从字节大小返回人类可读大小的函数:
>>> human_readable(2048)
'2 kilobytes'
>>>
如何做到这一点?
从字节大小返回人类可读大小的函数:
>>> human_readable(2048)
'2 kilobytes'
>>>
如何做到这一点?
当前回答
通过简单的实现(使用f-strings,所以Python 3.6+)解决上述“任务太小,不需要库”的问题:
def sizeof_fmt(num, suffix="B"):
for unit in ["", "Ki", "Mi", "Gi", "Ti", "Pi", "Ei", "Zi"]:
if abs(num) < 1024.0:
return f"{num:3.1f}{unit}{suffix}"
num /= 1024.0
return f"{num:.1f}Yi{suffix}"
支持:
所有当前已知的二进制前缀 负数和正数 大于1000约字节的数字 任意单位(也许你喜欢用吉比特来计数!)
例子:
>>> sizeof_fmt(168963795964)
'157.4GiB'
作者:Fred Cirera
其他回答
我喜欢senderle的十进制版本的固定精度,所以这里有一种与上面joctee的答案的混合(你知道你可以取非整数底数的对数吗?):
from math import log
def human_readable_bytes(x):
# hybrid of https://stackoverflow.com/a/10171475/2595465
# with https://stackoverflow.com/a/5414105/2595465
if x == 0: return '0'
magnitude = int(log(abs(x),10.24))
if magnitude > 16:
format_str = '%iP'
denominator_mag = 15
else:
float_fmt = '%2.1f' if magnitude % 3 == 1 else '%1.2f'
illion = (magnitude + 1) // 3
format_str = float_fmt + ['', 'K', 'M', 'G', 'T', 'P'][illion]
return (format_str % (x * 1.0 / (1024 ** illion))).lstrip('0')
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]
为了以人类可读的形式获取文件大小,我创建了这个函数:
import os
def get_size(path):
size = os.path.getsize(path)
if size < 1024:
return f"{size} bytes"
elif size < pow(1024,2):
return f"{round(size/1024, 2)} KB"
elif size < pow(1024,3):
return f"{round(size/(pow(1024,2)), 2)} MB"
elif size < pow(1024,4):
return f"{round(size/(pow(1024,3)), 2)} GB"
>>> get_size("a.txt")
1.4KB
如果你安装了Django,你也可以试试filesizeformat:
from django.template.defaultfilters import filesizeformat
filesizeformat(1073741824)
=>
"1.0 GB"
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)