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
这是我为另一个问题写的东西……
与xApple的答案非常相似,该对象总是以人类可读的格式打印。不同的是,它也是一个适当的int,所以你可以用它做数学! 它将格式说明符直接传递给数字格式,并附加后缀,因此几乎可以保证请求的长度将超出两到三个字符。我从来没有使用过这个代码,所以我没有费心去修复它!
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 = 6239397620
>>> print(size)
5.81 GB
>>> size.GB
5.810891855508089
>>> size.gigabytes
5.810891855508089
>>> size.PB
0.005674699077644618
>>> size.MB
5950.353260040283
>>> size
ByteSize(6239397620)
其他回答
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'
根据之前所有的答案,以下是我的看法。它是一个以字节为单位以整数形式存储文件大小的对象。但是当你尝试打印对象时,你会自动得到一个人类可读的版本。
class Filesize(object):
"""
Container for a size in bytes with a human readable representation
Use it like this::
>>> size = Filesize(123123123)
>>> print size
'117.4 MB'
"""
chunk = 1024
units = ['bytes', 'KB', 'MB', 'GB', 'TB', 'PB']
precisions = [0, 0, 1, 2, 2, 2]
def __init__(self, size):
self.size = size
def __int__(self):
return self.size
def __str__(self):
if self.size == 0: return '0 bytes'
from math import log
unit = self.units[min(int(log(self.size, self.chunk)), len(self.units) - 1)]
return self.format(unit)
def format(self, unit):
if unit not in self.units: raise Exception("Not a valid file size unit: %s" % unit)
if self.size == 1 and unit == 'bytes': return '1 byte'
exponent = self.units.index(unit)
quotient = float(self.size) / self.chunk**exponent
precision = self.precisions[exponent]
format_string = '{:.%sf} {}' % (precision)
return format_string.format(quotient, unit)
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)
使用1000或kibibytes的幂将更符合标准:
def sizeof_fmt(num, use_kibibyte=True):
base, suffix = [(1000.,'B'),(1024.,'iB')][use_kibibyte]
for x in ['B'] + map(lambda x: x+suffix, list('kMGTP')):
if -base < num < base:
return "%3.1f %s" % (num, x)
num /= base
return "%3.1f %s" % (num, x)
附注:永远不要相信一个以K(大写)后缀打印数千的库。
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