python-magic (libmagic python bindings)

example.py

#!/usr/bin/env python
 
# Install (ubuntu/debian):
# ------------------------
# apt-get install python-magic
 
import magic
 
ms = magic.open(magic.MAGIC_NONE)
ms.load()
type =  ms.file("/path/to/some/file")
print type
 
f = file("/path/to/some/file", "r")
buffer = f.read(4096)
f.close()
 
type = ms.buffer(buffer)
print type
 
ms.close()