.. highlight:: cython .. _language_basics: ***************
Language Basics *************** ================= Cython File
Types ================= There are three file types in Cython: *
Implementation files carry a ``.pyx`` suffix * Definition files
carry a ``.pxd`` suffix * Include files which carry a ``.pxi``
suffix Implementation File =================== What can it
contain? -------------------- * Basically anything Cythonic, but
see below. What can't it contain? ---------------------- * There
are some restrictions when it comes to **extension types**, if
the extension type is already defined else where... **more on
this later** Definition File =============== What can it
contain? -------------------- * Any kind of C type declaration.
* ``extern`` C function or variable declarations. * Declarations
for module implementations. * The definition parts of
**extension types**. * All declarations of functions, etc., for
an **external library** What can't it contain?
---------------------- * Any non-extern C varia