CODEWITHSUNDEEP
python-3.xgocgo
D3XT3R
D3XT3R

Reputation: 171

convert []string from Go to python list

I am trying to return []string from golang to list in my python program. I am successfully able to convert go slice into c array from some of the references from stackoverflow.

Reference

But I am not sure on how to convert back into python list.

Any pointers would be appreciated.

Thanks.

Here are my code examples.

// example.go

package main

import "C"

import (
    "unsafe"
)

//export Example
func Example() **C.char {
    // len of slice may be dynamic
    data := []string {
        "A",
        "B",
        "C",
    }

    cArray := C.malloc(C.size_t(len(data)) * C.size_t(unsafe.Sizeof(uintptr(0))))

    a := (*[1<<30 - 1]*C.char)(cArray)

    for i, value := range data {
        a[i] = C.CString(value)
    }

    return (**C.char)(cArray)
}

func main() {}

# example.py
from ctypes import *

lib = cdll.LoadLibrary('./example.so')

lib.Example.argtypes = None
lib.Example.restype = POINTER(c_char_p)
ret_value = lib.Example()

mylist = [value for value in ret_value.contents]
print(mylist)

Upvotes: 1

Views: 407

Answers (1)

TCS
TCS

Reputation: 5910

You can do that with MetaFFI

Assume this SplitStrings.go

func SplitStringByComma(input string) []string {
    return strings.Split(input, ",")
}

use MetaFFI compiler to compile to a shared object (.so or .dll): metaffi -c --idl SplitStrings.go -g

This creates SplitStrings_MetaFFIGuest.[so/.dll]

Next, in Python, load the shared object and load the function:

import metaffi # get metaffi-api package from PIP

# load Go runtime plugin
runtime = metaffi.metaffi_runtime.MetaFFIRuntime('go')
runtime.load_runtime_plugin()

# load module
split_module = runtime.load_module('SplitStrings_MetaFFIGuest.so')

# load function

# define return type, you don't have to predefine the dimensions, but it can improve performance.
ret_type = [metaffi.metaffi_types.metaffi_type_info(metaffi.metaffi_types.MetaFFITypes.metaffi_string8_array_type, dims=1)]

# define parameters type
params_type = [metaffi.metaffi_types.metaffi_type_info(metaffi.metaffi_types.MetaFFITypes.metaffi_string8_type)]
        
# load the function
split_strings_by_comma = split_module.load_entity('callable=SplitStringByComma', params_type, ret_type)

# use it
res = split_strings_by_comma('one,two,three')

Disclaimer: I am the author of MetaFFI

Upvotes: 0

Related Questions