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pocketpy: portable python 3.x interpreter

pkpy is a lightweight(~15K LOC) Python 3.x interpreter for game scripting, written in C11.

It aims to be an alternative to lua for game scripting, with elegant syntax, powerful features and competitive performance. pkpy is extremely easy to embed via a single header file pocketpy.h, without external dependencies.

Please see https://pocketpy.dev for details and try the following resources.

Live Python Demo: Run Python code in your browser

Supported Platforms

pkpy should work on any platform with a C11 compiler. These platforms are officially tested.

Windows 64-bit
Linux 64-bit / 32-bit
macOS 64-bit
Android 64-bit / 32-bit
iOS 64-bit
Emscripten 32-bit
Raspberry Pi OS 64-bit

Quick Start

You have two options to integrate pkpy into your project.

Use the single header file

Download the pocketpy.h and pocketpy.c on our GitHub Release page. And #include it in your project.

Use CMake

Clone the whole repository as a submodule into your project, In your CMakelists.txt, add the following lines:

add_subdirectory(pocketpy)
target_link_libraries(<your_target> pocketpy)

See CMakeLists.txt for details.

It is safe to use main branch in production if CI badge is green.

Compile Flags

To compile it with your project, these flags must be set:

--std=c11 flag must be set
For MSVC, /utf-8 flag must be set
NDEBUG macro should be defined for release build, or you will get poor performance

For amalgamated build, run python amalgamate.py to generate pocketpy.c and pocketpy.h in amalgamated/ directory.

Example

#include "pocketpy.h"
#include <stdio.h>

static bool int_add(int argc, py_Ref argv) {
    PY_CHECK_ARGC(2);
    PY_CHECK_ARG_TYPE(0, tp_int);
    PY_CHECK_ARG_TYPE(1, tp_int);
    py_i64 a = py_toint(py_arg(0));
    py_i64 b = py_toint(py_arg(1));
    py_newint(py_retval(), a + b);
    return true;
}

int main() {
    // Initialize pocketpy
    py_initialize();

    // Hello world!
    bool ok = py_exec("print('Hello world!')", "<string>", EXEC_MODE, NULL);
    if(!ok) goto __ERROR;

    // Create a list: [1, 2, 3]
    py_Ref r0 = py_getreg(0);
    py_newlistn(r0, 3);
    py_newint(py_list_getitem(r0, 0), 1);
    py_newint(py_list_getitem(r0, 1), 2);
    py_newint(py_list_getitem(r0, 2), 3);

    // Eval the sum of the list
    py_Ref f_sum = py_getbuiltin(py_name("sum"));
    py_push(f_sum);
    py_pushnil();
    py_push(r0);
    ok = py_vectorcall(1, 0);
    if(!ok) goto __ERROR;

    printf("Sum of the list: %d\n", (int)py_toint(py_retval()));  // 6

    // Bind native `int_add` as a global variable
    py_newnativefunc(r0, int_add);
    py_setglobal(py_name("add"), r0);

    // Call `add` in python
    ok = py_exec("add(3, 7)", "<string>", EVAL_MODE, NULL);
    if(!ok) goto __ERROR;

    py_i64 res = py_toint(py_retval());
    printf("Sum of 2 variables: %d\n", (int)res);  // 10

    py_finalize();
    return 0;

__ERROR:
    py_printexc();
    py_finalize();
    return 1;
}

Features

Name	Example	Supported
If Else	`if..else..elif`	✅
Loop	`for/while/break/continue`	✅
Function	`def f(x,*args,y=1):`	✅
Subclass	`class A(B):`	✅
List	`[1, 2, 'a']`	✅
ListComp	`[i for i in range(5)]`	✅
Slice	`a[1:2], a[:2], a[1:]`	✅
Tuple	`(1, 2, 'a')`	✅
Dict	`{'a': 1, 'b': 2}`	✅
F-String	`f'value is {x}'`	✅
Unpacking	`a, b = 1, 2`	✅
Star Unpacking	`a, *b = [1, 2, 3]`	✅
Exception	`raise/try..catch..finally`	✅
Dynamic Code	`eval()/exec()`	✅
Reflection	`hasattr()/getattr()/setattr()`	✅
Import	`import/from..import`	✅
Context Block	`with <expr> as <id>:`	✅
Type Annotation	`def f(a:int, b:float=1)`	✅
Generator	`yield i`	✅
Decorator	`@cache`	✅

Performance

Currently, pkpy is as fast as cpython 3.9. Performance results for cpython 3.9 are applicable to for pkpy.

See https://pocketpy.dev/performance/ for details.

And these are the results of the primes benchmark on Intel i5-12400F, WSL (Ubuntu 20.04 LTS), which roughly reflects the performance among c++, lua, pkpy and cpython.

name	version	time	file
c++	gnu++11	`0.104s ■□□□□□□□□□□□□□□□`	benchmarks/primes.cpp
lua	5.3.3	`1.576s ■■■■■■■■■□□□□□□□`	benchmarks/primes.lua
pkpy	1.2.7	`2.385s ■■■■■■■■■■■■■□□□`	benchmarks/primes.py
cpython	3.8.10	`2.871s ■■■■■■■■■■■■■■■■`	benchmarks/primes.py

Used By

	Description
TIC-80	TIC-80 is a fantasy computer for making, playing and sharing tiny games.
py-js	Python3 externals for Max / MSP.
crescent	Crescent is a cross-platform 2D fighting and beat-em-up game engine.
orxpy	Python extension for orx engine.
CANopenTerm	Open-source software tool for CANopen CC networks and devices.

Submit a pull request to add your project here.

Contribution

All kinds of contributions are welcome.

Submit a Pull Request
- fix a bug
- add a new feature
Open an Issue
- any suggestions
- any questions

If you find pkpy useful, consider star this repository (●'◡'●)

Sponsor this project

You can sponsor this project via these ways.

Your sponsorship will help us develop pkpy continuously.

Reference

cpython

The official implementation of Python programming language.
byterun

An excellent learning material. It illustrates how Python's virtual machine works.

Star History

License

MIT License