (start_depth < max_depth): print_path(path, bytes) return total def print_path(path, bytes, units='b'): if units == 'k': print '%-8ld%s' % (bytes / 1024, path) elif units == 'm': print ...