I've been looking through answers for a while but couldn't find a solution to my problem. I recently started playing around with PyQt and trying to code out couple of ideas, one of which was to have a couple of buttons with some text on them and when a button is clicked, its text would change color. Here is my code:
import sys
from PyQt5 import QtWidgets, QtGui
from PyQt5.QtWidgets import (QApplication, QWidget, QPushButton, QLabel, QMainWindow,
QHBoxLayout, QGroupBox, QDialog, QVBoxLayout, QGridLayout, QMessageBox)
from PyQt5.QtCore import pyqtSlot, Qt
class App(QDialog):
def __init__(self):
super().__init__()
self.title = "Battleship"
self.left = 50
self.top = 50
self.width = 750
self.height = 500
self.initUI()
def initUI(self):
self.setGeometry(self.left, self.top, self.width, self.height)
self.setWindowTitle(self.title)
self.setFixedSize(self.width, self.height)
stylesheet = """QPushButton {background: #EEE; color: #11}
!QPushButton {background: #555; color: #EEE}"""
self.setStyleSheet(stylesheet)
self.grid()
layout = QVBoxLayout()
layout.addWidget(self.box)
self.setLayout(layout)
self.show()
def grid(self):
self.box = QGroupBox()
self.layout = QGridLayout()
self.box.setLayout(self.layout)
self.button1 = QPushButton('X', self)
self.button2 = QPushButton('X', self)
self.button3 = QPushButton('X', self)
self.button1.clicked.connect(self.pick)
self.button2.clicked.connect(self.pick)
self.button3.clicked.connect(self.pick)
self.layout.addWidget(self.button1)
self.layout.addWidget(self.button2)
self.layout.addWidget(self.button3)
def pick(self):
# turn 'X' from black to red ONLY on the clicked button
# while leaving the others untouched
pass
#---------------------------------------------------------------
if __name__ == '__main__':
app = QApplication(sys.argv)
gui = App()
sys.exit(app.exec_())
What does the 'pick' function have to look like in order to do this? To clarify: I don't want to make three individual functions, one for each button (as it would be very impractical for a larger number of buttons), but a single function which would work with any button.
the sender() method returns us the object that emits the signal, in your case the button will be pressed:
def pick(self):
# turn 'X' from black to red ONLY on the clicked button
# while leaving the others untouched
btn = self.sender()
btn.setStyleSheet("color: red")
Related
I have a PyQT application with a toolbar, a set of buttons, and a bottom row of additional buttons. I'd like to add a TextEdit underneath the bottom row that the user can hide or show. I would like the TextEdit to extend the bottom portion when being shown but, when the user hides it, I would like that bottom portion removed without affecting the height, width, or sizing of any other of the buttons. Imagine just taking a pair of scissors to the TextEdit section when the user hides it but then gluing it back on when the user wants it back. Is this even possible to do in PyQt? The closest I've found is the implementation below which resizes all the buttons.
from PyQt5.QtCore import Qt, QPoint, QTimer, QThread, QSize
from PyQt5.QtGui import QFont, QImage, QPainter, QPen, QPixmap
from PyQt5.QtWidgets import (
QAction, QApplication, QCheckBox, QFileDialog, QHBoxLayout, QLabel,
QMainWindow, QMenu, QMenuBar, QPlainTextEdit, QPushButton, QSpacerItem,
QSizePolicy, QFrame,
QTextEdit, QVBoxLayout, QWidget, QGridLayout, QToolButton, QComboBox
)
from PyQt5.QtWidgets import QApplication
import sys
class AppWindow(QMainWindow):
def __init__(self, main_widget):
super(AppWindow, self).__init__()
self.main_widget = main_widget
self.setCentralWidget(self.main_widget)
class AppWidget(QWidget):
def __init__(self, panels=[]):
super(AppWidget, self).__init__()
self.panels = panels
self.main_layout = QVBoxLayout(self)
self.setSizePolicy(
QSizePolicy.MinimumExpanding,
QSizePolicy.MinimumExpanding
)
self.toolbar_frame = QFrame(self)
