I want to embed an Ipython terminal in a QT widget so I can access objects in my QT application. I understand that this is possible with examples such as this: https://github.com/gpoulin/python-test/blob/master/embedded_qtconsole.py
however, if the kernel is blocking (in an infinite while loop for example) the whole application is unresponsive and can only be killed with a keyboard interrupt from the terminal where the qt application was run. If I use the QtKernelManager instead of QtInProcessKernelManager I can successfully interrupt the kernel from the qt application, however, I cannot access objects within it as the kernel is embedded in a different process.
Is there a way to catch the keyboard interrupt when embedding the IPython terminal in the same process ? or should I use a different implementation of embedding the kernel ?
my adapted code is below
import os
os.environ['QT_API'] = 'pyqt'
import sip
sip.setapi("QString", 2)
sip.setapi("QVariant", 2)
import sys
from PyQt4 import QtGui, QtCore
from pkg_resources import require
require('ipython')
from IPython.qt.console.rich_ipython_widget import RichIPythonWidget
from IPython.qt.inprocess import QtInProcessKernelManager
class IPythonWidget(QtGui.QWidget):
def __init__(self, **kwarg):
super(IPythonWidget, self).__init__()
self.initUI()
def startIpKernel(self):
self.kernel_manager = QtInProcessKernelManager()
self.kernel_manager.start_kernel()
self.kernel_manager.kernel.gui = 'qt4'
self.kernel_client = kernel_client = self.kernel_manager.client()
self.kernel_client.start_channels()
def initUI(self):
self.startIpKernel()
self.addWidgets()
def addWidgets(self):
self.button = QtGui.QPushButton()
self.button.setText("test button")
self.console = RichIPythonWidget(self)
self.console.kernel_manager =self.kernel_manager
self.console.kernel_client = self.kernel_client
self.console.kernel_manager.kernel.shell.push({"button": self.button})#this can be wrapped into another method
vbox = QtGui.QVBoxLayout()
vbox.addWidget(self.console)
vbox.addWidget(self.button)
self.setLayout(vbox)
def mousePressEvent(self, event):
self.mousepos = event.pos()
if __name__ == '__main__':
app = QtGui.QApplication(sys.argv)
ex = IPythonWidget()
ex.show()
sys.exit(app.exec_())
Related
Using QVideoWidget in PySide2 (although the python part may not be significant). I've set up my hotkeys using QShortcut, and it all works great. When I press 'F' to enter full-screen mode that works too, but then I can't leave. None of my hotkeys or mouse event handlers work. I end up stuck in full-screen mode.
Is there a way to allow it to respond even in full-screen mode? Have I gone about creating my hotkeys the wrong way?
This example demonstrates the issue:
class MainWindow(QWidget):
def __init__(self):
super().__init__()
self._fullscreen = False
self.movie_display = QVideoWidget(self)
self.movie_handler = QMediaPlayer()
self.movie_handler.setVideoOutput(self.movie_display)
layout = QVBoxLayout()
layout.addWidget(self.movie_display)
self.setLayout(layout)
QShortcut(QKeySequence(QtConsts.Key_F), self, self.toggle_fullscreen)
s = 'test.webm'
s = os.path.join(os.path.dirname(__file__), s)
local = QUrl.fromLocalFile(s)
media = QMediaContent(local)
self.movie_handler.setMedia(media)
self.movie_handler.play()
def toggle_fullscreen(self):
self._fullscreen = not self._fullscreen
self.movie_display.setFullScreen(self._fullscreen)
The problem is that the shortcut is set in the window but when full-screen is set in the QVideoWidget 2 windows are created: The original window and the window where the QVideoWidget is in full-screen. One possible solution is to set the QShortcut in the QVideoWidget or establish that the context of the QShortcut is Qt::ApplicationShortcut:
import os
from PyQt5 import QtCore, QtGui, QtWidgets, QtMultimedia, QtMultimediaWidgets
CURRENT_DIR = os.path.dirname(os.path.realpath(__file__))
class MainWindow(QtWidgets.QWidget):
def __init__(self):
super().__init__()
self._fullscreen = False
self.movie_display = QtMultimediaWidgets.QVideoWidget()
self.movie_handler = QtMultimedia.QMediaPlayer(
