Node.JS Pyshell在向Python发送第二条消息时崩溃，[ERR\u STREAM\u WRITE\u AFTER\u END]：WRITE AFTER END

Question

我有一个Node.JS服务器，它使用Pyshell.send向Python脚本发送消息

当Pyshell使用print Node.JS返回消息时，将使用Pyshell.on接收该消息，然后读取返回的消息

当再次使用第二条消息执行此操作时，它会崩溃，并出现以下错误：

Error [ERR_STREAM_WRITE_AFTER_END]: write after end
    at writeAfterEnd (_stream_writable.js:243:12)
    at Socket.Writable.write (_stream_writable.js:291:5)
    at PythonShell.send (/Users/maxkenney/Desktop/nodeLanguageProcessing/node_modules/python-shell/index.js:285:20)
    at Namespace.<anonymous> (/Users/maxkenney/Desktop/nodeLanguageProcessing/app.js:87:10)
    at Namespace.emit (events.js:189:13)
    at Namespace.emit (/Users/maxkenney/Desktop/nodeLanguageProcessing/node_modules/socket.io/lib/namespace.js:213:10)
    at /Users/maxkenney/Desktop/nodeLanguageProcessing/node_modules/socket.io/lib/namespace.js:181:14
    at process._tickCallback (internal/process/next_tick.js:61:11)
Emitted 'error' event at:
    at writeAfterEnd (_stream_writable.js:245:10)
    at Socket.Writable.write (_stream_writable.js:291:5)
    [... lines matching original stack trace ...]
    at process._tickCallback (internal/process/next_tick.js:61:11)

我相信这可能是因为Python外壳在一条消息后关闭了，但我不确定。任何帮助都将不胜感激

Node.JS脚本（相关部分）

let pyshell = new PythonShell('my_script.py');



pyshell.on('message', function(message){
    console.log("python said: " + message);
});

pyshell.send("This is a test entry").end(function(err){
        if(err) handleError(err);
});

最后一个pyshell.send稍后会重复，并崩溃

Python脚本：

import sys
import spacy
import nltk

nlp = spacy.load("en_core_web_sm");

def convertGeneratorObjectToListOfString(generatorObject):
    list = []

    for item in generatorObject:
        list.append(str(item))

    return list

def main():


    #doc = nlp(sys.argv[1])
    doc = nlp(sys.stdin.readline())

    # Return the printed message to Node
    jsonObjectToReturn = {}

    for token in doc:
        dependents = token.children
        listOfChildrenTag = []

        for d in dependents:
            listOfChildrenTag.append(d.dep_)
        jsonObjectToReturn[token.text] = {
            "text": token.text,
            "lemma": token.lemma_,
            "tag": token.tag_,
            "dep": token.dep_,
            "dependencies": convertGeneratorObjectToListOfString(token.children),
            "dependenciesTag": listOfChildrenTag
        }

    print(jsonObjectToReturn)


if __name__ == '__main__':
    main()

我在这里包含了所有的python代码，因为我不确定，但我相信这个问题也可能是因为python脚本在主脚本完成后关闭。抱歉，我不熟悉运行常量python脚本

Answer 1

当您调用.end()时，您将关闭该流，使其无法再使用。因此，在处理完流之前不要调用.end()。您可以调用.send()，而无需调用.end()

如果还需要监视python脚本何时结束，则可以使用pyshell对象的childProcess属性

let pyshell = new PythonShell('my_script.py');
pyshell.childProcess.on('exit', (code) => {
    console.log(`python program ended with exit code: ${code}`);
});