如果你使用的是Windows操作系统，你可以:

通过以下方式安装pywin32模块:

PIP安装pywin32

然后编码如下:

import win32com.client as com

def get_folder_size(path):
   try:
       fso = com.Dispatch("Scripting.FileSystemObject")
       folder = fso.GetFolder(path)
       size = str(round(folder.Size / 1048576))
       print("Size: " + size + " MB")
   except Exception as e:
       print("Error --> " + str(e))

这将遍历所有子目录;文件大小总和:

import os

def get_size(start_path = '.'):
    total_size = 0
    for dirpath, dirnames, filenames in os.walk(start_path):
        for f in filenames:
            fp = os.path.join(dirpath, f)
            # skip if it is symbolic link
            if not os.path.islink(fp):
                total_size += os.path.getsize(fp)

    return total_size

print(get_size(), 'bytes')

和一个在线的乐趣使用操作系统。listdir(不包括子目录):

import os
sum(os.path.getsize(f) for f in os.listdir('.') if os.path.isfile(f))

参考:

os.path.getsize -以字节为单位给出大小 os.walk os.path.islink

更新 使用os.path。Getsize，这比使用os.stat()更清楚。st_size方法。

感谢ghostdog74指出这一点!

操作系统。stat - st_size以字节为单位给出大小。也可用于获取文件大小等文件相关信息。

import os

nbytes = sum(d.stat().st_size for d in os.scandir('.') if d.is_file())

更新2018

如果您使用的是Python 3.4或更早版本，那么您可以考虑使用第三方scandir包提供的更有效的walk方法。在Python 3.5及以后版本中，此包已合并到标准库和操作系统中。行走得到了相应的性能提升。

更新2019

最近我越来越多地使用pathlib，这里有一个pathlib解决方案:

from pathlib import Path

root_directory = Path('.')
sum(f.stat().st_size for f in root_directory.glob('**/*') if f.is_file())

使用pathlib，我想出了这个一行程序来获取文件夹的大小:

sum(file.stat().st_size for file in Path(folder).rglob('*'))

这是我为一个漂亮的格式化输出:

from pathlib import Path


def get_folder_size(folder):
    return ByteSize(sum(file.stat().st_size for file in Path(folder).rglob('*')))


class ByteSize(int):

    _KB = 1024
    _suffixes = 'B', 'KB', 'MB', 'GB', 'PB'

    def __new__(cls, *args, **kwargs):
        return super().__new__(cls, *args, **kwargs)

    def __init__(self, *args, **kwargs):
        self.bytes = self.B = int(self)
        self.kilobytes = self.KB = self / self._KB**1
        self.megabytes = self.MB = self / self._KB**2
        self.gigabytes = self.GB = self / self._KB**3
        self.petabytes = self.PB = self / self._KB**4
        *suffixes, last = self._suffixes
        suffix = next((
            suffix
            for suffix in suffixes
            if 1 < getattr(self, suffix) < self._KB
        ), last)
        self.readable = suffix, getattr(self, suffix)

        super().__init__()

    def __str__(self):
        return self.__format__('.2f')

    def __repr__(self):
        return '{}({})'.format(self.__class__.__name__, super().__repr__())

    def __format__(self, format_spec):
        suffix, val = self.readable
        return '{val:{fmt}} {suf}'.format(val=val, fmt=format_spec, suf=suffix)

    def __sub__(self, other):
        return self.__class__(super().__sub__(other))

    def __add__(self, other):
        return self.__class__(super().__add__(other))
    
    def __mul__(self, other):
        return self.__class__(super().__mul__(other))

    def __rsub__(self, other):
        return self.__class__(super().__sub__(other))

    def __radd__(self, other):
        return self.__class__(super().__add__(other))
    
    def __rmul__(self, other):
        return self.__class__(super().__rmul__(other))   

用法:

>>> size = get_folder_size("c:/users/tdavis/downloads")
>>> print(size)
5.81 GB
>>> size.GB
5.810891855508089
>>> size.gigabytes
5.810891855508089
>>> size.PB
0.005674699077644618
>>> size.MB
5950.353260040283
>>> size
ByteSize(6239397620)

我还遇到了这个问题，它有一些更紧凑、可能更高效的打印文件大小的策略。

python3.5 +

from pathlib import Path

def get_size(folder: str) -> int:
    return sum(p.stat().st_size for p in Path(folder).rglob('*'))

用法::

In [6]: get_size('/etc/not-exist-path')
Out[6]: 0
In [7]: get_size('.')
Out[7]: 12038689
In [8]: def filesize(size: int) -> str:
   ...:     for unit in ("B", "K", "M", "G", "T"):
   ...:         if size < 1024:
   ...:             break
   ...:         size /= 1024
   ...:     return f"{size:.1f}{unit}"
   ...:

In [9]: filesize(get_size('.'))
Out[9]: '11.5M'

我使用带有scandir的python 2.7.13，这里是我的一行递归函数，以获得文件夹的总大小:

from scandir import scandir
def getTotFldrSize(path):
    return sum([s.stat(follow_symlinks=False).st_size for s in scandir(path) if s.is_file(follow_symlinks=False)]) + \
    + sum([getTotFldrSize(s.path) for s in scandir(path) if s.is_dir(follow_symlinks=False)])

>>> print getTotFldrSize('.')
1203245680

https://pypi.python.org/pypi/scandir

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))])