python-magic WindowsError: access violation writing 0x00000000

Question

I installed python-magic (0.4.6) on my Win 7 64bit using pip. I then installed cygwin 1.7.33-2 to provide the needed dlls and created a copy of cygmagic-1.dll named magic1.dll (see

When I run the Python 2.7.6 32bit shell, the "import magic" works fine.

However, a

magic.from_file('c:\user\username\sample.txt')

gives me a

Traceback (most recent call last):  
  File "<stdin>", line 1, in <module>  
  File "c:\Python27\lib\site-packages\magic.py", line 119, in from_file    
    m = _get_magic_type(mime)  
  File "c:\Python27\lib\site-packages\magic.py", line 107, in _get_magic_type  
    i = instances.__dict__[mime] = Magic(mime=mime)  
  File "c:\Python27\lib\site-packages\magic.py", line 55, in __init__
    self.cookie = magic_open(flags)  

WindowsError: exception: access violation writing 0x00000000

Any ideas what causes the this error and how I can fix it? Thank you for your help!

Eryk Sun · Accepted Answer · 2015-03-04T15:56:39.427

The GnuWin32 file package has a 32-bit magic1.dll, along with its dependencies regex2.dll and zlib1.dll. I know from testing that this version works with python-magic. Here's an overview of the steps that I took to test this in 32-bit Python 3.3.

Extract the files to GnuWin32's installation directory:

C:\Temp>set "GNU=C:\Program Files (x86)\GNU"
C:\Temp>7z x -y -o"%GNU%" file-5.03-bin.zip > nul
C:\Temp>7z x -y -o"%GNU%" file-5.03-dep.zip > nul

Set up the environment to find the DLLs and magic file:

C:\Temp>set PATH=%PATH%;%GNU%\bin
C:\Temp>set MAGIC=%GNU%\share\misc\magic

Install python-magic:

C:\Temp>py -3.3-32 -m pip install python-magic  
Collecting python-magic
  Downloading python-magic-0.4.6.tar.gz
Installing collected packages: python-magic
  Running setup.py install for python-magic
Successfully installed python-magic-0.4.6

Verify that it works:

C:\Temp>py -3.3-32                            
Python 3.3.5 (v3.3.5:62cf4e77f785, Mar  9 2014, 10:37:12) 
[MSC v.1600 32 bit (Intel)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> import sys, magic
>>> magic.from_file(sys.executable)
b'PE32 executable for MS Windows (console) Intel 80386 32-bit'

python-magic WindowsError: access violation writing 0x00000000

1 Answers1