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pyproj4 / pyproj

Python interface to PROJ (cartographic projections and coordinate transformations library)
https://pyproj4.github.io/pyproj
MIT License
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A question about pyproj/_datadir.pyx #1395

Open Frmcio opened 4 months ago

Frmcio commented 4 months ago

performance hint: pyproj/_datadir.pyx:80:5: Exception check on 'pyproj_log_function' will always require the GIL to be acquired. Possible solutions:

  1. Declare 'pyproj_log_function' as 'noexcept' if you control the definition and you're sure you don't want the function to raise exceptions.

  2. Use an 'int' return type on 'pyproj_log_function' to allow an error code to be returned.

    Error compiling Cython file:

    ...

    cdef void pyproj_context_initialize(PJ_CONTEXT context) except : """ Setup the context for pyproj """ proj_log_func(context, NULL, pyproj_log_function) ^

    pyproj/_datadir.pyx:129:33: Cannot assign type 'void (void , int, const char ) except nogil' to 'PJ_LOG_FUNCTION' (alias of 'void ()(void , int, const char ) noexcept'). Exception values are incompatible. Suggest adding 'noexcept' to the type of 'pyproj_log_function'.

This is my report when I install the sat-bundleadjust. But I find the error. I check the _datadir.pyx and find the 'pyproj_log_function' has been declared as 'noexcept'. WHY the error compiling occur.

snowman2 commented 4 months ago

The signature of the function is determined by PROJ:

https://github.com/OSGeo/PROJ/blob/356e255022cea47bf242bc9e6345a1e87ab1031d/src/proj.h#L383

https://github.com/pyproj4/pyproj/blob/24a7b7f2f05839761c3a6c23de860948a1a9d0f1/pyproj/proj.pxi#L29

I remember trying to make it use noexcept and moving on when it didn't work with some things I tried. Feel free to tinker and see if you can get it to work a different way.

snowman2 commented 3 months ago

I missed your question about why the compiling error. It requires cython 3+. Can you verify that you are using cython 3+?