I've tried to debug memory crash in my Python C extension and tried to run script under valgrind. I found there is too much "noise" in the valgrind output, even if I've ran simple command as: valgrind python -c "" Valgrind output full of repeated info like this: ==12317== Invalid read of size 4 ==12317== at 0x409CF59: PyObject_Fre...
When I build a c extension using python setup.py build, the result is created under a directory named build/lib.linux-x86_64-2.6/ where the part after lib. changes by the OS, CPU and Python version. Is there a way I can access the appropriate string for my current architecture from python? Hopefully in a way that is guaranteed to mat...
I'm using Python ver 2.6.4 There is a function I have to call from a C library when my extension module exits/is unloaded. What would be the equivalent of atexit for a C extension module? ...
I want to define initialized C-array in Pyrex, e.g. equivalent of: unsigned char a[8] = {0,1,2,3,4,5,6,7}; What will be equivalent in Pyrex? Just array is cdef unsigned char a[8] But how can I made it initialized with my values? ...
I've taken a library that is distributed as a binary lib (.a) and header, written some c++ code against it, and want to wrap the results up in a python module. I've done this here. The problem is that when importing this module on Mac OSX (I've tried 10.5 and 10.6), I get the following error: dlopen(/Library/Python/2.5/site-packages/...
I have some code to interface Python to C++ which works fine but every time I look at it I think there must be a better way to do it. On the C++ side there is a 'variant' type that can deal with a fixed range of basic types - int, real, string, vector of variants, etc. I have some code using the Python API to convert from the equivalen...
I'm trying to call a c function from my extension and have narrowed the problem down to this test case. #import "Python.h" ... // Called from python with test_method(0, 0, 'TEST') static PyObject* test_method(PyObject *args) { int ok, x, y, size; const char *s; // this causes Segmentation fault //ok = PyArg_ParseTupl...
I want to run a cpu intensive program in Python across multiple cores and am trying to figure out how to write C extensions to do this. Are there any code samples or tutorials on this? ...
I have code like the following: PyObject *callback; PyObject *paths; // Process and convert arguments if (!PyArg_ParseTuple(args, "OO:schedule", &paths, &callback)) return NULL; What exactly happens inside PyArg_ParseTuple? My guess is that callback gets the function pointer I passed to args (also PyObject...
I have a C extension in which I'd like to use OpenMP. When I import my module, though, I get an import error: ImportError: /home/.../_entropysplit.so: undefined symbol: GOMP_parallel_end I've compiled the module with -fopenmp and -lgomp. Is this because my Python installation wasn't compiled with the -fopenmp flag? Will I have to bui...
I made a c extension out of a python script that was fairly labour intensive. The code itself is well tested and simple. The c extension is called with a few large lists, and it then performs some clever arithmetic and returns a few new lists. The c extension is 100% self sufficient, it doesn't use any other c functions nor does it use a...
I've created a C extension that I'd like to enable in my Python package (using setuptools) only if a command line option is passed in. What is the easiest way to do this? I can't seem to find any straightforward ways of going about this. ...
I'm writing an immutable linked list class in C, but one method is mysteriously segfaulting. The code is intended to be roughly equivalent to this: class PList(object): def __init__(self, first, rest=None): self.first = first self.rest = rest def cons(self, item): return PList(item, self) Here is my c...