PyGo [WIP] / [POC]

A small library exposing a helper decorator to ease the call of a go shared library from python.

Installation

python setup.py install

Get started

How to call go from python with this lib:

edit your go lib `mygolib.go`:

package main

// #include <stdlib.h>
import "C"

import (
	"fmt"
    "unsafe"
)

//export myGoFunc
func myGoFunc(carg *C.char) *C.char {
	goarg := C.GoString(carg)
	return C.CString(fmt.Sprintf("hello %s", goarg))
}

//export freeMem
func freeMem(c *C.void) {
	C.free(unsafe.Pointer(c))
}


func main() {}

, build it:

$ go build -o ./mygolib.so -buildmode=c-shared mygolib.go

, use it

edit your main.py

import pygo

@pygo.gofunc(lib="mygolib.so")
def myGoFunc(string_1, *string): pass

@pygo.gofunc(lib="mygolib.so", sig="string,string", fname="myGoFunc")
def test1(): pass

@gofunc(lib="tests/mygolib.so", fname="myGoFunc")
def test2(c_char_p_1, *c_char_p): pass


if __name__ == '__main__':
    res = myGoFunc("world")
    print( res))
    
    res = test1("world")
    print( res))

    res = test2("world".encode('utf-8'))
    print( res.decode('utf-8'))

, run it

$ python3 main.py
hello world
hello world
hello world

Go Generation !

There's also a go binary tool named pygo which you can use to generate everything.

Look at ./tests/mylibgo/mygolib.go.

it contains a //go:generate pygo, and some funcs have a @pygo.export annotation. All exported funcs (with an upper capital) which have been annotated will be:

exported in a small library generated in the mypkg/mylib/pygo path,
along with the corresponding .so file,
and a mypkg/mylib/pygo/mylib.py python file that you can import from any python package

From:

/* this func is exported
 * @pygo.export
 */
func Test0() {
	return
}

//@pygo.export
func Test1(arg string) {
	return
}

//@pygo.export
func Test2(arg string) int {
	return 0
}

You run:

PYGO_LOG=INFO go generate -v ./...

And you get:

// Code generated by go generate; DO NOT EDIT.
// This file was generated by pygo at
// 2021-11-24 20:04:28.322044945 +0000 UTC m=+0.003300657
package main

import (
   "C"
   "github.com/yanndegat/pygo/tests/mylibgo"
)

//export Test0
func Test0()  {
    mygolib.Test0()
}

//export Test1
func Test1(arg *C.char)  {
    mygolib.Test1(C.GoString(arg))
}

//export Test2
func Test2(arg *C.char) int {
   return mygolib.Test2(C.GoString(arg))
}

And

# Code generated by go generate; DO NOT EDIT.
# This file was generated by pygo at
# 2021-11-24 20:04:28.322456268 +0000 UTC m=+0.003711937
from pygo import gofunc


@gofunc(lib="_mygolib.so")
def Test0(): pass


@gofunc(lib="_mygolib.so")
def Test1(string_0): pass


@gofunc(lib="_mygolib.so")
def Test2(string_0, *int): pass

Motivation

Hopefully, this lib could help one convert a python codebase to go incrementally.

yanndegat/pygo