Node failed to call python3 subprocess

  node.js, question
var fs = require('fs'),
    stdin = process.stdin,
    stdout = process.stdout,
    spawn = require("child_process").spawn;
var path= require('path');
//限制访问路径,及权限
var userdir= '/Users/FusGoethe/Desktop';
//process.cwd() 返回当前文件夹路经
var args = process.argv.slice(2),
    filePath = args[0],
    pyPath =path.join(userdir,args[1]);

var pathname = path.join(userdir,filePath);
var datas = [],
    accounts = 0,
    lock = true;




/**
 * 读取文件
 * @param dir        目标文件夹路径
 * @param callback
 */
function readFiles(dir,callback){


    fs.readdir(dir,function(err,files){

        if(!files){
            stdout.write('your path is wrong\n');
            return;
        }

        accounts = files.length;

        files.forEach(function(file){


            if(file.indexOf('.') === -1 || file[0] == '.'){
                accounts--;
                return;
            }

            console.log(file);

            //得到文件路径
            var pathname = path.join(dir,file);

            fs.readFile(pathname,'utf-8', function (err, data) {
                if (err) throw err;

                console.log(1);

                callback(data);
            });

        });

    });

    stdout.write('Please wait...\n');
}


function startChild(data){



    datas.push(data);

    if(!(--accounts) && lock ){
        lock = false;

        datas.join("#NODEJS#");

       var child = spawn('python3',[pyPath,datas]);

        console.log(2);

        child.stdout.setEncoding('utf-8');

        child.stdout.on("data",function(data){
            console.log(data);
        }).on("end",function(){
            console.log("stdoutOver");
        });

        child.on("err",function(err){
            console.log(err);
        }).on("exit",function(){
            console.log("\n\nover!");
        });

    }
}


readFiles(pathname,startChild);

The above is js code


import sys data = sys.argv[1] string=data.split("#NODEJS#").join("#PYTHON3#"); print(string) fh = open('./dat/ex.dat','w',encoding='utf-8') fh.write(string)

The above is py code

$ node ex.js ./work/py ./work/py/nodepy.py
 Please wait  ...
 exforfoundmantal.py
 generate_usernames.py
 kk.html
 nodepy.py
 statistics.py
 one
 one
 one
 one
 one
 2
 stdoutOver
 
 
 over!

The above is the output

There has been no change in the documents either.

Sorry, it has been resolved. I have confused the syntax of python3 and js