在Python中,如果旨在使其与Py3和Py2兼容的人如何编写用于c++库的Python包装器有什么区别?
还是最初为Py2编写的包装程序对Py3起作用,反之亦然?据我了解,Python包装器是用c++编写的.cxx文件,然后必须对其进行编译。
细节
我问是因为我想安装Aggdraw(用于c++反晶粒几何图形库的包装器),该程序可在Python 2.6-7中使用,但在Python 3.4(Windows 7 32位,通过“PATH = C:/命令行中的“Python27 [或Python34]”和“python setup.py install”)。我的希望是复兴这个令人惊叹的Python 3包装器模块,并希望这里的其他任何人都可以为您提供帮助。
我可以在Python 2.6和2.7上编译它,没有任何问题,而且我同时拥有Visual C++ 2008和2010,所以这不是编译器问题。问题似乎出在实际的.cxx包装器代码中。
难道是Aggdraw包装器只考虑了Python 2x编写(现在已经差不多10年前了),所以它没有考虑到Python 3x中可能出现的问题吗?我最好的猜测是,由于3.4版中已弃用和更改的功能,包装程序无法将某些c++对象/类型转换为Python。
如果有人可以帮助我确定问题所在(请参阅下面的命令行错误代码),我可能会愿意通过.cxx包装程序代码来更改必要的部分?如果我们将其修复,那么我将使用指向“已恢复的”包装器代码的链接来更新此帖子。
如果Python 2和3包装器之间应该没有区别,为什么我在Py3而不是Py2中得到以下错误代码?
谢谢!
原始包装器代码:click here
C:\Users\BIGKIMO\Desktop\aggdraw-master>python setup.py build
=== freetype not available (edit setup.py to enable)
running install
running build
running build_ext
building 'aggdraw' extension
C:\Program Files\Microsoft Visual Studio 10.0\VC\BIN\cl.exe /c /nologo /Ox /MD /
W3 /GS- /DNDEBUG -Iagg2/include -IC:\Python34\include -IC:\Python34\include /Tpa
ggdraw.cxx /Fobuild\temp.win32-3.4\Release\aggdraw.obj
aggdraw.cxx
aggdraw.cxx(124) : error C2440: 'initializing' : cannot convert from 'const char
[5]' to 'Py_ssize_t'
There is no context in which this conversion is possible
aggdraw.cxx(126) : error C2440: 'initializing' : cannot convert from 'destructor
' to 'printfunc'
This conversion requires a reinterpret_cast, a C-style cast or function-
style cast
aggdraw.cxx(128) : error C2440: 'initializing' : cannot convert from 'getattrfun
c' to 'setattrfunc'
This conversion requires a reinterpret_cast, a C-style cast or function-
style cast
aggdraw.cxx(142) : error C2440: 'initializing' : cannot convert from 'const char
[4]' to 'Py_ssize_t'
There is no context in which this conversion is possible
aggdraw.cxx(144) : error C2440: 'initializing' : cannot convert from 'destructor
' to 'printfunc'
This conversion requires a reinterpret_cast, a C-style cast or function-
style cast
aggdraw.cxx(161) : error C2440: 'initializing' : cannot convert from 'const char
[6]' to 'Py_ssize_t'
There is no context in which this conversion is possible
aggdraw.cxx(163) : error C2440: 'initializing' : cannot convert from 'destructor
' to 'printfunc'
This conversion requires a reinterpret_cast, a C-style cast or function-
style cast
aggdraw.cxx(187) : error C2440: 'initializing' : cannot convert from 'const char
[5]' to 'Py_ssize_t'
There is no context in which this conversion is possible
aggdraw.cxx(189) : error C2440: 'initializing' : cannot convert from 'destructor
' to 'printfunc'
This conversion requires a reinterpret_cast, a C-style cast or function-
style cast
aggdraw.cxx(191) : error C2440: 'initializing' : cannot convert from 'getattrfun
c' to 'setattrfunc'
This conversion requires a reinterpret_cast, a C-style cast or function-
style cast
aggdraw.cxx(207) : error C2440: 'initializing' : cannot convert from 'const char
[5]' to 'Py_ssize_t'
There is no context in which this conversion is possible
aggdraw.cxx(209) : error C2440: 'initializing' : cannot convert from 'destructor
' to 'printfunc'
This conversion requires a reinterpret_cast, a C-style cast or function-
style cast
aggdraw.cxx(211) : error C2440: 'initializing' : cannot convert from 'getattrfun
c' to 'setattrfunc'
This conversion requires a reinterpret_cast, a C-style cast or function-