self.toolbar_frame_layout = QHBoxLayout(self.toolbar_frame)
self.toolbar_frame_layout.addStretch()
self.log_button = QToolButton(self.toolbar_frame)
self.log_button.setText('Toggle Log')
self.toolbar_frame_layout.addWidget(self.log_button)
self.toolbar_frame.setLayout(self.toolbar_frame_layout)
self.project_frame = QFrame(self)
self.project_frame_layout = QHBoxLayout(self.project_frame)
self.project_dropdown = QComboBox(self.project_frame)
self.project_dropdown.setMinimumSize(20, 0)
self.project_refresh = QToolButton(self.project_frame)
self.project_refresh.setText('Refresh')
self.project_frame_layout.addWidget(self.project_dropdown)
self.project_frame_layout.addWidget(self.project_refresh)
self.project_frame.setLayout(self.project_frame_layout)
self.panel_frame = QFrame(self)
self.panel_frame_layout = QVBoxLayout(self.panel_frame)
for panel in panels:
self.panel_frame_layout.addWidget(panel)
self.panel_frame.setLayout(self.panel_frame_layout)
self.bottom_frame = QFrame(self)
self.bottom_frame_layout = QHBoxLayout(self.bottom_frame)
self.bottom_frame_layout.addStretch()
self.sg_button = QToolButton()
self.sg_button.setText('Extra Stuff')
self.bottom_frame_layout.addWidget(self.sg_button)
self.bottom_frame.setLayout(self.bottom_frame_layout)
self.log = QTextEdit()
self.log_frame = QFrame(self)
self.log_frame_layout = QHBoxLayout(self.log_frame)
self.log_frame_layout.addWidget(self.log)
self.log_frame.setLayout(self.log_frame_layout)
self.main_layout.addWidget(self.toolbar_frame)
self.main_layout.addWidget(self.project_frame)
self.main_layout.addWidget(self.panel_frame)
self.main_layout.addWidget(self.bottom_frame)
self.app_widgets = QWidget(self)
self.app_widgets.setLayout(self.main_layout)
self.log_widget = QWidget(self)
self.log_widget.setLayout(self.log_frame_layout)
self.total_layout = QVBoxLayout(self)
self.total_layout.addWidget(self.app_widgets)
self.total_layout.addWidget(self.log_widget)
self.setLayout(self.total_layout)
self.log_button.clicked.connect(self.toggle_log)
def toggle_log(self):
if self.log_widget.isHidden():
self.log_widget.show()
QTimer.singleShot(0, self.resize_show)
else:
self.log_widget.hide()
QTimer.singleShot(0, self.resize_hide)
# self.adjustSize() Also does not work.
def resize_show(self):
self.resize(self.width(), self.sizeHint().height())
def resize_hide(self):
self.resize(self.width(), self.minimumSizeHint().height())
class AppPanel(QWidget):
def __init__(self, sections=[]):
super(AppPanel, self).__init__()
self.setSizePolicy(
QSizePolicy.MinimumExpanding,
QSizePolicy.MinimumExpanding
)
self.layout = QVBoxLayout(self)
self.setLayout(self.layout)
self.sections = sections
for section in self.sections:
self.layout.addWidget(section)
class AppSection(QWidget):
def __init__(self, buttons=[]):
super(AppSection, self).__init__()
self.setSizePolicy(
QSizePolicy.MinimumExpanding,
QSizePolicy.MinimumExpanding
)
self.buttons = buttons
self.layout = QGridLayout()
for i, button in enumerate(self.buttons):
col = i % 2
row = i // 2
self.layout.addWidget(button, row, col)
self.setLayout(self.layout)
class AppButton(QToolButton):
def __init__(self, text=''):
super(AppButton, self).__init__()
self.setText(text)
self.setFocusPolicy(Qt.NoFocus)
self.setIconSize(QSize(50, 50))
self.setToolButtonStyle(Qt.ToolButtonTextBesideIcon)
self.setSizePolicy(QSizePolicy.MinimumExpanding, QSizePolicy.MinimumExpanding)
if __name__ == '__main__':
app = QApplication(sys.argv)
app_buttons = [AppButton(text='APPS ' + str(i)) for i in range(5)]
custom_btns = [AppButton(text='Custom ' + str(i)) for i in range(5)]
app_section = AppSection(buttons=app_buttons)
custom_section = AppSection(buttons=custom_btns)
panels = [AppPanel(sections=[app_section, custom_section])]
ex = AppWidget(panels=panels)
lw = AppWindow(main_widget=ex)
lw.show()
app.exec_()
Resizing the widget alone is not a valid solution, because it only overrides the geometry set by the layout without notifying the parent widget.
