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https://github.com/cdgriffith/puremagic

Pure python implementation of identifying files based off their magic numbers
https://github.com/cdgriffith/puremagic

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Pure python implementation of identifying files based off their magic numbers

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README

          

=========
puremagic
=========

puremagic is a pure python module that will identify a file based off
it's magic numbers.

It is designed to be minimalistic and inherently cross platform
compatible. It is also designed to be a stand in for python-magic, it
incorporates the functions from\_file(filename[, mime]) and
from\_string(string[, mime]) however the magic\_file() and
magic\_string() are more powerful and will also display confidence and
duplicate matches.

It does NOT try to match files off non-magic string. In other words it
will not search for a string within a certain window of bytes like
others might.

Advantages over using a wrapper for 'file' or 'libmagic':

- Faster
- Lightweight
- Cross platform compatible
- No dependencies

Disadvantages:

- Does not have as many file types
- No multilingual comments
- Duplications due to small or reused magic numbers

(Help fix the first two disadvantages by contributing!)

Compatibility
~~~~~~~~~~~~~

- Python 3.12+

For use with with 3.7 use the 1.x branch.

Using github ci to run continuous integration tests on listed platforms.

Install from pypy
-----------------

.. code:: bash

$ pip install puremagic

On linux environments, you may want to be clear you are using python3

.. code:: bash

$ python3 -m pip install puremagic

Install from source
-------------------

In either a virtualenv or globally, simply run:

.. code:: bash

$ python setup.py install

Usage
-----

"from_file" will return the most likely file extension. "magic_file"
will give you every possible result it finds, as well as the confidence.

.. code:: python

import puremagic

filename = "test/resources/images/test.gif"

ext = puremagic.from_file(filename)
# '.gif'

puremagic.magic_file(filename)
# [['.gif', 'image/gif', 'Graphics interchange format file (GIF87a)', 0.7],
# ['.gif', '', 'GIF file', 0.5]]

With "magic_file" it gives each match, highest confidence first:

- possible extension(s)
- mime type
- description
- confidence (All headers have to perfectly match to make the list,
however this orders it by longest header, therefore most precise,
first)

If you already have a file open, or raw byte string, you could also use:

* from_string
* from_stream
* magic_string
* magic_stream

.. code:: python

with open(r"test\resources\video\test.mp4", "rb") as file:
print(puremagic.magic_stream(file))

# [PureMagicWithConfidence(byte_match=b'ftypisom', offset=4, extension='.mp4', mime_type='video/mp4', name='MPEG-4 video', confidence=0.8),
# PureMagicWithConfidence(byte_match=b'iso2avc1mp4', offset=20, extension='.mp4', mime_type='video/mp4', name='MP4 Video', confidence=0.8)]

Script
------

*Usage*

.. code:: bash

$ python -m puremagic [options] filename ...

*Examples*

.. code:: bash

$ python -m puremagic test/resources/images/test.gif
'test/resources/images/test.gif' : .gif

$ python -m puremagic -m test/resources/images/test.gif test/resources/audio/test.mp3
'test/resources/images/test.gif' : image/gif
'test/resources/audio/test.mp3' : audio/mpeg

imghdr replacement
------------------

If you are looking for a replacement for the standard library's depreciated imghdr, you can use `puremagic.what()`

.. code:: python

import puremagic

filename = "test/resources/images/test.gif"

ext = puremagic.what(filename)
# 'gif'

FAQ
---

*The file type is actually X but it's showing up as Y with higher
confidence?*

This can happen when the file's signature happens to match a subset of a
file standard. The subset signature will be longer, therefore report
with greater confidence, because it will have both the base file type
signature plus the additional subset one.

Acknowledgements
----------------

Gary C. Kessler

For use of his File Signature Tables, available at:
https://filesig.search.org/

Freedesktop.org

For use of their shared-mime-info file, available at:
https://cgit.freedesktop.org/xdg/shared-mime-info/

License
-------

MIT Licenced, see LICENSE, Copyright (c) 2013-2025 Chris Griffith