I try to get logs from multiprocessing work and show them on GUI.
Based on this document
gui.py:
from PyQt5 import QtCore, QtWidgets
import logging
from log_test import main
Signal = QtCore.pyqtSignal
Slot = QtCore.pyqtSlot
class Signaller(QtCore.QObject):
signal = Signal(str, logging.LogRecord)
class QtHandler(logging.Handler):
def __init__(self, slotfunc, *args, **kwargs):
super().__init__(*args, **kwargs)
self.signaller = Signaller()
self.signaller.signal.connect(slotfunc)
def emit(self, record):
s = self.format(record)
self.signaller.signal.emit(s, record)
class Worker(QtCore.QObject):
finished = Signal()
#Slot()
def start(self):
main()
self.finished.emit()
class Ui_Dialog(QtCore.QObject):
def __init__(self):
super().__init__()
def setupUi(self, Dialog):
Dialog.setObjectName("Dialog")
Dialog.setEnabled(True)
Dialog.resize(530, 440)
self.verticalLayout = QtWidgets.QVBoxLayout(Dialog)
self.verticalLayout.setObjectName("verticalLayout")
self.button = QtWidgets.QPushButton(Dialog)
self.button.setText("start working")
self.verticalLayout.addWidget(self.button)
self.logWidget = QtWidgets.QPlainTextEdit(Dialog)
self.logWidget.setReadOnly(True)
self.verticalLayout.addWidget(self.logWidget)
self.handler = QtHandler(self.update_log_gui)
logging.getLogger('log').addHandler(self.handler)
self.button.clicked.connect(self.start_work)
#Slot(str, logging.LogRecord)
def update_log_gui(self, status, record):
self.logWidget.appendPlainText(status)
def config_thread(self):
self.worker_thread = QtCore.QThread()
self.worker_thread.setObjectName('WorkerThread')
self.worker = Worker()
self.worker.moveToThread(self.worker_thread)
self.worker_thread.started.connect(self.worker.start)
self.worker.finished.connect(self.worker_thread.quit)
self.worker.finished.connect(self.worker.deleteLater)
self.worker_thread.finished.connect(self.worker_thread.deleteLater)
self.worker_thread.finished.connect(lambda: self.button.setEnabled(True))
pass
def start_work(self):
self.config_thread()
self.worker_thread.start()
self.button.setEnabled(False)
if __name__ == "__main__":
import sys
QtCore.QThread.currentThread().setObjectName('MainThread')
app = QtWidgets.QApplication(sys.argv)
Dialog = QtWidgets.QDialog()
ui = Ui_Dialog()
ui.setupUi(Dialog)
Dialog.show()
sys.exit(app.exec_())
log_test.py (where multiprocessing work happens)
import logging
import time
from multiprocessing import Pool
def f(name):
logger = logging.getLogger('log.' + name)
logger.error('hello there 1')
time.sleep(0.5)
logger.error('hello there 2')
time.sleep(0.5)
logger.error('hello there 3')
time.sleep(0.5)
def main():
with Pool(5) as p:
p.map(f, ['aaa', 'bbb', 'ccc'])
At first time, I thought working in single thread causing the problem. So I added QThread to this.
Later I discovered in debug, it seems to QtHandler.emit() works fine at receiving log messages. But the connected slot function, update_log_gui() does not work somehow.
I solved it myself.
#Alexander was right. Indeed my QtHandler has a problem when multiprocessing but I don't know exactly why. Rather, you wanna implement QueueHandler. An example in this article (Written in Korean) helped me.