This is also important as you should not resize the widget based on its hint alone when showing the log: if you increase the size of the window while the log is hidden and then show it again, it will not occupy all the available space.
What you need to do is to access the top level window, force its layout to lay out its contents again, and use its hint to for the resize.
def resize_hide(self):
self.window().layout().activate()
self.window().resize(
self.window().width(),
self.window().minimumSizeHint().height()
)
You can set the alignment policy for your top widget:
[...]
self.total_layout.setAlignment(self.app_widgets, Qt.AlignTop)
self.setLayout(self.total_layout)
[...]
The app_widget will not be resized anymore when you hide your text edit.
This question already has an answer here:
PyQt TypeError connect()
(1 answer)
Closed 2 years ago.
this is the full code, i don't know why i can't use that clicked.connect on my mind, that's still logic '-' but why!!!???
from PyQt5 import QtGui
from PyQt5.QtWidgets import QApplication, QWidget, QScrollArea, QVBoxLayout, QGroupBox, QLabel, QPushButton, QFormLayout
import sys
class Window(QWidget):
def __init__(self, val):
super().__init__()
self.title = "PyQt5 Scroll Bar"
self.top = 200
self.left = 500
self.width = 400
self.height = 300
self.setWindowIcon(QtGui.QIcon("icon.png"))
self.setWindowTitle(self.title)
self.setGeometry(self.left, self.top, self.width, self.height)
formLayout = QFormLayout()
groupBox = QGroupBox("This Is Group Box")
labelLis = []
comboList = []
for i in range(val):
labelLis.append(QLabel("Label"))
comboList.append(QPushButton("Click Me").clicked.connect(print("hello")))
formLayout.addRow(labelLis[i], comboList[i])
groupBox.setLayout(formLayout)
scroll = QScrollArea()
scroll.setWidget(groupBox)
scroll.setWidgetResizable(True)
scroll.setFixedHeight(400)
layout = QVBoxLayout(self)
layout.addWidget(scroll)
self.show()
App = QApplication(sys.argv)
window = Window(30)
sys.exit(App.exec())
and i got error in here, i wanna make every each item can clicked, but i don't know why this happen :"D
for i in range(val):
labelLis.append(QLabel("Label"))
comboList.append(QPushButton("Click Me").clicked.connect(print("hello")))
formLayout.addRow(labelLis[i], comboList[i])
groupBox.setLayout(formLayout)
this code not working, comboList.append(QPushButton("Click Me").clicked.connect(print("hello")))
I don’t know why comboList.append(QPushButton("Click Me").clicked.connect(self.hello) error occurs
But i will do
qbutton = QPushButton("Click Me")
qbutton.clicked.connect(self.hello)
result
from PyQt5 import QtGui
from PyQt5.QtWidgets import QApplication, QWidget, QScrollArea, QVBoxLayout, QGroupBox, QLabel, QPushButton, QFormLayout
import sys
class Window(QWidget):
def __init__(self, val):
super().__init__()
self.title = "PyQt5 Scroll Bar"
self.top = 200
self.left = 500
self.width = 400
self.height = 300
self.setWindowIcon(QtGui.QIcon("icon.png"))
self.setWindowTitle(self.title)
self.setGeometry(self.left, self.top, self.width, self.height)
formLayout = QFormLayout()
groupBox = QGroupBox("This Is Group Box")
labelLis = []
comboList = []
for i in range(val):
qbutton = QPushButton("Click Me")
qbutton.clicked.connect(self.hello)
labelLis.append(QLabel("Label"))
comboList.append(qbutton)
formLayout.addRow(labelLis[i], comboList[i])
groupBox.setLayout(formLayout)
scroll = QScrollArea()
scroll.setWidget(groupBox)
scroll.setWidgetResizable(True)
scroll.setFixedHeight(400)
layout = QVBoxLayout(self)
layout.addWidget(scroll)
self.show()
def hello(self):
print('hello')
App = QApplication(sys.argv)
window = Window(30)
sys.exit(App.exec())
from PyQt5.QtWidgets import QApplication, QLabel, QWidget, QFileDialog, QPushButton, QLineEdit,QVBoxLayout, QHBoxLayout
from PyQt5.QtCore import *
from PyQt5.QtGui import QPixmap
