递归的一行代码:

def getFolderSize(p):
   from functools import partial
   prepend = partial(os.path.join, p)
   return sum([(os.path.getsize(f) if os.path.isfile(f) else getFolderSize(f)) for f in map(prepend, os.listdir(p))])

import os

def get_size(path):
    total_size = 0
    for dirpath, dirnames, filenames in os.walk(path):
        for f in filenames:
            if os.path.exists(fp):
                fp = os.path.join(dirpath, f)
                total_size += os.path.getsize(fp)

    return total_size   # in megabytes

谢谢monkut & troex!

这有点晚了，但只要安装了glob2和humanize，就行了。注意，在Python 3中，默认的iglob具有递归模式。如何修改Python 3的代码是留给读者的简单练习。

>>> import os
>>> from humanize import naturalsize
>>> from glob2 import iglob
>>> naturalsize(sum(os.path.getsize(x) for x in iglob('/var/**'))))
'546.2 MB'

Python 3.6+递归文件夹/文件大小使用os.scandir。和@blakev的回答一样强大，但更短，采用EAFP python风格。

import os

def size(path, *, follow_symlinks=False):
    try:
        with os.scandir(path) as it:
            return sum(size(entry, follow_symlinks=follow_symlinks) for entry in it)
    except NotADirectoryError:
        return os.stat(path, follow_symlinks=follow_symlinks).st_size

当计算子目录的大小时，它应该更新其父目录的文件夹大小，这将一直进行下去，直到它到达根父目录。

下面的函数计算文件夹及其所有子文件夹的大小。

import os

def folder_size(path):
    parent = {}  # path to parent path mapper
    folder_size = {}  # storing the size of directories
    folder = os.path.realpath(path)

    for root, _, filenames in os.walk(folder):
        if root == folder:
            parent[root] = -1  # the root folder will not have any parent
            folder_size[root] = 0.0  # intializing the size to 0

        elif root not in parent:
            immediate_parent_path = os.path.dirname(root)  # extract the immediate parent of the subdirectory
            parent[root] = immediate_parent_path  # store the parent of the subdirectory
            folder_size[root] = 0.0  # initialize the size to 0

        total_size = 0
        for filename in filenames:
            filepath = os.path.join(root, filename)
            total_size += os.stat(filepath).st_size  # computing the size of the files under the directory
        folder_size[root] = total_size  # store the updated size

        temp_path = root  # for subdirectories, we need to update the size of the parent till the root parent
        while parent[temp_path] != -1:
            folder_size[parent[temp_path]] += total_size
            temp_path = parent[temp_path]

    return folder_size[folder]/1000000.0

使用pathlib在Python 3.6上工作的解决方案。

from pathlib import Path

sum([f.stat().st_size for f in Path("path").glob("**/*")])