from PyQt5 import QtCore, QtWidgets
import logging
import multiprocessing
from log_test import main
Signal = QtCore.pyqtSignal
Slot = QtCore.pyqtSlot
QThread = QtCore.QThread
class Signaller(QtCore.QObject):
signal = Signal(logging.LogRecord)
class Worker(QtCore.QObject):
finished = Signal()
def __init__(self, q):
super().__init__()
self.q = q
#Slot()
def start(self):
main(self.q)
self.finished.emit()
class Consumer(QThread):
popped = Signaller()
def __init__(self, q):
super().__init__()
self.q = q
self.setObjectName('ConsumerThread')
def run(self):
while True:
if not self.q.empty():
record = self.q.get()
self.popped.signal.emit(record)
class Ui_Dialog(QtCore.QObject):
def __init__(self, app):
super().__init__()
self.app = app
def setupUi(self, Dialog):
Dialog.setObjectName("Dialog")
Dialog.setEnabled(True)
Dialog.resize(530, 440)
self.verticalLayout = QtWidgets.QVBoxLayout(Dialog)
self.verticalLayout.setObjectName("verticalLayout")
self.button = QtWidgets.QPushButton(Dialog)
self.button.setText("start working")
self.verticalLayout.addWidget(self.button)
self.logWidget = QtWidgets.QPlainTextEdit(Dialog)
self.logWidget.setReadOnly(True)
self.verticalLayout.addWidget(self.logWidget)
self.button.clicked.connect(self.start_work)
self.q = multiprocessing.Manager().Queue()
self.consumer = Consumer(self.q)
self.consumer.popped.signal.connect(self.update_log_gui)
self.consumer.start()
app.aboutToQuit.connect(self.shutdown_consumer)
#Slot(logging.LogRecord)
def update_log_gui(self, record):
self.logWidget.appendPlainText(str(record.msg))
def config_thread(self):
self.worker_thread = QtCore.QThread()
self.worker_thread.setObjectName('WorkerThread')
self.worker = Worker(self.q)
self.worker.moveToThread(self.worker_thread)
self.worker_thread.started.connect(self.worker.start)
self.worker.finished.connect(self.worker_thread.quit)
self.worker.finished.connect(self.worker.deleteLater)
self.worker_thread.finished.connect(self.worker_thread.deleteLater)
self.worker_thread.finished.connect(lambda: self.button.setEnabled(True))
def start_work(self):
self.config_thread()
self.worker_thread.start()
self.button.setEnabled(False)
def shutdown_consumer(self):
if self.consumer.isRunning():
self.consumer.requestInterruption()
self.consumer.quit()
self.consumer.wait()
if __name__ == "__main__":
import sys
QtCore.QThread.currentThread().setObjectName('MainThread')
app = QtWidgets.QApplication(sys.argv)
Dialog = QtWidgets.QDialog()
ui = Ui_Dialog(app)
ui.setupUi(Dialog)
Dialog.show()
sys.exit(app.exec_())
Related
button of class Main don't connect with class Qcombobox of Signals
from PyQt5.QtCore import QObject, pyqtSignal
from PyQt5.QtWidgets import *
import sys
from PyQt5 import QtGui
class Signals(QWidget):
asignal = pyqtSignal(str)
def __init__(self):
super(Signals, self).__init__()
self.setGeometry(300, 250, 400, 300)
self.ii()
self.show()
def ii(self):
vbox = QVBoxLayout()
self.combo = QComboBox()
self.combo.addItem("Python")
self.combo.addItem("Java")
self.combo.addItem("C++")
self.combo.addItem("C#")
self.combo.addItem("Ruby")
self.buttom = QPushButton("Click")
self.buttom.clicked.connect(self.windown2)
vbox.addWidget(self.combo)
vbox.addWidget(self.buttom)
self.setLayout(vbox)
def do_something(self):
self.asignal.emit(self.combo.currentText())
def windown2(self):
self.ggpp = Main()
self.ggpp.show()
class Main(QWidget):
def __init__(self):
super(Main, self).__init__()
self.setGeometry(500,150, 600, 300)
vbox1 = QVBoxLayout()
self.buttom1 = QPushButton("Click")
self.buttom1.clicked.connect(self.coso1)
vbox1.addWidget(self.buttom1)
self.setLayout(vbox1)
def coso1(self):
s = Signals()
s.asignal.connect(lambda sig: print("self.combo.currentText()>>>>>" + sig))
s.do_something()
if __name__ == '__main__':
app = QApplication(sys.argv)
nals = Signals()
nals.show()
sys.exit(app.exec())
What you see happens because you're not using the existing instance of Signals, but you're creating a new one each time the button is clicked.
In your case, you could add a reference to the instance as an argument when you create the new window, so that you can correctly connect to its signal.
class Signals(QWidget):
# ...
def windown2(self):
self.ggpp = Main(self)
self.ggpp.show()
class Main(QWidget):
def __init__(self, signals):
super(Main, self).__init__()
self.signals = signals
self.signals.asignal.connect(self.coso1)
self.setGeometry(500,150, 600, 300)
vbox1 = QVBoxLayout()
self.buttom1 = QPushButton("Click")
self.buttom1.clicked.connect(self.signals.do_something)
vbox1.addWidget(self.buttom1)
self.setLayout(vbox1)
def coso1(self, sig):
print("self.combo.currentText()>>>>>" + sig)
I have a GUI that implements 3 buttons
One of the buttons has the "start" function tied, which contains 2 processes, in fact, these are two cycles that should work multithreaded, but I need to add more code to the "start" function that, for example, changes some widgets.