from PyQt5.QtWidgets import QApplication, QWidget, QPushButton, QDialog, QVBoxLayout
import Updated_encrypt
import sys
class Window(QWidget):
def __init__(self):
super().__init__()
self.title = 'Encrypt/Decrypt'
self.top = 200
self.left = 500
self.width = 400
self.height = 300
self.InitWindow()
def InitWindow(self):
self.setWindowTitle(self.title)
self.setGeometry(self.left, self.top, self.width, self.height)
vbox = QVBoxLayout()
self.button1 = QPushButton('Encrypt')
self.button1.clicked.connect(self.openSecondDialog)
self.button2 = QPushButton('Decrypt')
vbox.addWidget(self.button1)
vbox.addWidget(self.button2)
self.setLayout(vbox)
self.show()
def openSecondDialog(self):
hbox = QVBoxLayout()
mydialog = QDialog(self)
mydialog.show()
self.button2 = QPushButton('Check Image')
self.button2.clicked.connect(self.getImage)
hbox.addWidget(self.button2)
self.setLayout(hbox)
self.show()
def getImage(self):
hbox = QHBoxLayout()
file_Name = QFileDialog.getOpenFileName(self,
'OpenFile',
'',
'')
image_path = file_Name[0]
updatedImage = Updated_encrypt.decrypt(image_path, 123)
pixmap = QPixmap(updatedImage)
self.label.setPixmap(QPixmap(pixmap))
self.resize(pixmap.width(), pixmap.height())
App = QApplication(sys.argv)
window = Window()
sys.exit(App.exec())
I have my code set up to implement an algorithm to modify an image when my I select it from my pop up dialogue. What I am trying to accomplish is for the image to pop up in a separate window when I click the encrypt button. I can't seem to get anything to pop up in the separate window aside from the window itself. Any help would be appreciated.
You have at least the following errors:
The "hbox" created is being added to the window and not to the QDialog: self.setLayout(hbox), it must be mydialog.setLayout(hbox).
Do not use the same name for 2 different objects as they can cause problems, in your case there are 2 QPushButton assigned to the variable "self.button2".
You try to use the variable "self.label" but never believe it.
Considering the above we can make the following improvements:
Use more descriptive names to easily distinguish their function.
If you are going to have a window that has a different objective, it is better to create a class.
The above avoid the indicated problems, considering the above the solution is:
import sys
from PyQt5.QtGui import QPixmap
from PyQt5.QtWidgets import (
QApplication,
QDialog,
QFileDialog,
QHBoxLayout,
QLabel,
QPushButton,
QVBoxLayout,
QWidget,
)
import Updated_encrypt
class Dialog(QDialog):
def __init__(self, parent=None):
super().__init__(parent)
self.load_image_btn = QPushButton("Check Image")
self.load_image_btn.clicked.connect(self.load_image)
self.image_lbl = QLabel()
lay = QVBoxLayout(self)
lay.addWidget(self.load_image_btn)
lay.addWidget(self.image_lbl)
def load_image(self):
image_path, _ = QFileDialog.getOpenFileName(self, "OpenFile", "", "")
if image_path:
updatedImage = Updated_encrypt.decrypt(image_path, 123)
pixmap = QPixmap(updatedImage)
self.image_lbl.setPixmap(QPixmap(pixmap))
class Window(QWidget):
def __init__(self, parent=None):
super().__init__(parent)
self.title = "Encrypt/Decrypt"
self.InitWindow()
def InitWindow(self):
self.setWindowTitle(self.title)
self.setGeometry(200, 500, 400, 300)
self.encrypt_btn = QPushButton("Encrypt")
self.encrypt_btn.clicked.connect(self.openSecondDialog)
self.decrypt_btn = QPushButton("Decrypt")
vbox = QVBoxLayout(self)
vbox.addWidget(self.encrypt_btn)
vbox.addWidget(self.decrypt_btn)
def openSecondDialog(self):
dialog = Dialog(self)
dialog.show()
if __name__ == "__main__":
app = QApplication(sys.argv)
window = Window()
window.show()
sys.exit(app.exec())
I am trying to create a pop-up window that gets popped-up from pressing on a QPushButton. However, I have a separate QPushButton class that I would like to use. I can't seem to get it working. Anything I am doing wrong?
