Python ctypes: loading DLL from from a relative path

Posted by Frederick on Stack Overflow See other posts from Stack Overflow or by Frederick
Published on 2010-06-05T13:16:00Z Indexed on 2010/06/05 13:22 UTC
Read the original article Hit count: 174

Filed under:

python

|

ctypes

I have a Python module, wrapper.py, that wraps a C DLL. The DLL lies in the same folder as the module. Therefore, I use the following code to load it:

myDll = ctypes.CDLL("MyCDLL.dll")

This works if I execute wrapper.py from its own folder. If, however, I run it from elsewhere, ctypes goes looking for DLL in the current working directory and naturally fails.

My question is, is there a way by which I can specify the DLL's path relative to the wrapper instead of the current working directory? This will enable me to ship the two together and allow the user to run/import the wrapper from anywhere.

© Stack Overflow or respective owner

Related posts about python

unmet dependencies in Ubuntu 12.04

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
I tried today to install a dvb-card on my Ubuntu 12.04 (Linux blauhai-linux 3.2.0-25-generic #40-Ubuntu SMP Wed May 23 20:30:51 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux ). The installation failed with an error. After that, i tried to install python (it was already installed but i got this error): linux:~$… >>> More
How can I get sikuli-ide to work?

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
I installed sikuli-ide with sudo apt-get install sikuli-ide Everything was fine until I tried to start it from the terminal. I typed sikuli-ide But the only response I got was [info] locale: en_US The application was not started, furthermore there is no desktop file and sikuli-ide does not… >>> More
Getting PATH right for python after MacPorts install

as seen on Super User - Search for 'Super User'
I can't import some python libraries (PIL, psycopg2) that I just installed with MacPorts. I looked through these forums, and tried to adjust my PATH variable in $HOME/.bash_profile in order to fix this but it did not work. I added the location of PIL and psycopg2 to PATH. I know that Terminal is… >>> More
call python with system() in R to run a python script emulating the python console

as seen on Stack Overflow - Search for 'Stack Overflow'
I want to pass a chunk of Python code to Python in R with something like system('python ...'), and I'm wondering if there is an easy way to emulate the python console in this case. For example, suppose the code is "print 'hello world'", how can I get the output like this in R? >>> print… >>> More
Python - Calling a non python program from python?

as seen on Stack Overflow - Search for 'Stack Overflow'
Hi, I am currently struggling to call a non python program from a python script. I have a ~1000 files that when passed through this C++ program will generate ~1000 outputs. Each output file must have a distinct name. The command I wish to run is of the form: program_name -input -output -o1 -o2… >>> More

Related posts about ctypes

Does Ctypes Structures and POINTERS automatically free the memory when the Python object is deleted?

as seen on Stack Overflow - Search for 'Stack Overflow'
When using Python CTypes there are the Structures, that allow you to clone c-structures on the Python side, and the POINTERS objects that create a sofisticated Python Object from a memory address value and can be used to pass objects by reference back and forth C code. What I could not find on the… >>> More
Odd difference between Python 2.5 and Python 2.6 on MacOS 10.6 using ctypes and libproc proc_pidinfo

as seen on Stack Overflow - Search for 'Stack Overflow'
I'm trying to determine the current working directory of a process given its PID. The command-line utility lsof does something similar. Here's the source to the python script: import ctypes from ctypes import util import sys PROC_PIDVNODEPATHINFO = 9 proc = ctypes.cdll.LoadLibrary(util.find_library("libproc")) print(proc… >>> More
Ctypes pro and con

as seen on Stack Overflow - Search for 'Stack Overflow'
I have heard that Ctypes can cause crashes (or stop errors) in Python and windows. Should I stay away from their use? Where did I hear? It was back when I tried to control various aspects of windows, automation, that sort of thing. I hear of swig, but I see Ctypes more often than not. Any danger… >>> More
Python objects as userdata in ctypes callback functions

as seen on Stack Overflow - Search for 'Stack Overflow'
The C function myfunc operates on a larger chunk of data. The results are returned in chunks to a callback function: int myfunc(const char *data, int (*callback)(char *result, void *userdata), void *userdata); Using ctypes, it's no big deal to call myfunc from Python code, and to have the results… >>> More
ctypes and pointer manipulation

as seen on Stack Overflow - Search for 'Stack Overflow'
I am dealing with image buffers, and I want to be able to access data a few lines into my image for analysis with a c library. I have created my 8-bit pixel buffer in Python using create_string_buffer. Is there a way to get a pointer to a location within that buffer without re-creating a new buffer… >>> More