The problem is that if I add some code after self.threadpool.start(thread2) self.threadpool.start(thread3), then it is not executed upon completion of these threads, but before that, or not at all.
I wrote a toy example that fully describes my requirements from the program
import sys
import time
from PySide2.QtCore import QThreadPool, QRunnable, Slot
from PySide2.QtWidgets import QApplication, QWidget, QPushButton
class Example(QWidget):
def __init__(self):
super().__init__()
self.initUI()
self.threadpool = QThreadPool()
self.btn.clicked.connect(lambda: self.start())
def start(self):
t1 = Worker(th1)
t2 = Worker(th2)
self.btn.setEnabled(False)
self.threadpool.start(t1)
self.threadpool.start(t2)
self.btn.setEnabled(True)
def initUI(self):
self.btn = QPushButton('Start', self)
self.btn.resize(self.btn.sizeHint())
self.btn.move(50, 50)
self.setGeometry(300, 300, 300, 200)
self.setWindowTitle('HELP')
self.show()
class Worker(QRunnable):
def __init__(self, fn):
super(Worker, self).__init__()
self.fn = fn
#Slot() # QtCore.Slot
def run(self):
self.fn()
def th1():
time.sleep(5)
print("th1")
def th2():
time.sleep(10)
print("th2")
app = QApplication(sys.argv)
ex = Example()
sys.exit(app.exec_())
I need the button to turn off before the streams start and turn on only after their completion.
The solution should be fair for any code I want to use after streams.
First, using the Slot decorator in the methods of a QRunnable is useless since it is not a QObject.
On the other hand, the idea of implementing a multithreading logic is that the main thread does not block, so you should not expect that after invoking start() it will be executed after it finishes executing the threads.
The solution is to create a QObject that emits a signal before and after the execution of the thread, and with that logic implement the GUI update:
import sys
import time
from PySide2.QtCore import QObject, QThreadPool, QRunnable, Signal, Slot
from PySide2.QtWidgets import QApplication, QWidget, QPushButton
class Example(QWidget):
def __init__(self):
super().__init__()
self.initUI()
self.active_workers = 0
self.threadpool = QThreadPool()
self.btn.clicked.connect(self.start)
#Slot()
def start(self):
t1 = Worker(th1)
t1.signaller.started.connect(self.on_started)
t1.signaller.finished.connect(self.on_finished)
t2 = Worker(th2)
t2.signaller.started.connect(self.on_started)
t2.signaller.finished.connect(self.on_finished)
self.btn.setEnabled(False)
self.threadpool.start(t1)
self.threadpool.start(t2)
def initUI(self):
self.btn = QPushButton("Start", self)
self.btn.resize(self.btn.sizeHint())
self.btn.move(50, 50)
self.setGeometry(300, 300, 300, 200)
self.setWindowTitle("HELP")
self.show()
#Slot()
def on_started(self):
self.active_workers += 1
#Slot()
def on_finished(self):
self.active_workers -= 1
self.btn.setEnabled(self.active_workers == 0)
class Signaller(QObject):
started = Signal()
finished = Signal()
class Worker(QRunnable):
def __init__(self, fn):
super(Worker, self).__init__()
self.signaller = Signaller()
self.fn = fn
def run(self):
self.signaller.started.emit()
self.fn()
self.signaller.finished.emit()
def th1():
time.sleep(5)
print("th1")
def th2():
time.sleep(10)
print("th2")
app = QApplication(sys.argv)
ex = Example()
sys.exit(app.exec_())
I'm very new to PyQt5, and I'm trying to make an interactive gui for plotting of data. However, this problem may well be completely unrelated to PyQt5 and more a problem with my understanding of object oriented programming in general.
I have a MainWindow class, a SupportClass1 and a SupportClass2. When I make an instance of SupportClass1, I want to call the method DoSomething in the MainWindow class by referring to the object window, but I get the error message NameError: name 'window' is not defined.
I have no problems creating a method in the SupportClass2 and calling that from the MainWindow class so I get the impression that I have not instantiated the MainWindow class correctly which I don't understand as I thought I had defined window as an instace of the MainWindow class.
