Cython
cython.readthedocs.io › en › latest › src › userguide › language_basics.html
Language Basics - Cython's Documentation - Read the Docs
The cdef statement and declare() can define function-local and module-level variables as well as attributes in classes, but type annotations only affect local variables and attributes and are ignored at the module level. This is because type annotations are not Cython specific, so Cython keeps the variables in the module dict (as Python values) instead of making them module internal C variables.
Cython
cython.readthedocs.io › en › latest › src › userguide › extension_types.html
Extension Types — Cython 3.3.0a0 documentation
As well as creating normal user-defined classes with the Python class statement, Cython also lets you create new built-in Python types, known as extension types. You define an extension type using the cdef class statement or decorating the class with the @cclass decorator.
Videos
07:01
How to use Cython to create Python wrappers for C libraries - YouTube
08:17
Cython 3.0: Compiling Python to C, the next generation - YouTube
07:56
How to use Cython to speed up Python - YouTube
04:52
Exploring new features in Cython 3.1 - YouTube
Bridging between Static and Dynamic Typing in Cython- P7 ...
10:06
A Cython Typehint Revolution is happening soon... - YouTube
Factsheet
Developer Robert Bradshaw, Stefan Behnel, et al.
First appeared 28 July 2007; 18 years ago (2007-07-28)
Stable release 3.2.4 (4 January 2026; 3 months ago (4 January 2026))
Developer Robert Bradshaw, Stefan Behnel, et al.
First appeared 28 July 2007; 18 years ago (2007-07-28)
Stable release 3.2.4 (4 January 2026; 3 months ago (4 January 2026))
Wikipedia
en.wikipedia.org › wiki › Cython
Cython - Wikipedia
February 4, 2026 - Cython files have a .pyx extension. At its most basic, Cython code looks exactly like Python code. However, whereas standard Python is dynamically typed, in Cython, types can optionally be provided, allowing for improved performance, allowing loops to be converted into C loops where possible.
Cython
cython.readthedocs.io › en › latest › src › quickstart › cythonize.html
Faster code via static typing — Cython 3.3.0a0 documentation
All C types are available for type declarations: integer and floating point types, complex numbers, structs, unions and pointer types. Cython can automatically and correctly convert between the types on assignment. This also includes Python’s arbitrary size integer types, where value overflows ...
Gitbooks
phonchi.gitbooks.io › cython_note › content › cython-basic-typesfunction.html
Cython: Basic Types\/Function · Cython_Note - phonchi
When enabling infer_types, we are taking responsibility to ensure that integer operations do not overflow and that semantics do not change from the untyped version. cdef int *a, *b cdef double golden_ratio cdef double *p_double p_double = &golden_ratio p_double[0] = 1.618 from cython cimport operator print operator.dereference(p_double) cdef st_t *p_st = make_struct() cdef int a_doubled = p_st.a + p_st.a
Cython
cython.readthedocs.io › en › latest › src › userguide › fusedtypes.html
Fused Types (Templates) — Cython 3.3.0a0 documentation
If the same fused type appears more than once in the function arguments, then they will all have the same specialised type: ... @cython.cfunc def cfunc(arg1: my_fused_type, arg2: my_fused_type): # arg1 and arg2 always have the same type here return arg1 + arg2
Nyu-cds
nyu-cds.github.io › python-cython › 01-syntax
Introduction to Cython: Cython Syntax
March 8, 2017 - If Python objects and C values are mixed in an expression, conversions are performed automatically between Python objects and C numeric or string types. Cython supports a range of basic C data types.
Cython
cython.readthedocs.io › en › latest › src › tutorial › cython_tutorial.html
Basic Tutorial — Cython 3.3.0a0 documentation
You’ll notice we declare a Python list exactly the same way it would be in Python. Because the variable result_as_list hasn’t been explicitly declared with a type, it is assumed to hold a Python object, and from the assignment, Cython also knows that the exact type is a Python list.
