capture stdout/stderr output from cython/c modules

[PeterC]

print() statements in python *.py and cython *.pyx modules appear in the Jupyter nb but printf() statements from extern c functions in a cython module appear in the console that launched the Jupyter session.

I have some cython modules with external c functions which printf() and fprintf() info to stdout and stderr. Is it possible to get them to print to the Jupyter notebook like regular python and cython print() statements and if so then how?

Many thanks, Peter

[Matthias Bussonnier]

Hello Peter,

Unfortunately the python redirection is done by monkey patching
sys.stdout/err. It is not easy (maybe likely not possible) to redirect
things that get called from c or cython.
as they access filedescriptors directly.

You can take a look at things like:

http://stackoverflow.com/questions/5081657/how-do-i-prevent-a-c-shared-library-to-print-on-stdout-in-python

Which gives some hacks with file descriptors. Though messing with
filedescriptors like this will probably give unexpected results.

--
M

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