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PocketPy is a lightweight(~5000 LOC) Python interpreter for game engines.

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It is extremely easy to embed. Including a compiler, optimizer and bytecode virtual machine. All of them are available in a single header file pocketpy.h, without external dependencies.

Please see https://pocketpy.dev for details or try Live Demo.

sample_img

Features

Name Example Supported
If Else if..else..elif YES
Loop for/while/break/continue YES
Function def f(x,*args,y=1): YES
Subclass class A(B): YES
List [1, 2, 'a'] YES
ListComp [i for i in range(5)] YES
Slice a[1:2], a[:2], a[1:] YES
Tuple (1, 2, 'a') YES
Dict {'a': 1, 'b': 2} YES
F-String f'value is {x}' YES
Unpacking a, b = 1, 2 YES
Star Unpacking a, *b = [1, 2, 3] NO
Exception raise/try..catch YES
Dynamic Code eval()/exec() YES
Reflection hasattr()/getattr()/setattr() YES
Import import/from..import YES
Context Block with as : YES
Type Annotation def f(a: int, b : float = 1) YES

Getting Started

C/C++

For C/C++ developers, you can download the pocketpy.h on our GitHub release page.

https://github.com/blueloveTH/pocketpy/releases/latest

Check C-API for references. For further customization, you can use C++ API.

#include "pocketpy.h"

int main(){
    // Create a virtual machine
    VM* vm = pkpy_new_vm(true);
    
    // Hello world!
    pkpy_vm_exec(vm, "print('Hello world!')");

    // Create a list
    pkpy_vm_exec(vm, "a = [1, 2, 3]");

    // Eval the sum of the list
    char* result = pkpy_vm_eval(vm, "sum(a)");
    printf("%s", result);   // 6

    // Free the resources
    pkpy_delete(result);
    pkpy_delete(vm);
    return 0;
}

Unity Engine

PocketPy for Unity can be installed via Unity Asset Store.

https://assetstore.unity.com/packages/slug/241120

x+1);
Debug.Log(vm.eval(“test(3.14)”)); // ‘4.14’
}
}” dir=”auto”>

using UnityEngine;

public class Test01 : MonoBehaviour
{
    // Start is called before the first frame update
    void Start()
    {
        // Create a virtual machine
        pkpy.VM vm = new pkpy.VM();

        // Create a list
        vm.exec("a = [1, 2, 3]");

        // Eval the sum of the list
        string result = vm.eval("sum(a)");
        Debug.Log(result);   // 6

        // Print to the standard output
        vm.exec("print(a)");
        pkpy.PyOutput o = vm.read_output();
        Debug.Log(o.stdout); // [1, 2, 3]

        // Create a binding
        vm.bind("builtins", "test", (double x) => x+1);  
        Debug.Log(vm.eval("test(3.14)")); // '4.14'
    }
}

Flutter

Run the following script to install this plugin.

See https://pocketpy.dev/getting-started/flutter/

Pre-compiled Libs

You can download artifact.zip from Github Release page. In this archive, there are pre-compiled libraries for many platforms. The file structure is as follows.

- android/
  - arm64-v8a/
    - libpocketpy.so
  - armeabi-v7a/
    - libpocketpy.so
  - x86_64/
    - libpocketpy.so
- linux/
  - x86_64/
    - pocketpy
    - pocketpy.so
- macos/
  - pocketpy.bundle/
- web/
  - lib/
    - pocketpy.js
    - pocketpy.wasm
- windows/
  - x86_64/
    - pocketpy.dll
    - pocketpy.exe

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

Reference

  • cpython

    The official implementation of Python programming language.

  • byterun

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

  • emhash

    A very fast and memory efficient c++ flat hash map/set. In our test case, it is 40% faster than std::unordered_map.

License

PocketPy is licensed under the MIT License.

PocketPy uses emhash(MIT License) to implement Python’s internal __dict__ object.

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