Cython
docs.cython.org › en › latest › src › userguide › special_methods.html
Special Methods of Extension Types — Cython 3.3.0a0 documentation
Python 3.4 made it possible for extension types to safely define finalizers for objects. When running a Cython module on Python 3.4 and higher you can add a __del__() method to extension types in order to perform Python cleanup operations. When the __del__() is called the object is still in a valid state (unlike in the case of __dealloc__()), permitting the use of Python operations on its class members.
MIT
stuff.mit.edu › afs › sipb › project › sage › packages › cython-0.9.6.8.b › Doc › overview.html
Cython Language Overview
This section describes the basic features of the Cython language. The facilities covered in this section allow you to create Python-callable functions that manipulate C data structures and convert between Python and C data types.
Cython
cython.readthedocs.io › en › latest › src › tutorial › cdef_classes.html
Extension types (aka. cdef classes) — Cython 3.3.0a0 documentation
This allows them to store arbitrary C types in their fields without requiring a Python wrapper for them, and to access fields and methods directly at the C level without passing through a Python dictionary lookup. Normal Python classes can inherit from cdef classes, but not the other way around. Cython requires to know the complete inheritance hierarchy in order to lay out their C structs, and restricts it to single inheritance.
Peterbaumgartner
peterbaumgartner.com › blog › an introduction to just enough cython to be useful
An Introduction to Just Enough Cython to be Useful | Peter Baumgartner
March 1, 2022 - After cpdef you’ll see the the int type, which in Cython syntax declares the return type of the function. One thing you’ll notice is that the types are in a different order than they are if you’re used to typing things for mypy in python.
Sage Q&A Forum
ask.sagemath.org › question › 10304 › what-are-all-the-types-we-can-declare-in-cython
What are all the types we can declare in Cython? - ASKSAGE: Sage Q&A Forum
The biggest speed benefit comes from using C primitive types instead of Python objects, for example machine integers instead of Python / Sage integer objects. Of course thats a pretty small list of types. You can also declare any Cython cdef class, but that mostly saves you from having to cast the Python object to the cdef class all the time.
Cython
cython.readthedocs.io › en › latest › src › tutorial › pure.html
Pure Python Mode - Cython's Documentation - Read the Docs
In pure mode, you are more or less restricted to code that can be expressed (or at least emulated) in Python, plus static type declarations. Anything beyond that can only be done in .pyx files with extended language syntax, because it depends on features of the Cython compiler.
7-Zip Documentation
documentation.help › Cython › extension_types.html
Extension Types - Cython 0.19.1 - Documentation & Help
As well as creating normal user-defined classes with the Python class statement, Cython also lets you create new built-in Python types, known as extension types. You define an extension type using the cdef class statement.
Readthedocs
cythoncython.readthedocs.io › en › latest › src › tutorial › cdef_classes.html
Extension types (aka. cdef classes) — Cython 3.0a0 documentation
This allows them to store arbitrary C types in their fields without requiring a Python wrapper for them, and to access fields and methods directly at the C level without passing through a Python dictionary lookup. Normal Python classes can inherit from cdef classes, but not the other way around. Cython requires to know the complete inheritance hierarchy in order to lay out their C structs, and restricts it to single inheritance.
Cython
cython.readthedocs.io › en › latest › src › reference › language_basics.html
Language Basics — Cython 3.2.0b3 documentation
This section was moved to Overriding in extension types. This section was moved to Built-in Functions. This section was moved to Optional Arguments. This section was moved to Keyword-only Arguments. This section was moved to Error return values. This section was moved to Checking return values of non-Cython ...
Wustl
wangftp.wustl.edu › ~jli › Chip-seq › script › cython › Doc › extension_types.html
Extension Types
Type names vs. constructor names ... As well as creating normal user-defined classes with the Python class statement, Cython also lets you create new built-in Python types, known as extension types. You define an extension type using the cdef class statement.
Cython
cython.readthedocs.io › en › 3.0.x › src › userguide › language_basics.html
Language Basics — Cython 3.0.12 documentation
The Cython language uses the normal C syntax for C types, including pointers. It provides all the standard C types, namely char, short, int, long, long long as well as their unsigned versions, e.g. unsigned int (cython.uint in Python code).