python-magic Documentation

python-magic is a Python interface to the libmagic file type identification library. You must install both the Python package and the underlying libmagic C library.

1. Install the Python package:

pip install python-magic

2. Install the libmagic C library based on your OS:

• Debian/Ubuntu:

  sudo apt-get install libmagic1

- **OSX (Homebrew)**:
  ```bash
brew install libmagic

• OSX (MacPorts):

  port install file

- **SmartOS**:
  Install `libmagic` from source and set `LD_LIBRARY_PATH` to `<prefix>/lib`.

'MagicException: could not find any magic files!'

Some installations do not correctly point to the magic database file. You can specify the path explicitly in the constructor:

magic.Magic(magic_file="path_to_magic_file")

'WindowsError: [Error 193] %1 is not a valid Win32 application'

This occurs when attempting to run a 32-bit libmagic DLL in a 64-bit Python build. Ensure you use 64-bit builds of libmagic for Windows.

'WindowsError: exception: access violation writing 0x00000000'

This may indicate a mismatch between Windows Python and Cygwin Python. Ensure your libmagic and Python builds are consistent.

Library not found on OSX

If python-magic fails to load the library, it may be in a non-standard location. Set the DYLD_LIBRARY_PATH environment variable to point to the library location.

Use the top-level functions for simple file type identification.

• magic.from_file(filename, mime=False): Returns a human-readable description of the file type. Set mime=True to return the MIME type.
• magic.from_buffer(buffer, mime=False): Returns the file type from a byte buffer.

Note: It is recommended to use at least the first 2048 bytes of a buffer to avoid incorrect identification.

The Magic class provides more direct control, such as overriding the magic database file or enabling decompression.

Warning: The Magic class is not thread-safe. Attempting to share a Magic instance across multiple threads will cause it to throw an error. It is not recommended for general use unless specific control is required.