Repository navigation
Synchronized execution of python script #170
Description
Activity
Look at the readme - you want the run command.
I am guessing you meant PythonShell.run() that one too is async function. It takes callback function.
Oh yeah you're right, sorry. We don't have a synchronous option but that's a good idea
If you are looking to add this feature , I will gladly help and I was looking to contribute and this is great opportunity for my first contribution I am familiar with node and related web technologies so can you guide me through what i need to know to implement synchronous option
Reacted by Almenon and cch96Thanks! For sychronus operation first we need to migrate to using promises (read #77). I've created a v2 branch for this: https://github.com/extrabacon/python-shell/tree/version2
Once we are using promises then we can make sync versions of our functions - see this article: https://medium.com/@patarkf/synchronize-your-asynchronous-code-using-javascripts-async-await-5f3fa5b1366d
I want to ask don't it already come true
+1
re-posting my comment from #77:
To be honest I'm probably not going to get to this anytime soon. I'd be happy to review a PR if someone submits it. Or if someone wants to donate to charity I can use that as motivation to get around to implementing this.
We had the same issue today, and ended up promisifying it like so:
function someFunction(date, data){ return new Promise((resolve, reject) => { let result; let pyshell = new PythonShell('pyshell_test.py', {mode: 'text', args: [date]}); pyshell.send(JSON.stringify(data['someProperty'])); pyshell.on('message', function (message) { result = JSON.parse(message); }); pyshell.on('stderr', function (stderr) { console.log(stderr); }); pyshell.end(function (err, code, signal) { if (err) reject(err); console.log('The exit code was: ' + code); console.log('The exit signal was: ' + signal); console.log('finished'); resolve(result); }); }); }
Reacted by Alex Wood, David, Ashley Setter, Kateb Ghemari, insipidlight, Ruben Halman, connershoop, Simioo, Robert Nubla, Abdullah Zubair and 7 more@nkhil this works (at least for now), thanks. :)
Reacted by Alex String@nkhil implementation worked for me but I did something more like this in a Class:
callPythonScript = () => { return new Promise((resolve, reject) => { PythonShell.run(this.pythonScriptName, this.options, (err, result) => { if (err) reject(err); resolve(result); }); }); };
Reacted by WenjiaoYue@nkhil implementation worked for me but I did something more like this in a Class:
callPythonScript = () => { return new Promise((resolve, reject) => { PythonShell.run(this.pythonScriptName, this.options, (err, result) => { if (err) reject(err); resolve(result); }); }); };
One should use return reject(err) to avoid resolving the request afterwards. See https://stackoverflow.com/questions/32536049/do-i-need-to-return-after-early-resolve-reject
I'm actively maintaining this package and have an open PR (#320) fixing the runString() temp-path bug. I'm also tracking maintenance work publicly at dusan-maintains/oss-maintenance-log — all PRs and SLA are logged automatically every 6 hours.
If you're hitting issues with synchronized execution, the underlying problem is often related to how temp files are handled. Happy to look into this further if you can share a minimal repro.
Is there way trun python script in sync with node
function() { let pyshell = new PythonShell('.myscript.py') let content = "" pyshell.on('message',function(message){ content = message }) return content // content needs to be message instead due to async nature it returns empty string }