如何将值从 Pyqt5 GUI 传递给多个进程

Question

I have the following code:

from PyQt5 import uic, QtWidgets
import os
import sys
import threading
from multiprocessing import Pool

def fetchdata(num):
    message = window.lineEdit()
    print(message)

def processchain():
    p=Pool(processes=15)
    data=p.map(fetchdata,range(1,1000))

def alltask():
    x = threading.Thread(target=processchain)
    x.start()

if __name__ == '__main__':

    y = os.getcwd()

    app=QtWidgets.QApplication(sys.argv)
    window = uic.loadUi(os.path.normpath(y)+ "\\" + "estate.ui")
    window.pushButton.clicked.connect(alltask)

    window.show()



    sys.exit(app.exec_())

The fetchdata function being multiprocessed has a line input = window.lineEdit.text() which gives an error saying the window variable isnt defined. Does it mean I have to pass the window variable to the thread in the alltask function then pass it from the thread to the processchain function which then passes it on to all the multiprocesses? Seems like a pain and am hoping there is an easier way

How I can have the GUI objects available to every thread and process? Below is the code for reproducing the estate.ui file:

<?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0">
 <class>MainWindow</class>
 <widget class="QMainWindow" name="MainWindow">
  <property name="geometry">
   <rect>
    <x>0</x>
    <y>0</y>
    <width>640</width>
    <height>186</height>
   </rect>
  </property>
  <property name="windowTitle">
   <string>MainWindow</string>
  </property>
  <widget class="QWidget" name="centralwidget">
   <widget class="QPushButton" name="pushButton">
    <property name="geometry">
     <rect>
      <x>370</x>
      <y>30</y>
      <width>151</width>
      <height>71</height>
     </rect>
    </property>
    <property name="text">
     <string>ENTER</string>
    </property>
   </widget>
   <widget class="QLineEdit" name="lineEdit">
    <property name="geometry">
     <rect>
      <x>120</x>
      <y>49</y>
      <width>191</width>
      <height>31</height>
     </rect>
    </property>
   </widget>
   <widget class="QLabel" name="label">
    <property name="geometry">
     <rect>
      <x>40</x>
      <y>60</y>
      <width>47</width>
      <height>13</height>
     </rect>
    </property>
    <property name="text">
     <string>INPUT</string>
    </property>
   </widget>
  </widget>
  <widget class="QMenuBar" name="menubar">
   <property name="geometry">
    <rect>
     <x>0</x>
     <y>0</y>
     <width>640</width>
     <height>21</height>
    </rect>
   </property>
  </widget>
  <widget class="QStatusBar" name="statusbar"/>
 </widget>
 <resources/>
 <connections/>
</ui>

Answer 1

The GUI should not be accessed from another thread or other process, what should be done is to send the text information at the time of starting the thread and the processes:

from multiprocessing import Pool
import os
import sys
import threading

from PyQt5 import uic, QtWidgets


def fetchdata(value):
    num, message = value
    print(num, message)
    return True


def processchain(message):
    p = Pool(processes=15)
    data = p.map(fetchdata, [(i, message) for i in range(1, 1000)])
    print("results:", data)


def alltask(message):
    threading.Thread(target=processchain, args=(message,), daemon=True).start()


if __name__ == "__main__":

    app = QtWidgets.QApplication(sys.argv)
    ui_filename = os.path.join(os.path.dirname(os.path.realpath(__file__)), "estate.ui")
    window = uic.loadUi(ui_filename)

    def on_clicked():
        message = window.lineEdit.text()
        alltask(message)

    window.pushButton.clicked.connect(on_clicked)
    window.show()

    sys.exit(app.exec_())