#import ... statements
import sys
# from ... import ... statements
from PyQt5.QtWidgets import (QMainWindow, QApplication, QPushButton, QGridLayout, QWidget, QHBoxLayout, QLabel,
QVBoxLayout)
from PyQt5.QtCore import Qt
from PyQt5.QtGui import QFont, QFontDatabase, QColor, QPalette, QMovie
from skimage import transform, io
# Create main window of the widget
class MainWindow(QWidget):
def __init__(self):
super().__init__()
#Set a title inside the widget
self.titleLabel = QLabel()
titleText = "some title text"
self.titleLabel.setText(titleText)
# Give the label some flair
self.titleLabel.setFixedWidth(1000)
self.titleLabel.setAlignment(Qt.AlignCenter)
QFontDatabase.addApplicationFont(link_to_custom_font)
font = QFont()
font.setFamily("custom_font_name")
font.setPixelSize(50)
self.titleLabel.setFont(font)
# Set first button - The "Yes" Button
self.btn1 = myButtonOne("Yes")
#Initialize GUI
self.layoutGUI()
self.initUI()
def initUI(self):
self.fromleft = 200
self.fromtop = 100
self.w = 1000
self.h = 500
self.setGeometry(self.fromleft, self.fromtop, self.w, self.h)
def layoutGUI(self):
hbox = QHBoxLayout()
hbox.setSpacing(20)
hbox.addWidget(self.btn1)
vbox = QVBoxLayout()
vbox.addWidget(self.titleLabel)
vbox.addLayout(hbox)
self.setLayout(vbox)
class myButtonOne(QPushButton):
def __init__(self, parent=None):
super(myButtonOne, self).__init__(parent)
# Set maximum border size
imSize = io.imread(imagePath)
imHeight = imSize.shape[1]
imWidth = imSize.shape[0]
# Set first button - The "Yes" Button
yesImage = someImagePath
self.setStyleSheet("background-image: url(" + yesImage + ");"
"background-repeat: none;"
"background-position: center;"
"border: none")
self.setFixedSize(imWidth, imHeight)
self.clicked.connect(self.buttonOnePushed)
def buttonOnePushed(self):
textView().show()
def enterEvent(self, event):
newImage = someOtherImagePath
self.setStyleSheet("background-image: url("+newImage+");"
"background-repeat: none;"
"background-position: center;"
"border: none")
def leaveEvent(self, event):
newImage = someImagePath
self.setStyleSheet("background-image: url("+newImage+");"
"background-repeat: none;"
"background-position: center;"
"border: none")
class textView(QWidget):
def __init(self):
textView.__init__()
theText = QLabel()
#define sizes
self.height = 550
self.width = 250
# Open QWidget
self.initUI()
# Set the text for the QLabel
someText = "Some Text for the label"
theText.setText(someText)
def initUI(self):
self.show()
# Start GUI
if __name__ == '__main__':
app = QApplication(sys.argv)
win = MainWindow()
win.show()
sys.exit(app.exec_())
So, I am trying to keep the QPushButton classes separate, so that I can customize them. I would like to keep it like that, especially to keep it clean and readable.
First off - please read: How to create a Minimal, Complete, and Verifiable example. I had a lot of work minimizing your code, which wasted a good amount of my time.
Nonetheless, here is a minimal working code, with your own button class:
import sys
from PyQt5.QtWidgets import QApplication, QPushButton, QWidget, QLabel, QVBoxLayout
class MainWindow(QWidget):
def __init__(self):
super(MainWindow, self).__init__()
self.titleLabel = QLabel( "some label text" )
self.btn1 = myButtonOne( "button text" )
hbox = QVBoxLayout() # one vertical box seemed enough
hbox.addWidget( self.titleLabel )
hbox.addWidget( self.btn1 )
self.setLayout( hbox )
class myButtonOne(QPushButton):
def __init__(self, text, parent=None):
super(myButtonOne, self).__init__(text, parent)
self.clicked.connect(self.buttonOnePushed)
# add your customizations here
def buttonOnePushed (self) :
self.t = textView()
self.t.show()
class textView(QWidget):
def __init__(self):
super(textView, self).__init__()
self.theText = QLabel('test', self )
if __name__ == '__main__':
app = QApplication(sys.argv)
win = MainWindow()
win.show()
sys.exit(app.exec_())
What have you done wrong in your code?
using textView().show() creates a local version of you textView-class and show()'s it:
def buttonOnePushed(self):
textView().show()
But, show() means that the code continues, where the end of your code comes, which results in cleaning up the locals. End - it's just shown for a microsecond.
def buttonOnePushed (self) :
self.t = textView()
self.t.show()
The code above stores the var as instance-attribute of the button, which is not cleaned up.
