在 Python 类 (SWIG) 中使用从抽象 C++ 类继承的方法 [英] Use method inherited from abtract C++ class in a Python class (SWIG)

问题描述

我目前正在使用 SWIG 使我的主要 C++ 程序中的小模块的实现更容易.类架构如下:

I am currently using SWIG to make the implementation of small modules easier in my main C++ programm. The class architecture is as follow :

foo.hpp :

class Foo
{
public:
  virtual int pureFunc() = 0;
  int func() { return (42); }
};

文件.i:

%module(directors="1") foo
%feature("director") Foo;
%{
  #include "foo.hpp"
%}
%include "foo.hpp"

文件.py:

import sys
sys.path.append('.')
import foo

class Bar(foo.Foo):
    def __init__(self):
        pass
    def pureFunc(self):
        return 21

lol = Bar()
print lol.pureFunc()
print lol.func()

然后我使用以下命令生成 swig 包装器:

I then generate the swig wrappers using the following command :

swig -python -c++ file.i

并像这样编译 .so :

and compile the .so like this :

g++ -fPIC -shared -o _foo.so file_wrap.cxx -I/usr/include/python2.7 -lpython2.7

当我尝试运行 python 脚本时，出现以下错误:

And when I try to run the python script I get the following error :

# python file.py 
21
Traceback (most recent call last):
  File "file.py", line 13, in <module>
    print lol.func()
  File "/home/volent/dev/CPP/cython/foo.py", line 84, in func
    def func(self): return _foo.Foo_func(self)
TypeError: in method 'Foo_func', argument 1 of type 'Foo *'
# _

这表明使用纯方法是有效的，但我不能使用已在 .hpp 文件中定义的方法.

That shows that the use of the pure method is working but I can't use the one already defined in the .hpp file.

我尝试阅读 SWIG 文档，我看到的关于抽象类和继承的唯一内容是 34.4.7 C++ 类 和 34.4.8 C++ 继承.而且我看不到任何提及此类案件的内容.

I have tried to read the SWIG documentation and the only things I see about abstract class and inheritance are 34.4.7 C++ Classes and 34.4.8 C++ Inheritance. And I can't see anything mentionning a case like that.

推荐答案

你忘记调用Bar的父类的__init__方法.用这个替换你的 __init__ 方法:

You have forgotten to call the __init__ method of the parent class of Bar. Replace your __init__ method with this:

class Bar(foo.Foo):
    def __init__(self):
        super(Bar,self).__init__()

这应该让您的 Bar 类知道 Foo 方法.

This should let your Bar class know about the Foo method.

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