这个解决方案可能也会吸引你，这取决于你的思维方式:

from pathlib import Path    

def get_size(path = Path('.')):
    """ Gets file size, or total directory size """
    if path.is_file():
        size = path.stat().st_size
    elif path.is_dir():
        size = sum(file.stat().st_size for file in path.glob('*.*'))
    return size

def format_size(path, unit="MB"):
    """ Converts integers to common size units used in computing """
    bit_shift = {"B": 0,
            "kb": 7,
            "KB": 10,
            "mb": 17,
            "MB": 20,
            "gb": 27,
            "GB": 30,
            "TB": 40,}
    return "{:,.0f}".format(get_size(path) / float(1 << bit_shift[unit])) + " " + unit

# Tests and test results
>>> get_size("d:\\media\\bags of fun.avi")
'38 MB'
>>> get_size("d:\\media\\bags of fun.avi","KB")
'38,763 KB'
>>> get_size("d:\\media\\bags of fun.avi","kb")
'310,104 kb'

总有一个这样的人。今天轮到我了。这是一行代码——如果算上函数签名的话是两行。

def human_size(bytes, units=[' bytes','KB','MB','GB','TB', 'PB', 'EB']):
    """ Returns a human readable string representation of bytes """
    return str(bytes) + units[0] if bytes < 1024 else human_size(bytes>>10, units[1:])

>>> human_size(123)
123 bytes
>>> human_size(123456789)
117GB

如果你需要大于1艾字节的大小，那就有点麻烦了:

def human_size(bytes, units=[' bytes','KB','MB','GB','TB', 'PB', 'EB']):
    return str(bytes) + units[0] if bytes < 1024 else human_size(bytes>>10, units[1:]) if units[1:] else f'{bytes>>10}ZB'

重复作为匆匆.filesize()替代方案提供的代码段，下面的代码段根据所使用的前缀给出不同的精度数字。它不像某些片段那样简洁，但我喜欢这样的结果。

def human_size(size_bytes):
    """
    format a size in bytes into a 'human' file size, e.g. bytes, KB, MB, GB, TB, PB
    Note that bytes/KB will be reported in whole numbers but MB and above will have greater precision
    e.g. 1 byte, 43 bytes, 443 KB, 4.3 MB, 4.43 GB, etc
    """
    if size_bytes == 1:
        # because I really hate unnecessary plurals
        return "1 byte"

    suffixes_table = [('bytes',0),('KB',0),('MB',1),('GB',2),('TB',2), ('PB',2)]

    num = float(size_bytes)
    for suffix, precision in suffixes_table:
        if num < 1024.0:
            break
        num /= 1024.0

    if precision == 0:
        formatted_size = "%d" % num
    else:
        formatted_size = str(round(num, ndigits=precision))

    return "%s %s" % (formatted_size, suffix)

你应该用humanize。

>>> humanize.naturalsize(1000000)
'1.0 MB'
>>> humanize.naturalsize(1000000, binary=True)
'976.6 KiB'
>>> humanize.naturalsize(1000000, gnu=True)
'976.6K'

参考: https://pypi.org/project/humanize/

这是我的版本。它不使用for循环。它具有常数复杂度O(1)，理论上比这里使用for循环的答案更有效。

from math import log
unit_list = zip(['bytes', 'kB', 'MB', 'GB', 'TB', 'PB'], [0, 0, 1, 2, 2, 2])
def sizeof_fmt(num):
    """Human friendly file size"""
    if num > 1:
        exponent = min(int(log(num, 1024)), len(unit_list) - 1)
        quotient = float(num) / 1024**exponent
        unit, num_decimals = unit_list[exponent]
        format_string = '{:.%sf} {}' % (num_decimals)
        return format_string.format(quotient, unit)
    if num == 0:
        return '0 bytes'
    if num == 1:
        return '1 byte'

为了更清楚地说明发生了什么，我们可以省略字符串格式化的代码。以下是真正起作用的台词:

exponent = int(log(num, 1024))
quotient = num / 1024**exponent
unit_list[exponent]

def human_readable_data_quantity(quantity, multiple=1024):
    if quantity == 0:
        quantity = +0
    SUFFIXES = ["B"] + [i + {1000: "B", 1024: "iB"}[multiple] for i in "KMGTPEZY"]
    for suffix in SUFFIXES:
        if quantity < multiple or suffix == SUFFIXES[-1]:
            if suffix == SUFFIXES[0]:
                return "%d%s" % (quantity, suffix)
            else:
                return "%.1f%s" % (quantity, suffix)
        else:
            quantity /= multiple