Book Image

Learning Cython Programming (Second Edition) - Second Edition

By : Philip Herron
Book Image

Learning Cython Programming (Second Edition) - Second Edition

By: Philip Herron

Overview of this book

Cython is a hybrid programming language used to write C extensions for Python language. Combining the practicality of Python and speed and ease of the C language it’s an exciting language worth learning if you want to build fast applications with ease. This new edition of Learning Cython Programming shows you how to get started, taking you through the fundamentals so you can begin to experience its unique powers. You’ll find out how to get set up, before exploring the relationship between Python and Cython. You’ll also look at debugging Cython, before moving on to C++ constructs, Caveat on C++ usage, Python threading and GIL in Cython. Finally, you’ll learn object initialization and compile time, and gain a deeper insight into Python 3, which will help you not only become a confident Cython developer, but a much more fluent Python developer too.
Table of Contents (14 chapters)
Learning Cython Programming Second Edition
Credits
About the Author
Acknowledgments
About the Reviewer
www.PacktPub.com
Preface
Index

Logging from C/C++ into Python


An example of everything brought together is reusing the Python logging module directly from C. We want a few macros, such as info, error, and debug that can all handle a variable number of arguments and works as if we are calling a simple printf method.

To achieve this, we must make a Python logging backend for our C/C++ code. We need an initialization function to tell Python about our output logfile, and some wrappers for each info, error, and debug. We can simply write the public cdef wrappers as:

import logging

cdef public void initLoggingWithLogFile(const char * logfile):
    logging.basicConfig(filename = logfile,
                        level = logging.DEBUG,
                        format = '%(levelname)s %(asctime)s: %(message)s',
                        datefmt = '%m/%d/%Y %I:%M:%S')

cdef public void python_info(char * message):
    logging.info(message)

cdef public void python_debug(char * message):
    logging.debug(message)

cdef public void...