self, QtMultimedia.QMediaPlayer.VideoSurface
)
self.movie_handler.setVideoOutput(self.movie_display)
layout = QtWidgets.QVBoxLayout(self)
layout.addWidget(self.movie_display)
QtWidgets.QShortcut(
QtGui.QKeySequence(QtCore.Qt.Key_F),
self.movie_display,
self.toggle_fullscreen,
)
# or
"""QtWidgets.QShortcut(
QtGui.QKeySequence(QtCore.Qt.Key_F),
self,
self.toggle_fullscreen,
context=QtCore.Qt.ApplicationShortcut
)"""
file = os.path.join(os.path.dirname(os.path.realpath(__file__)), "test.webm")
media = QtMultimedia.QMediaContent(QtCore.QUrl.fromLocalFile(file))
self.movie_handler.setMedia(media)
self.movie_handler.play()
def toggle_fullscreen(self):
self._fullscreen = not self._fullscreen
self.movie_display.setFullScreen(self._fullscreen)
if __name__ == "__main__":
import sys
app = QtWidgets.QApplication(sys.argv)
w = MainWindow()
w.show()
sys.exit(app.exec_())
I'm trying to create application which runs block of code every X seconds, which has system tray icon with only "Quit" option. But the problem is that when it get to the tray function, it doesn't read next lines of code, and as a result, "While" loop can't be launched.
Is there any other approach to do that?
import time
import os
import sys
from PySide2 import QtWidgets, QtGui
class SystemTrayIcon(QtWidgets.QSystemTrayIcon):
def __init__(self, icon, parent=None):
QtWidgets.QSystemTrayIcon.__init__(self, icon, parent)
self.setToolTip(f'Wallpy')
menu = QtWidgets.QMenu(parent)
exit_ = menu.addAction("Exit")
exit_.triggered.connect(lambda: sys.exit())
menu.addSeparator()
self.setContextMenu(menu)
def tray():
app = QtWidgets.QApplication(sys.argv)
w = QtWidgets.QWidget()
tray_icon = SystemTrayIcon(QtGui.QIcon("tray.ico"), w)
tray_icon.show()
app.exec_()
def loop_function():
print("Nice") # anything executable
tray() # launch tray icon
while True:
loop_function() # executing every minute
time.sleep(60)
Its because, when you used the tray(), your main application started and the GUI main loop is initiated. It runs till your application exits, after which the while loop is executed.
However, if you want the loop to run simultaneously, you should integrate it with Qt's main loop. In Gtk we do this using GLib.add_main_thread and other methods, I don't know about Qt, but you can use this general solution using Threading.
from threading import Thread
import time
import os
import sys
from PySide2 import QtWidgets, QtGui
def loop_function():
print("Nice") # anything executable
def thread_loop():
while True:
loop_function() # executing every minute
time.sleep(60)
class SystemTrayIcon(QtWidgets.QSystemTrayIcon):
def __init__(self, icon, parent=None):
QtWidgets.QSystemTrayIcon.__init__(self, icon, parent)
self.setToolTip(f'Wallpy')
menu = QtWidgets.QMenu(parent)
exit_ = menu.addAction("Exit")
exit_.triggered.connect(lambda: sys.exit())
menu.addSeparator()
self.setContextMenu(menu)
def tray():
app = QtWidgets.QApplication(sys.argv)
w = QtWidgets.QWidget()
tray_icon = SystemTrayIcon(QtGui.QIcon("tray.ico"), w)
tray_icon.show()
app.exec_()
my_loop = Thread(target=thread_loop, args=()) # Start the thread with no args
my_loop.start()
tray() # launch tray icon
I have a small script that is designed to embed an xterm in a PyQt GUI. On Linux, it works, creating a GUI like this:
However, running the same script on OS X yields two windows like this:
Does anyone know how to address this and prevent OS X from screwing up the GUI?
import sys
from PyQt4.QtCore import *
from PyQt4.QtGui import *
class embeddedTerminal(QWidget):
def __init__(self):
QWidget.__init__(self)
self.resize(800, 600)
self.process = QProcess(self)
self.terminal = QWidget(self)
layout = QVBoxLayout(self)
layout.addWidget(self.terminal)
self.process.start('xterm', ['-into', str(self.terminal.winId())])
if __name__ == "__main__":
app = QApplication(sys.argv)
main = embeddedTerminal()
main.show()
sys.exit(app.exec_())
You could take a look at the qtconsole front end for Jupyter and try to use the bash kernel. Depending on your end goal, I know it is possible to embed an IPython kernel, in another application.
