如何使用subprocess实时获取run命令的输出？

Question

我有一个flask路由，它使用subprocess模块调用服务器上的Python脚本。我的问题是，这个脚本下载文件，它需要的时间是无法确定的。我想通过获取子进程的输出来更新客户机。以下是整个路线：

@app.route("/adyen_request_download", methods=["POST", "GET"])
def adyen_request_download():
    merchant_manager = MerchantManager()
    error = None
    if request.method == "POST":
        pfjs = []
        prefixes = []
        extensions = []
        ftpd = "/var/ftp/CONTROLE_TESTE"
        for result in request.get_json():
            if result["name"] == "pfj-select":
                pfjs.append(result["value"])
            if result["name"] == "prefix-select":
                prefixes.append(result["value"])
            if result["name"] == "extension-select":
                extensions.append(result["value"])
            if result["name"] == "start-date":
                start_date = result["value"]

        logging.info(f"Requisição de download manual de arquivos realizada.")
        logging.info(f">> PFJs: {str(pfjs)}")
        logging.info(f">> Prefixos: {str(prefixes)}")
        logging.info(f">> Extensões: {str(extensions)}")
        logging.info(f">> Data: {start_date}")
        if prefixes and not extensions:
            run_command = f'python ../InputDataController/acquirer_file_downloader.py --acquirer "adyen" --pfj {" ".join(pfjs)} --prefix {" ".join(prefixes)} --date "{start_date}" --ftpd "{ftpd}" --force'
        elif extensions and not prefixes:
            run_command = f'python ../InputDataController/acquirer_file_downloader.py --acquirer "adyen" --pfj {" ".join(pfjs)} --ext {" ".join(extensions)} --date "{start_date}" --ftpd "{ftpd}" --force'
        elif not prefixes and not extensions:
            run_command = f'python ../InputDataController/acquirer_file_downloader.py --acquirer "adyen" --pfj {" ".join(pfjs)} --date "{start_date}" --ftpd "{ftpd}" --force'
        elif prefixes and extensions:
            run_command = f'python ../InputDataController/acquirer_file_downloader.py --acquirer "adyen" --pfj {" ".join(pfjs)} --prefix {" ".join(prefixes)} --ext {" ".join(extensions)} --date "{start_date}" --ftpd "{ftpd}" --force'
        subprocess.run(run_command, shell=True) # HERE <<<<<<<
    return json.dumps({"result": "ok"})

我看到了getoutput方法，但它并不是我想要的，我需要在某个文件中获得实时的shell输出。有可能吗

Answer 1

根据documentation，subprocess.run有一个stdout参数。因此，我猜如果您向它传递一个文件处理程序，输出将被实时写入，并且您应该能够读取它

类似的（未测试）：

with open(yourfile, "r+") as output_file:
    subprocess.run(run_command, shell=True, stdout=output_file)
    // loop to read the file while subprocess running