Furthermore you misspelled the init in your textView-class:
"__init" should be __init__ - else it is not called when using the constructor:
class textView(QWidget):
def __init(self):
textView.__init__()
Finally, you wanted to called show() twice:
in your textView-init you call initUI() which is calling show()
you calling show manually with textView().show()
Hope this helps! I did not include your personal style adjustments for readability.
Can someone help me figure out how to combine layouts?
Taking offset from the guides from: [https://pythonspot.com/en/pyqt5/]
I would rather not use Designer as the layout is going to be a part of several tabs that is determined based on the amount of tests and data sets from a specified data folder.
For example, I would like to switch out the Blue button in:
import sys
from PyQt5.QtWidgets import QApplication, QWidget, QPushButton, QHBoxLayout, QGroupBox, QDialog, QVBoxLayout
from PyQt5.QtGui import QIcon
from PyQt5.QtCore import pyqtSlot
class App(QDialog):
def __init__(self):
super().__init__()
self.title = 'PyQt5 layout - pythonspot.com'
self.left = 10
self.top = 10
self.width = 320
self.height = 100
self.initUI()
def initUI(self):
self.setWindowTitle(self.title)
self.setGeometry(self.left, self.top, self.width, self.height)
self.createHorizontalLayout()
windowLayout = QVBoxLayout()
windowLayout.addWidget(self.horizontalGroupBox)
self.setLayout(windowLayout)
self.show()
def createHorizontalLayout(self):
self.horizontalGroupBox = QGroupBox("What is your favorite color?")
layout = QHBoxLayout()
buttonBlue = QPushButton('Blue', self)
buttonBlue.clicked.connect(self.on_click)
layout.addWidget(buttonBlue)
buttonRed = QPushButton('Red', self)
buttonRed.clicked.connect(self.on_click)
layout.addWidget(buttonRed)
buttonGreen = QPushButton('Green', self)
buttonGreen.clicked.connect(self.on_click)
layout.addWidget(buttonGreen)
self.horizontalGroupBox.setLayout(layout)
#pyqtSlot()
def on_click(self):
print('PyQt5 button click')
if __name__ == '__main__':
app = QApplication(sys.argv)
ex = App()
sys.exit(app.exec_())
with the grid layout from:
import sys
from PyQt5.QtWidgets import QApplication, QWidget, QPushButton, QHBoxLayout, QGroupBox, QDialog, QVBoxLayout, QGridLayout
from PyQt5.QtGui import QIcon
from PyQt5.QtCore import pyqtSlot
class App(QDialog):
def __init__(self):
super().__init__()
self.title = 'PyQt5 layout - pythonspot.com'
self.left = 10
self.top = 10
self.width = 320
self.height = 100
self.initUI()
def initUI(self):
self.setWindowTitle(self.title)
self.setGeometry(self.left, self.top, self.width, self.height)
self.createGridLayout()
windowLayout = QVBoxLayout()
windowLayout.addWidget(self.horizontalGroupBox)
self.setLayout(windowLayout)
self.show()
def createGridLayout(self):
self.horizontalGroupBox = QGroupBox("Grid")
layout = QGridLayout()
layout.setColumnStretch(1, 4)
layout.setColumnStretch(2, 4)
layout.addWidget(QPushButton('1'),0,0)
layout.addWidget(QPushButton('2'),0,1)
layout.addWidget(QPushButton('3'),0,2)
layout.addWidget(QPushButton('4'),1,0)
layout.addWidget(QPushButton('5'),1,1)
layout.addWidget(QPushButton('6'),1,2)
layout.addWidget(QPushButton('7'),2,0)
layout.addWidget(QPushButton('8'),2,1)
layout.addWidget(QPushButton('9'),2,2)
self.horizontalGroupBox.setLayout(layout)
if __name__ == '__main__':
app = QApplication(sys.argv)
ex = App()
sys.exit(app.exec_())
You can add a layout as an element of another layout in a similar fashion to adding a widget by using addLayout()
layout = QtWidgets.QHBoxLayout()
sublayout = QtWidgets.QGridLayout()
layout.addLayout(sublayout)