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

Typedef and function pointers


The typedef in C/C++ code allows the programmer to give a new name or alias to any type. For example, one could typedef an int to myint. Or you can just simply typedef a struct so that you don't have to refer to the struct with the keyword struct every time. For example, consider this C struct and typedef:

struct foobar {
  int x;
  char * y;
};
typedef struct foobar foobar_t;

In Cython, this can be described by the following:

cdef struct foobar:
    int x
    char * y
ctypedef foobar foobar_t

Note we can also typedef pointer types as below:

ctypedef int * int_ptr

We can also typedef function C/C++ pointers, as follows:

typedef void (*cfptr) (int)

In Cython, this will be as follows:

ctypedef void (*cfptr)(int)

Using the function pointer is just as you would expect:

cdef cfptr myfunctionptr = &myfunc

There is some magic going on here with function pointers as it's simply not safe for raw Python code to directly call a Python function or vice versa. Cython understands...