编译c程序调用Python

在项目原型阶段，使用Python或者shell来验证程序逻辑和方案是非常快捷的开发方法。而且可以在原型完善以后，通过C语言重写方式来提高性能。

不过，在C/C++代码中嵌入Python，最初也遇到一些问题，记录如下。

我在编译嵌入Python的C程序就遇到过无法找到头文件，以及链接程序的错误，这里为了简化，采用了Python 2.7官方文档Embedding Python in Another Application的样例：

#include <Python.h>

int
main(int argc, char *argv[])
{
  Py_SetProgramName(argv[0]);  /* optional but recommended */
  Py_Initialize();
  PyRun_SimpleString("from time import time,ctime\n"
                     "print 'Today is',ctime(time())\n");
  Py_Finalize();
  return 0;
}

我最初尝试设置

CPPFLAGS=-I/usr/include/python2.7
LDFLAGS=-L/usr/lib/python2.7

但是依然失败

设置编译环境

参考 Can't find Python.h already installed python-dev

C_INCLUDE_PATH=/usr/include/python2.7
export C_INCLUDE_PATH
LD_LIBRARY_PATH=/usr/lib/python2.7
export LD_LIBRARY_PATH

果然不再报告找不到Python.h头文件了

另外一种解决方法参考 Call Python from within C 使用

#include <python2.7/Python.h>

但是改成报错

/cn_nfs/libvirt-kvm/src/qemu/``qemu_driver.cqemuDomainMigratePrepare3Params:13991: undefined reference to `Py_Initialized'
/cn_nfs/qemuDomainMigratePrepare3Paramslibvirt'-kvm/src/qemu/qemu_driver.c:13992: undefined reference 'to: `Py_IsInitialized'
/cn_nfs/libvirt-kvm/src/qemu/:
qemu_driver.c:13999: undefined reference to `Py_Finalize'

//cn_nfs/libvirt-kvm/src/qemu/cn_nfsqemu_driver.c/:13991libvirt:-kvm/src/qemu /qemu_driver.c:13991undefined: undefined  reference to `referencePy_Initializedcollect2: error: ld returned 1 exit status

参考 Undefined reference - despite lib being found by linker ，是因为Py_Initialize需要符号表，从 libpython2.7.a加载，则需要传递编译参数 -lpython2.7

不过，依然报错。

https://ubuntuforums.org/showthread.php?t=987124 有一个解决方法

$ gcc test.c -o test -lpython2.5 -lm -L/usr/lib/python2.5/config/ -I/usr/include/python2.5/
$ ./test
Today is Thu Nov 20 01:05:17 2008

类似 https://bbs.csdn.net/topics/392185678 也是同样解决思路。

修改了环境参数，将

LDFLAGS="-Wl,--as-needed" \
 PYTHON=/usr/bin/python

修改成

LDFLAGS="-Wl,--as-needed -lpython2.7" \
PYTHON=/usr/bin/python

就可以编译成功

另外，参考 https://ubuntuforums.org/showthread.php?t=987124 的简单代码（实际上是 https://docs.python.org/2/extending/embedding.html#very-high-level-embedding ）

#include <Python.h>

int
main(int argc, char *argv[])
{
  Py_SetProgramName(argv[0]);  /* optional but recommended */
  Py_Initialize();
  PyRun_SimpleString("from time import time,ctime\n"
                     "print 'Today is',ctime(time())\n");
  Py_Finalize();
  return 0;
}

参考

Embedding Python in Another Application

Previousc语言中的单行注释和多行注释方法 Next网络

Last updated 5 years ago

Was this helpful?

#include <Python.h> int main(int argc, char *argv[]) { Py_SetProgramName(argv[0]); /* optional but recommended */ Py_Initialize(); PyRun_SimpleString("from time import time,ctime\n" "print 'Today is',ctime(time())\n"); Py_Finalize(); return 0; }

/cn_nfs/libvirt-kvm/src/qemu/``qemu_driver.cqemuDomainMigratePrepare3Params:13991: undefined reference to `Py_Initialized' /cn_nfs/qemuDomainMigratePrepare3Paramslibvirt'-kvm/src/qemu/qemu_driver.c:13992: undefined reference 'to: `Py_IsInitialized' /cn_nfs/libvirt-kvm/src/qemu/: qemu_driver.c:13999: undefined reference to `Py_Finalize' //cn_nfs/libvirt-kvm/src/qemu/cn_nfsqemu_driver.c/:13991libvirt:-kvm/src/qemu /qemu_driver.c:13991undefined: undefined reference to `referencePy_Initializedcollect2: error: ld returned 1 exit status