python-extensions

问题 I'm just trying to start off by creating a numpy array before I even start to write my extension. Here is a super simple program: #include <stdio.h> #include <iostream> #include "Python.h" #include "numpy/npy_common.h" #include "numpy/ndarrayobject.h" #include "numpy/arrayobject.h" int main(int argc, char * argv[]) { int n = 2; int nd = 1; npy_intp size = {1}; PyObject* alpha = PyArray_SimpleNew(nd, &size, NPY_DOUBLE); return 0; } This program segfaults on the PyArray_SimpleNew call and I don

问题 I'm just trying to start off by creating a numpy array before I even start to write my extension. Here is a super simple program: #include <stdio.h> #include <iostream> #include "Python.h" #include "numpy/npy_common.h" #include "numpy/ndarrayobject.h" #include "numpy/arrayobject.h" int main(int argc, char * argv[]) { int n = 2; int nd = 1; npy_intp size = {1}; PyObject* alpha = PyArray_SimpleNew(nd, &size, NPY_DOUBLE); return 0; } This program segfaults on the PyArray_SimpleNew call and I don

问题 In a nutshell I try to compile a cython extension called extension2 that cimports a file extension from a self-created package. When building extension2 , I get the error that extension.pxd is not found though this file is exactly at the sepcified path. Details I am building two packages involving cython, a package A and a package B that depends on A . A is a subpacke of a namespace package nsp . That is, the folder structure looks as follows: ├── nsp │ └── A | ├── extension.pxd | ├──

问题 Experimentally, I verified that when a compiled extension.pyd (or .so ) and plain extension.py both exist in the same directory, the .pyd file gets imported first ; the .py is only imported if the .pyd file is not found: In [1]: import extension In [2]: extension.__file__ Out[2]: 'extension.pyd' In [3]: import glob; glob.glob("extension.py*") Out[3]: ['extension.py', 'extension.pyd'] Is that guaranteed to be the same for all versions of Python, and can I rely on this to add logic to the .py

问题 The Python community has published helpful reference material showing how to profile Python code, and the technical details of Python extensions in C or in Cython. I am still searching for tutorials which show, however, for non-trivial Python programs, the following: How to identify the hotspots which will benefit from optimization by conversion to a C extension Just as importantly, how to identify the hotspots which will not benefit from conversion to a C extension Finally, how to make the

问题 I am attempting to write a C extension for python. With the code (below) I get the compiler warning: implicit declaration of function ‘Py_InitModule’ And it fails at run time with this error: undefined symbol: Py_InitModule I have spent literally hours searching for a solution with no joy. I have tried multiple minor changes to syntax, I even found a post suggesting the method has been deprecated. However I find no replacement. Here is the code: #include <Python.h> //a func to calc fib

问题 I've written a Python module that depends on some C extensions. Those C extensions depend in turn on several compiled C libraries. I'd like to be able to distribute this module bundled with all the dependencies. I've put together a minimal example (it can be found on GitHub in its entirety). The directory structure is: $ tree . . ├── README.md ├── poc │ ├── __init__.py │ ├── cython_extensions │ │ ├── __init__.py │ │ ├── cvRoberts_dns.c │ │ ├── cvRoberts_dns.h │ │ ├── helloworld.c │ │ ├──

问题 I need to read local variables from Python in C/C++. When I try to PyEval_GetLocals , I get a NULL. This happens although Python is initialized. The following is a minimal example. #include <iostream> #include <Python.h> Py_Initialize(); PyRun_SimpleString("a=5"); PyObject *locals = PyEval_GetLocals(); std::cout<<locals<<std::endl; //prints NULL (prints 0) Py_Finalize(); In the manual, it says that it returns NULL if no frame is running, but... there's a frame running! What am I doing wrong?

问题 I'm writing a C extension for a python application, and need to test python-specific C code. To do so I need to import Python.h into my C files, but for the life of me I haven't been able to do that. Most tutorials suggest something along the lines of sudo apt-get python-dev, but my system doesn't have apt-get, and even if it did I think it'd be better to have the dev files in my virtualenv. Any idea how to get Python.h into my virtualenv? 回答1: Assuming you are using MacOSX and Python

问题 I want to create a Python extension and I really like the idea of using Cython. Mainly to gain more knowledge about it and to take advantage of speed gains, if any. I have read quite a bit of Cython documentation but I am not a computer scientist (yet) and do not have an in depth knowledge to understand the low-level basics, hence the reason for my following questions: I was just wondering, what happens if I use an externally imported (for example, an ORM or SQL library or any other 3rd party