Can anyone help me understand what is wrong in my logic and how to solve this problem?
from PyQt5 import QtWidgets, QtCore
from pyqtgraph import PlotWidget, plot
import pyqtgraph as pg
import sys
import os
from random import randint
class MainWindow(QWidget):
def __init__(self):
super().__init__()
self.graphWidget = pg.PlotWidget()
self.x = list(range(100))
self.y = [randint(0,100) for _ in range(100)]
self.graphWidget.setBackground('w')
pen = pg.mkPen(color=(255, 0, 0))
self.data_line = self.graphWidget.plot(self.x, self.y, pen=pen)
self.button = QPushButton('Test')
self.button.clicked.connect(self.InstantiateSupportClasses)
self.gui_box = QVBoxLayout()
self.gui_box.addWidget(self.graphWidget)
self.gui_box.addWidget(self.button)
self.setLayout(self.gui_box)
self.setGeometry(300, 300, 300, 150)
self.setWindowTitle('Test application')
self.show()
def InstantiateSupportClasses(self):
supp_class2 = SupportClass2()
print(supp_class2.GetVariable())
supp_class1 = SupportClass1()
def DoSomething(self):
print('I did something!')
class SupportClass1():
def __init__(self):
window.DoSomething
class SupportClass2():
def __init__(self):
self.some_variable = 5
def GetVariable(self):
return self.some_variable
def main():
app = QApplication(sys.argv)
app.setStyle('Fusion')
window = MainWindow()
sys.exit(app.exec_())
if __name__ == '__main__':
main()```
I see that you are using the "window" object from the "SupportClass1" class.
but that class does not recognize this object one solution is to insert that object to the "SupportClass1()"
from PyQt5 import QtWidgets, QtCore
from pyqtgraph import PlotWidget, plot
import pyqtgraph as pg
import sys
import os
from random import randint
class MainWindow(QWidget):
def __init__(self):
super().__init__()
self.graphWidget = pg.PlotWidget()
self.x = list(range(100))
self.y = [randint(0,100) for _ in range(100)]
self.graphWidget.setBackground('w')
pen = pg.mkPen(color=(255, 0, 0))
self.data_line = self.graphWidget.plot(self.x, self.y, pen=pen)
self.button = QPushButton('Test')
self.button.clicked.connect(self.InstantiateSupportClasses)
self.gui_box = QVBoxLayout()
self.gui_box.addWidget(self.graphWidget)
self.gui_box.addWidget(self.button)
self.setLayout(self.gui_box)
self.setGeometry(300, 300, 300, 150)
self.setWindowTitle('Test application')
self.show()
def InstantiateSupportClasses(self):
supp_class2 = SupportClass2()
print(supp_class2.GetVariable())
supp_class1 = SupportClass1(self)
def DoSomething(self):
print('I did something!')
class SupportClass1():
def __init__(self, window):
window.DoSomething()
class SupportClass2():
def __init__(self):
self.some_variable = 5
def GetVariable(self):
return self.some_variable
def main():
app = QApplication(sys.argv)
app.setStyle('Fusion')
window = MainWindow()
sys.exit(app.exec_())
if __name__ == '__main__':
main()
first, see code below:
import sys
from PyQt5.QtCore import (Qt, pyqtSignal, pyqtSlot)
from PyQt5.QtWidgets import (QWidget, QLCDNumber, QSlider,
QVBoxLayout, QApplication)
class Example(QWidget):
def __init__(self):
super().__init__()
self.initUI()
def printLabel(self, str):
print(str)
#pyqtSlot(int)
def on_sld_valueChanged(self, value):
self.lcd.display(value)
self.printLabel(value)
def initUI(self):
self.lcd = QLCDNumber(self)
self.sld = QSlider(Qt.Horizontal, self)
vbox = QVBoxLayout()
vbox.addWidget(self.lcd)
vbox.addWidget(self.sld)
self.setLayout(vbox)
self.sld.valueChanged.connect(self.on_sld_valueChanged)
self.setGeometry(300, 300, 250, 150)
self.setWindowTitle('Signal & slot')
self.show()
if __name__ == '__main__':
app = QApplication(sys.argv)
ex = Example()
sys.exit(app.exec_())
I'm a little puzzled about how the true value in sld is transmitted to the formal parameter 'value' in the slot function : def sld_valChanged(self, value).
Because i can't see something like this: self.sld.valueChanged.connect(partial(self.sld_valChanged, self.sld.value))
Could someone explain that?
