Get actual disk space

How do I get the actual filesize on disk in python? (the actual size it takes on the harddrive).

Thanks.

You mean rouned up by cluster size?
– ruslik
Nov 25 '10 at 8:18

Take a look at this question: stackoverflow.com/questions/2493172/…
– Ruel
Nov 25 '10 at 8:24

@ruslik: It's not that simple. Consider e.g. sparse or compressed files, which can take less space than their size indicates.
– Philipp
Nov 25 '10 at 9:13

5 Answers
5

st = os.stat(…)
du = st.st_blocks * st.st_blksize


+1, didn't realise this was in os.stat! I was about to refer the questioner to win32file.DeviceIoControl. Don't know why I assumed the OP was on Windows :P
– fmark
Nov 25 '10 at 8:30

os.stat

win32file.DeviceIoControl

"On some Unix systems (such as Linux), the following attributes may also be available: st_blocks (number of blocks allocated for file), st_blksize (filesystem blocksize)..." – i.e. that's not portable, and you should at least catch the exception that is raised when these members aren't available.
– Philipp
Nov 25 '10 at 9:15

Careful, this is wrong! On Linux, st.st_blocks is always in units of 512 bytes, while st.st_blksize is a filesystem blocksize (typically 4096 bytes). The real usage is st.st_blocks * 512. See linux.die.net/man/2/stat for details.
– Jim Paris
Aug 5 '13 at 16:24

st.st_blocks

st.st_blksize

st.st_blocks * 512

No, you're both wrong: st.st_blocks is NOT ALWAYS in units of 512 bytes. On my machine it is in units of 1024 (which is strange indeed). Additionally, the answer is wrong because st_blksize does not return 1024, it returns the FILE I/O block size, e.g., st_blksize returns 65536 on my machine. For example, on my dell laptop running python 2.7.8 on cygwin on Windows 7, I created a 3000Byte files ("dd if=/dev/zero bs=3000 count=1 of=./testfile.txt") and: os.stat("testfile.txt").st_blocks=4; os.stat("./testfile.txt").st_blksize=65536; the logical size is 3000, on disk is 4096. I will answer below
– hft
Jan 17 '15 at 23:06

Can you please update your answer to refer to @hft's answer below?
– Miserable Variable
Apr 25 at 18:37

UNIX only:

import os
from collections import namedtuple

_ntuple_diskusage = namedtuple('usage', 'total used free')

def disk_usage(path):
"""Return disk usage statistics about the given path.

Returned valus is a named tuple with attributes 'total', 'used' and
'free', which are the amount of total, used and free space, in bytes.
"""
st = os.statvfs(path)
free = st.f_bavail * st.f_frsize
total = st.f_blocks * st.f_frsize
used = (st.f_blocks - st.f_bfree) * st.f_frsize
return _ntuple_diskusage(total, used, free)


Usage:

>>> disk_usage('/')
usage(total=21378641920, used=7650934784, free=12641718272)
>>>


Edit 1 - also for Windows: https://code.activestate.com/recipes/577972-disk-usage/?in=user-4178764

Edit 2 - this is also available in Python 3.3+: https://docs.python.org/3/library/shutil.html#shutil.disk_usage

Use os.stat(filename).st_size to get the logical size of the file. Use os.statvfs(filename).f_bsize to get the filesystem block size. Then use integer division to compute the correct size on disk, as below:

lSize=os.stat(filename).st_size
bSize=os.statvfs(filename).f_bsize
sizeOnDisk=(lSize/bSize+1)*bSize


((lSize-1)/bSize+1)*bSize) might be slightly more accurate. Thanks for correcting my ancient and wrong answer.
– ephemient
Jan 20 '15 at 16:19

((lSize-1)/bSize+1)*bSize)

no problem whatsoever ;)
– hft
Jan 21 '15 at 16:24

Deprecated since version 2.6: The statvfs module has been removed in Python 3. :-( docs.python.org/2/library/statvfs.html
– danodonovan
Aug 12 '15 at 12:36

Deprecated since version 2.6: The statvfs module has been removed in Python 3.

@danodonovan It looks like the statvfs module has been removed in Python 3, but the answer uses the os module. As you can see, the documentation for Python 3 reveals that os.statvfs is still around and has even been updated to include new functionality as recently as Python 3.6.
– bytesized
Jan 10 '17 at 22:11

statvfs

os

os.statvfs

I'm not certain if this is size on disk, or the logical size:

import os
filename = "/home/tzhx/stuff.wev"
size = os.path.getsize(filename)


If it's not the droid your looking for, you can round it up by dividing by cluster size (as float), then using ceil, then multiplying.

That's not the size on disk.
– Ruel
Nov 25 '10 at 8:21

when I used getsize() in windows7,python 2.2, I did get the actual space file occupies. In my case, I crave for the just "file size" not "file space".I wonder how can you get just the file size
– Allan Ruin
Aug 2 '12 at 17:43

To get the disk usage for a given file/folder, you can do the following:

import os

def disk_usage(path):
"""Return cumulative number of bytes for a given path."""
# get total usage of current path
total = os.path.getsize(path)
# if path is dir, collect children
if os.path.isdir(path):
for file_name in os.listdir(path):
child = os.path.join(path, file_name)
# recursively get byte use for children
total += disk_usage(child)
return total


The function recursively collects byte usage for files nested within a given path, and returns the cumulative use for the entire path.
You could also add a print "{path}: {bytes}".format(path, total) in there if you want the information for each file to print.

print "{path}: {bytes}".format(path, total)

After running multiple tests, on Windows 7 this returns the real size, not the size on disk.
– Steven Byrne
Nov 13 '17 at 17:50

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