I am wondering how one would create a GUI application, and interact with it from the console that started it.
As an example, I would like to create a GUI in PyQt and work with it from the console. This could be for testing settings without restarting the app, but in larger projects also for calling functions etc.
Here is a simple example using PyQt:
import sys
from PyQt4 import QtGui
def main():
app = QtGui.QApplication(sys.argv)
w = QtGui.QWidget()
w.show()
sys.exit(app.exec_())
if __name__ == '__main__':
main()
when this is run with python -i example.py the console is blocked as long as the main-loop is executed.
How can I call w.resize(100,100) while the GUI is running?
ops, posted wrong answer before
there is a post in Stack about that
Execute Python code from within PyQt event loop
The following example uses the code module to run a console in the command prompt (be sure to run the script from the command line). Subclassing QThread provides a route by which the console can be run in a separate thread from that of the main GUI and enables some interaction with it. The stub example below should be easy enough to incorporate into a larger packaged PyQt program.
from PyQt5.QtWidgets import *
from PyQt5.QtCore import *
import threading #used only to id the active thread
import code
import sys
class Worker(QThread): #Subclass QThread and re-define run()
signal = pyqtSignal()
def __init__(self):
super().__init__()
def raise_sys_exit(self): #more gracefully exit the console
print('(Deactivated Console)')
raise SystemExit
def setup_console(self,global_dict):
console_exit = {'exit': self.raise_sys_exit}
self.console = code.InteractiveConsole(locals=dict(global_dict,**console_exit))
def run(self):
try:
print('worker', threading.get_ident())
self.console.interact()
except SystemExit:
self.signal.emit()
class MainWindow(QMainWindow):
def __init__(self, *args, **kwargs):
super(MainWindow, self).__init__(*args,**kwargs)
self.data = [1,2,3,4] #some data we might want to look at
layout = QVBoxLayout()
self.b = QPushButton("Interact")
self.b.clicked.connect(self.b_clicked)
layout.addWidget(self.b)
w = QWidget()
w.setLayout(layout)
self.setCentralWidget(w)
self.worker = Worker()
self.worker.signal.connect(self.finished)
def finished(self):
self.b.setEnabled(True)
def b_clicked(self):
print('main',threading.get_ident())
self.worker.setup_console(globals()) #pass the global variables to the worker
self.worker.start()
self.b.setEnabled(False) #disable the GUI button until console is exited
if __name__ == '__main__':
app = QApplication(sys.argv)
window = MainWindow()
window.show()
app.exec_()
The easiest way is to use IPython:
ipython --gui=qt4
See ipython --help or the online documentation for more options (e.g. gtk, tk, etc).
I defined a print function using QPrinter and QDialog. However, when I launch the printer dialog and then press cancel, the entire mainwindow goes into not responding mode. I have tried to do QtGui.QPrintDialog.close() but does not work.
Code:
import sys
from PyQt4 import QtCore
from PyQt4 import QtGui
class QButton(QtGui.QWidget):
def __init__(self, parent=None):
QtGui.QWidget.__init__(self, parent)
self.button = QtGui.QPushButton('Button', self)
self.name='me'
self.button.clicked.connect(self.calluser)
def calluser(self):
Appli=QtGui.QApplication(sys.argv)
printer= QtGui.QPrinter()
doc=QtGui.QTextDocument("Set local variables in this printing slot." )
dialog = QtGui.QPrintDialog(printer)
dialog.setModal(True)
dialog.setWindowTitle("Print Document" )
if dialog.exec_() == True:
doc.print_(printer)
# dialog.addEnabledOption(QAbstractPrintDialog.PrintSelection)
def demo_QButton():
app = QtGui.QApplication(sys.argv)
tb = QButton()
tb.show()
app.exec_()
if __name__=='__main__':
demo_QButton()
You created a new application in the calluser method. Delete or comment the line:
Appli=QtGui.QApplication(sys.argv)
and try again. I think this time your main window will remain responsive.