I am writing a program with pyqt5 where pressing a button first cycles through some pictures then cycles through some videos.
from PyQt5.QtCore import *
from PyQt5.QtGui import *
from PyQt5.QtWidgets import *
from PyQt5.QtMultimedia import *
from PyQt5.QtMultimediaWidgets import *
import glob
import argparse
import sys
class MainWindow(QMainWindow):
def __init__(self,args):
super(MainWindow, self).__init__()
self.setWindowTitle('Navon test')
self.setWindowFlags(Qt.FramelessWindowHint)
# exit option for the menu bar File menu
self.exit = QAction('Exit', self)
self.exit.setShortcut('Ctrl+q')
# message for the status bar if mouse is over Exit
self.exit.setStatusTip('Exit program')
# newer connect style (PySide/PyQT 4.5 and higher)
self.exit.triggered.connect(app.quit)
self.setWindowIcon(QIcon('icon.ico'))
self.centralwidget = CentralWidget(args)
self.setCentralWidget(self.centralwidget)
def keyPressEvent(self, QKeyEvent):
if QKeyEvent.key() == Qt.Key_Escape:
QCoreApplication.instance().quit()
self.centralwidget.startvid()
class CentralWidget(QWidget):
def __init__(self,args):
super(CentralWidget, self).__init__()
self.layout = QVBoxLayout()
self.layout.setAlignment(Qt.AlignCenter)
self.setLayout(self.layout)
self.player = QMediaPlayer(None, QMediaPlayer.VideoSurface)
self.vw = QVideoWidget()
self.player.setVideoOutput(self.vw)
def startvid(self):
self.layout.addWidget(self.vw)
url= QUrl.fromLocalFile(glob.glob("videos/*")[0])
content= QMediaContent(url)
self.player.setMedia(content)
self.player.setVideoOutput(self.vw)
self.player.play()
if __name__== "__main__":
parser = argparse.ArgumentParser()
#~ parser.add_argument("-nb","--nobox",action="store_true", help="do not wait for the box connection")
args = parser.parse_args()
app = QApplication(sys.argv)
mainwindow = MainWindow(args)
#~ mainwindow.showFullScreen()
mainwindow.show()
sys.exit(app.exec_())
I tried to paste the minimal code. The thing is, I press the button nothing shows, although I used examples like this one PyQt5 - Can't play video using QVideoWidget to test if playing the video is ok, and these work. It's as if it is not adding the widget to the layout or something. Any idea what might be wrong?
I had to use QGraphicsView to achieve what I wanted, here is a fix:
from PyQt5.QtCore import *
from PyQt5.QtGui import *
from PyQt5.QtWidgets import *
from PyQt5.QtMultimedia import *
from PyQt5.QtMultimediaWidgets import *
import glob
class MainWindow(QMainWindow):
def __init__(self):
super(MainWindow, self).__init__()
self.setWindowTitle('Navon test')
self.setWindowFlags(Qt.FramelessWindowHint)
# exit option for the menu bar File menu
self.exit = QAction('Exit', self)
self.exit.setShortcut('Ctrl+q')
# message for the status bar if mouse is over Exit
self.exit.setStatusTip('Exit program')
# newer connect style (PySide/PyQT 4.5 and higher)
self.exit.triggered.connect(app.quit)
self.setWindowIcon(QIcon('icon.ico'))
self.centralwidget = VideoPlayer()
self.setCentralWidget(self.centralwidget)
def keyPressEvent(self, QKeyEvent):
if QKeyEvent.key() == Qt.Key_Escape:
self.centralwidget.phaseQuit(2)
self.centralwidget.play()
class VideoPlayer(QWidget):
def __init__(self, parent=None):
super(VideoPlayer, self).__init__(parent)
self.mediaPlayer = QMediaPlayer(None, QMediaPlayer.VideoSurface)
self.videoItem = QGraphicsVideoItem()
self.videoItem.setSize(QSizeF(640, 480))
scene = QGraphicsScene(self)
graphicsView = QGraphicsView(scene)
scene.addItem(self.videoItem)
layout = QVBoxLayout()
layout.addWidget(graphicsView)
self.setLayout(layout)
self.mediaPlayer.setVideoOutput(self.videoItem)
self.counter = 0
def play(self):
if self.mediaPlayer.state() == QMediaPlayer.PlayingState:
pass
else:
self.mediaPlayer.setMedia(QMediaContent(QUrl.fromLocalFile(glob.glob("videos/*")[self.counter])))
self.mediaPlayer.play()
self.counter += 1
if __name__ == '__main__':
import sys
app = QApplication(sys.argv)
player = MainWindow()
player.show()
sys.exit(app.exec_())