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pyfatfs is a filesystem module for use with PyFilesystem2 for anyone who needs to access or modify files on a FAT filesystem. It also provides a low-level API that allows direct interaction with a FAT filesystem without PyFilesystem2 abstraction.

pyfatfs supports FAT12/FAT16/FAT32 as well as the VFAT extension (long file names).

It currently is in an early development state and expected to be unstable and contain bugs. On FAT32 filesystems the FSInfo struct, containing the free cluster information used to quickly calculate the free space and easily access information such as the next free cluster in the FAT, is not yet supported, so it will be reported by fsck operations after writes.

pyfatfs is available via PyPI as pyfatfs, so just execute the following command to install the package for your project:

$ pip install pyfatfs

The easiest way to get started with pyfatfs is to use it in conjunction with PyFilesystem2:

Use fs.open_fs to open a filesystem with a FAT FS URL:

import fs
my_fs = fs.open_fs("fat:///dev/sda1")

It is possible to supply query parameters to the URI of the PyFilesystem2 opener to influence certain behavior; it can be compared to mount options. Multiple parameters can be supplied by separating them via ampersand (&).

pyfatfs offers an encoding parameter to allow overriding the default encoding of ibm437 for file names, which was mainly used by DOS and still is the default on Linux.

Any encoding known by Python can be used as value for this parameter, but keep in mind that this might affect interoperability with other systems, especially when the selected encoding/codepage is not native or supported.

Please note that this only affects encoding of the 8DOT3 short file names, not long file names of the VFAT extension, as LFN are always stored as UTF-16-LE.

import fs
my_fs = fs.open_fs("fat:///dev/sda1?encoding=cp1252")

Specify an offset in bytes to skip when accessing the file. That way even complete disk images can be read if the location of the partition is known:

import fs
my_fs = fs.open_fs("fat:///dev/sda?offset=32256")

Preserve case when creating files. This will force LFN entries for all created files that do not match the 8DOT3 rules. This defaults to true but can be disabled by setting preserve_case to false:

import fs
my_fs = fs.open_fs("fat:///dev/sda1?preserve_case=false")

Open filesystem in read-only mode and thus don't allow writes/modifications. This defaults to false but can be enabled by setting read_only to true:

import fs
my_fs = fs.open_fs("fat:///dev/sda1?read_only=true")

Create all timestamps on the filesystem in UTC time rather than local time. Affects all directory entries' creation, modification and access times.

import fs
my_fs = fs.open_fs("fat:///dev/sda1?utc=true")

Tests are located at the tests directory. In order to test your new contribution to pyfatfs just run

$ python setup.py test

from your shell.