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robotology / robot-testing-framework

Robot Testing Framework (RTF)
http://robotology.github.io/robot-testing-framework/index.html
GNU Lesser General Public License v2.1
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Support Python3 #37

Open traversaro opened 8 years ago

traversaro commented 8 years ago

https://travis-ci.org/robotology/robot-testing/jobs/96977269

Actual error: 

[ 60%] Building CXX object src/plugins/python/CMakeFiles/RTF_python.dir/src/PythonPluginLoader.cpp.o
/home/travis/build/robotology/robot-testing/src/plugins/python/src/PythonPluginLoader.cpp: In member function ‘RTF::TestCase* RTF::plugin::PythonPluginLoaderImpl::open(std::string)’:
/home/travis/build/robotology/robot-testing/src/plugins/python/src/PythonPluginLoader.cpp:112:49: error: ‘PyString_FromString’ was not declared in this scope
/home/travis/build/robotology/robot-testing/src/plugins/python/src/PythonPluginLoader.cpp:135:52: error: ‘Py_InitModule4’ was not declared in this scope
/home/travis/build/robotology/robot-testing/src/plugins/python/src/PythonPluginLoader.cpp: In member function ‘std::string RTF::plugin::PythonPluginLoaderImpl::getPythonErrorString()’:
/home/travis/build/robotology/robot-testing/src/plugins/python/src/PythonPluginLoader.cpp:183:37: error: ‘PyString_Check’ was not declared in this scope
/home/travis/build/robotology/robot-testing/src/plugins/python/src/PythonPluginLoader.cpp:184:44: error: ‘PyString_AsString’ was not declared in this scope
/home/travis/build/robotology/robot-testing/src/plugins/python/src/PythonPluginLoader.cpp:191:37: error: ‘PyString_Check’ was not declared in this scope
/home/travis/build/robotology/robot-testing/src/plugins/python/src/PythonPluginLoader.cpp:192:60: error: ‘PyString_AsString’ was not declared in this scope
/home/travis/build/robotology/robot-testing/src/plugins/python/src/PythonPluginLoader.cpp: In member function ‘virtual bool RTF::plugin::PythonPluginLoaderImpl::setup(int, char**)’:
/home/travis/build/robotology/robot-testing/src/plugins/python/src/PythonPluginLoader.cpp:231:52: error: ‘PyString_FromString’ was not declared in this scope
make[2]: *** [src/plugins/python/CMakeFiles/RTF_python.dir/src/PythonPluginLoader.cpp.o] Error 1
make[1]: *** [src/plugins/python/CMakeFiles/RTF_python.dir/all] Error 2
make: *** [all] Error 2

Googling for similar errors it appears that the bug is caused by a mismatch between the Python versions: https://bugs.launchpad.net/opencog/+bug/1063039 http://sourceforge.net/p/robotcub/mailman/robotcub-hackers/thread/4AB3E428.5020601@alum.mit.edu/

Probably now the Travis images have been update to have multiple versions of Python, and there is a bug in the CMake code handling Python versions. I will look into it.

apaikan commented 8 years ago

@traversaro which versions of python have been installed?

anyway, there is a cmake option RTF_USE_PYTHON_VERSION to force using specific version of python for binding. can you please check it?

traversaro commented 8 years ago

Checked it, the problem is that some RTF is not compatible with Python 3. Working on it right now.

traversaro commented 8 years ago

Relevant link: https://docs.python.org/2/howto/cporting.html .

traversaro commented 8 years ago

Giving up as for the moment I don't know enough of Python internals to do it (especially to properly substitute the Py_InitModule4 function), just preselecting Python 2 in the cmake for now and opening a new issue to track Python 3 support.

traversaro commented 6 years ago

Relevant: https://pythonclock.org/ .

traversaro commented 5 years ago

The Python clock is rapidly ticking. : ) If we do not think we can commit effort to fix this, probably the cleanest thing to do is just to drop Python support in RTF. @aerydna @drdanz @lornat75

apaikan commented 5 years ago

Hi guys, allways glad to hear from you even it is an issue ;) I am a bit out of the discussion. we are using RTF mostly woth python (2.7) and everything is fine. is the main issue with Python 3.x?

traversaro commented 5 years ago

Hi @apaikan , happy to hear from you, hope everything is ok.

Back in the days I tried to get RTF to work on Python 3, but I was unable to port all the part using Py_InitModule4 (around https://github.com/robotology/robot-testing/blob/c7c00459f721648c8f74f973a881d9078a206c50/src/plugins/python/src/PythonPluginLoader.cpp#L134) to use Python 3, that changed that APIs. https://docs.python.org/3/howto/cporting.html is probably useful, but I was unable to get it to work.

Given that Python 2 will be officially unsupported in less than 10 months (see https://pythonclock.org/) I was trying to raise awareness on this issue.

Nicogene commented 5 years ago

Given that Python 2 will be officially unsupported in less than 10 months (see https://pythonclock.org/) I was trying to raise awareness on this issue.

I didn't know about it... WONDERFUL :heart:

I agree, or we port it, or we drop it :grimacing:

aerydna commented 5 years ago

i am for dropping the compatibility

drdanz commented 5 years ago

2 months left to python 2 end of life, and still no python 3 support :disappointed:

Nicogene commented 5 years ago

But what is the main incompatibility issue? What it is blocking ?

traversaro commented 5 years ago

The C API of the Python interpreter changed between Python 2 and Python 3, and we use it in https://github.com/robotology/robot-testing-framework/blob/c7c00459f721648c8f74f973a881d9078a206c50/src/plugins/python/src/PythonPluginLoader.cpp#L134 . Some notes about a previous failed attempt to port (but I did not spent a lot of time on it) can be found in https://github.com/robotology/robot-testing-framework/issues/37#issuecomment-459850630 .

drdanz commented 4 years ago

Python 2 reached its end of life