The primary Python execution environment is commonly referred to as CPython, as it is written in
C. Other major implementations use Java (Jython
[#Jython]_), C# (IronPython [#IronPython]_) and Python
itself (PyPy [#PyPy]_).
C. Other major implementations use:
:Java: Jython [#Jython]_
:C#: IronPython [#IronPython]_)
:Python itself: PyPy [#PyPy]_
Written in C, CPython has been
conducive to wrapping many external libraries that interface through the C language. It has, however, remained non trivial to write the necessary glue code in
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@@ -83,6 +82,18 @@ Where Do I Get It?
Well.. at `cython.org <http://cython.org>`_.. of course!
How Do I Report a Bug?
======================
I Want To Make A Feature Request!
=================================
How Can I Contact You?
=======================
.. rubric:: Footnotes
.. [#Jython] **Jython:** \J. Huginin, B. Warsaw, F. Bock, et al., Jython: Python for the Java platform, http://www.jython.org/
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@@ -96,3 +107,13 @@ Well.. at `cython.org <http://cython.org>`_.. of course!
* The included code can itself contain other ``include`` statements.
===========
Data Typing
===========
====================
Declaring Data Types
====================
.. contents::
:local:
..
I think having paragraphs like this should only be in the tutorial which
we can link to from here
.. note::
.. todo::
I think having paragraphs like this should be somewhere else which we can link to from here
As a dynamic language, Python encourages a programming style of considering classes and objects in terms of their methods and attributes, more than where they fit into the class hierarchy.
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@@ -185,8 +175,8 @@ The ``cdef`` statement is used to make C level declarations for:
tons_of_spam = 3
Grouping
========
Grouping cdef Declarations
==========================
A series of declarations can grouped into a ``cdef`` block::
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@@ -201,21 +191,124 @@ A series of declarations can grouped into a ``cdef`` block::
void f(Spam *s):
print s.tons, "Tons of spam"
Parameters
==========
* All the different **function** types can be declared to have C data types.
* Use normal C declaration syntax.
* **Python callable functions** can also be declared with C data types.
* Both C and Python **function** types can be declared to have parameters C data types.
* Use normal C declaration syntax::
def spam(int i, char *s):
...
cdef int eggs(unsigned long l, float f):
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* As these parameters are passed into a Python declared function, they are magically **converted** to the specified C type value.
* This holds true for only numeric and string types
.. todo::
The previous statement is still true ..??
* If no type is specified for a parameter or a return value, it is assumed to be a Python object
* The following takes two Python objects as parameters and returns a Python object::
cdef spamobjs(x, y):
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* .. note::
This is different then C language behavior, where it is an int by default.
* Python object types have reference counting performed according to the standard Python C-API rules:
* Borrowed references are taken as parameters
* New references are returned
.. todo::
link or label here the one ref count caveat for numpy.
* The name ``object`` can be used to explicitly declare something as a Python Object.
* For sake of code clarity, it recomened to always use ``object`` explicitly in your code.
* This is also useful for cases where the name being declared would otherwise be taken for a type::
cdef foo(object int):
...
* As a return type::
cdef object foo(object int):
...
.. todo::
Do a see also here ..??
Automatic Type Conversion
=========================
* For basic numeric and string types, in most situations, when a Python object is used in the context of a C value and vice versa.
* The following table summarises the conversion possibilities:
