Call C's dynamic link library with Python

Temporarily python is not well written, some things still write with C handy, encounter this situation how to do it ... So I learned a bit about Python's method of invoking the C Dynamic link library. In this way, a function written in C can be provided to Python for use.

First, you will first create a new DLL project. For example, I created a new dlllearning project with two files in Example.h and Example.cpp.

The code is as follows:

1 //example.h2 #ifndef Export_example_dll3 #defineExample_api __declspec (dllimport)4 #else5 #defineExample_api __declspec (dllexport)6 #endif7 8 9 extern "C" {TenExample_apiintMaxint,int); OneExample_apiintMinint,int); A}

1 //Example.cpp2 #defineExport_example_dll3#include"example.h"4 5Example_apiintMaxintAintb) {6     returna > B?a:b;7 }8 9Example_apiintMinintAintb) {Ten     returnA < b?a:b; One}

Refer to this blog post about the role of __declspec (dllimport): http://blog.csdn.net/mniwc/article/details/7993361

Note that extern "C" is a must, if compiled according to C + +, there will be unexpected problems occur, prompt the following:

Traceback (most recent):    mx = Dlllearning.max (A, b)  File ' E:\Python34\lib\ctypes\__init__.py ', line 364, in __getattr__    func = self.__getitem__ (name)  File ' E:\Python34\lib\ctypes\__init__.py ', line 369, in __ getitem__    func = self._funcptr ((name_or_ordinal, self)) attributeerror:function ' Max ' isn't found[finished in 0.2s]

Compile the build DLL file, and we'll call it with Python.

1  from Import *2 dlllearning = Cdll. LoadLibrary ('dlllearning.dll')3 a = 4134 b =5 /mx = Dlllearning.max (A, b) 6 mn = Dlllearning.min (A, b)7print(MX, MN)

Output Result:

413 52[finished in 0.2s]

Suddenly feel the door of a new World open

Call C's dynamic link library with Python