style cast
aggdraw.cxx(488) : error C3861: 'PyString_Check': identifier not found
aggdraw.cxx(489) : error C3861: 'PyString_AS_STRING': identifier not found
aggdraw.cxx(575) : error C3861: 'PyString_Check': identifier not found
aggdraw.cxx(583) : error C3861: 'PyString_AS_STRING': identifier not found
aggdraw.cxx(584) : error C3861: 'PyString_GET_SIZE': identifier not found
aggdraw.cxx(730) : error C3861: 'PyInt_Check': identifier not found
aggdraw.cxx(730) : error C3861: 'PyInt_AS_LONG': identifier not found
aggdraw.cxx(731) : error C3861: 'PyInt_Check': identifier not found
aggdraw.cxx(731) : error C3861: 'PyInt_AS_LONG': identifier not found
aggdraw.cxx(735) : error C3861: 'PyInt_Check': identifier not found
aggdraw.cxx(735) : error C3861: 'PyInt_AS_LONG': identifier not found
aggdraw.cxx(736) : error C3861: 'PyInt_Check': identifier not found
aggdraw.cxx(736) : error C3861: 'PyInt_AS_LONG': identifier not found
aggdraw.cxx(742) : error C3861: 'PyInt_Check': identifier not found
aggdraw.cxx(742) : error C3861: 'PyInt_AS_LONG': identifier not found
aggdraw.cxx(745) : error C3861: 'PyInt_Check': identifier not found
aggdraw.cxx(745) : error C3861: 'PyInt_AS_LONG': identifier not found
aggdraw.cxx(759) : error C3861: 'PyInt_Check': identifier not found
aggdraw.cxx(760) : error C3861: 'PyInt_AsLong': identifier not found
aggdraw.cxx(763) : error C3861: 'PyString_Check': identifier not found
aggdraw.cxx(765) : error C3861: 'PyString_AS_STRING': identifier not found
aggdraw.cxx(788) : error C3861: 'PyString_Check': identifier not found
aggdraw.cxx(789) : error C3861: 'PyString_AS_STRING': identifier not found
aggdraw.cxx(1157) : error C3861: 'PyString_FromStringAndSize': identifier not fo
und
aggdraw.cxx(1289) : error C3861: 'PyString_FromString': identifier not found
aggdraw.cxx(1294) : error C3861: 'Py_FindMethod': identifier not found
aggdraw.cxx(1482) : error C3861: 'Py_FindMethod': identifier not found
aggdraw.cxx(1890) : error C3861: 'Py_FindMethod': identifier not found
aggdraw.cxx(1910) : error C3646: 'initaggdraw' : unknown override specifier
aggdraw.cxx(1911) : error C2091: function returns function
aggdraw.cxx(1911) : error C4430: missing type specifier - int assumed. Note: C++
does not support default-int
aggdraw.cxx(1912) : error C2039: 'ob_type' : is not a member of '_typeobject'
c:\python34\include\object.h(334) : see declaration of '_typeobject'
aggdraw.cxx(1912) : error C2039: 'ob_type' : is not a member of '_typeobject'
c:\python34\include\object.h(334) : see declaration of '_typeobject'
aggdraw.cxx(1913) : error C2039: 'ob_type' : is not a member of '_typeobject'
c:\python34\include\object.h(334) : see declaration of '_typeobject'
aggdraw.cxx(1913) : error C2039: 'ob_type' : is not a member of '_typeobject'
c:\python34\include\object.h(334) : see declaration of '_typeobject'
aggdraw.cxx(1913) : error C2039: 'ob_type' : is not a member of '_typeobject'
c:\python34\include\object.h(334) : see declaration of '_typeobject'
aggdraw.cxx(1915) : error C3861: 'Py_InitModule': identifier not found
aggdraw.cxx(1940) : warning C4508: 'DL_EXPORT' : function should return a value;
'void' return type assumed
最佳答案
Python FFI库(ctype)在每个python版本之间都有变化。您将需要查看更改列表,看看有什么完全不同以及为什么不起作用。
例如,两个Python版本之间的ssizet和字符串不同。
https://docs.python.org/3/whatsnew/3.2.html#ctypes
Differences in ctypes between Python 2 and 3