Cross-platform space remaining on volume using python

Question

import ctypes
import os
import platform
import sys

def get_free_space_mb(dirname):
    """Return folder/drive free space (in megabytes)."""
    if platform.system() == 'Windows':
        free_bytes = ctypes.c_ulonglong(0)
        ctypes.windll.kernel32.GetDiskFreeSpaceExW(ctypes.c_wchar_p(dirname), None, None, ctypes.pointer(free_bytes))
        return free_bytes.value / 1024 / 1024
    else:
        st = os.statvfs(dirname)
        return st.f_bavail * st.f_frsize / 1024 / 1024

Note that you must pass a directory name for GetDiskFreeSpaceEx() to work (statvfs() works on both files and directories). You can get a directory name from a file with os.path.dirname().

Also see the documentation for os.statvfs() and GetDiskFreeSpaceEx.

Install psutil using pip install psutil. Then you can get the amount of free space in bytes using:

import psutil
print(psutil.disk_usage(".").free)

You could use the wmi module for windows and os.statvfs for unix

for window

import wmi

c = wmi.WMI ()
for d in c.Win32_LogicalDisk():
    print( d.Caption, d.FreeSpace, d.Size, d.DriveType)

for unix or linux

from os import statvfs

statvfs(path)

If you're running python3:

Using shutil.disk_usage()with os.path.realpath('/') name-regularization works:

from os import path
from shutil import disk_usage

print([i / 1000000 for i in disk_usage(path.realpath('/'))])

Or

total_bytes, used_bytes, free_bytes = disk_usage(path.realpath('D:\\Users\\phannypack'))

print(total_bytes / 1000000) # for Mb
print(used_bytes / 1000000)
print(free_bytes / 1000000)

giving you the total, used, & free space in MB.

If you dont like to add another dependency you can for windows use ctypes to call the win32 function call directly.

import ctypes

free_bytes = ctypes.c_ulonglong(0)

ctypes.windll.kernel32.GetDiskFreeSpaceExW(ctypes.c_wchar_p(u'c:\\'), None, None, ctypes.pointer(free_bytes))

if free_bytes.value == 0:
   print 'dont panic'