mtypes

Memory Types for Python

Table of Contents

• mtypes
  • Table of Contents
  • Abstract
  • Use Cases
  • Current Status
  • Roadmap

Abstract

mtypes aims to tie Python's type system to other C level type hierarchies.

It provide two critical things that are useful for C extension types in Python:

• Easy marshalling of python types between Python and C.
• A universal mechanism for easily calling out to C code from Python.

mtypes does not aim to be another monolithic Python-to-C library, instead it focuses on extending the Python type system to make wrapping C libraries easier. It aims to do this by making it possible to associate C information with a type, and C information with objects, in addition to mechanisms that allow calling out to C natively from Python (the __cdict__ protocol).

Use Cases

mtypes intends to let objects work seamlessly between C and Python, meaning that there are several use cases. Common ones include:

• Wrapping numerical libraries.
  • So it could be of use to NumPy, PyTorch, Tensorflow, etc.
• Wrapping C utility libraries or device libraries.
  • So it can can be used to, for example, wrap common CUDA calls.
• Application Migration
  • So you can wrap existing applications or libraries, and give them an easy Python API.

Since C has a well-defined ABI, you can wrap any kind of library that's compatible with the C ABI. Examples include Fortran numerical libraries, C++ libraries that have a C-compatible API, and more.

Current Status

Currently, mtypes can marshall a single C long to and from C, more to come.

Roadmap

• Specify API interface
  • Specify struct API.
  • Specify __cdict__ API.
• Build out the __cdict__ protocol.
  • Build out basic structure.
  • Build out the box and unbox methods.
  • Build out implementation-selection mechanism.
  • Build out marshalling for more complex types
  • Documentation