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QT4 Table

We can show a table using the QTableWidget, part of the PyQt module.  We set the title, row count, column count and add the data.

Related course:

Qt4 Table example


An example below:

from PyQt4.QtGui import *
from PyQt4.QtCore import *
import sys

def main():
    app 	= QApplication(sys.argv)
    table 	= QTableWidget()
    tableItem 	= QTableWidgetItem()
    
    # initiate table
    table.setWindowTitle("QTableWidget Example @pythonspot.com")
    table.resize(400, 250)
    table.setRowCount(4)
    table.setColumnCount(2)
    
    # set data
    table.setItem(0,0, QTableWidgetItem("Item (1,1)"))
    table.setItem(0,1, QTableWidgetItem("Item (1,2)"))
    table.setItem(1,0, QTableWidgetItem("Item (2,1)"))
    table.setItem(1,1, QTableWidgetItem("Item (2,2)"))
    table.setItem(2,0, QTableWidgetItem("Item (3,1)"))
    table.setItem(2,1, QTableWidgetItem("Item (3,2)"))
    table.setItem(3,0, QTableWidgetItem("Item (4,1)"))
    table.setItem(3,1, QTableWidgetItem("Item (4,2)"))
    
    # show table
    table.show()
    return app.exec_()

if __name__ == '__main__':
    main()

Result:

PyQT Table PyQt Table

QTableWidget labels


You can set the header using the setHorizontalHeaderLabels() function. The same applies for vertical labels. A demonstration below:

from PyQt4.QtGui import *
from PyQt4.QtCore import *
import sys

def main():
    app 	= QApplication(sys.argv)
    table 	= QTableWidget()
    tableItem 	= QTableWidgetItem()
    
    # initiate table
    table.setWindowTitle("QTableWidget Example @pythonspot.com")
    table.resize(400, 250)
    table.setRowCount(4)
    table.setColumnCount(2)
    
    # set label
    table.setHorizontalHeaderLabels(QString("H1;H2;").split(";"))
    table.setVerticalHeaderLabels(QString("V1;V2;V3;V4").split(";"))
    
    # set data
    table.setItem(0,0, QTableWidgetItem("Item (1,1)"))
    table.setItem(0,1, QTableWidgetItem("Item (1,2)"))
    table.setItem(1,0, QTableWidgetItem("Item (2,1)"))
    table.setItem(1,1, QTableWidgetItem("Item (2,2)"))
    table.setItem(2,0, QTableWidgetItem("Item (3,1)"))
    table.setItem(2,1, QTableWidgetItem("Item (3,2)"))
    table.setItem(3,0, QTableWidgetItem("Item (4,1)"))
    table.setItem(3,1, QTableWidgetItem("Item (4,2)"))
    
    # show table
    table.show()
    return app.exec_()

if __name__ == '__main__':
    main()

Result:

PyQT Table PyQT Table

QTableWidget click events


We can detect cell clicks using this procedure, first add a function:

# on click function
table.cellClicked.connect(cellClick)



Then define the function:

def cellClick(row,col):
print "Click on " + str(row) + " " + str(col)

The Python programming language starts counting with 0, so when you press on (1,1) you will see (0,0). Full code to detect table clicks:

from PyQt4.QtGui import *
from PyQt4.QtCore import *
import sys

def cellClick(row,col):
    print "Click on " + str(row) + " " + str(col)

def main():
    app 	= QApplication(sys.argv)
    table 	= QTableWidget()
    tableItem 	= QTableWidgetItem()

    # initiate table
    table.setWindowTitle("QTableWidget Example @pythonspot.com")
    table.resize(400, 250)
    table.setRowCount(4)
    table.setColumnCount(2)
    
    # set label
    table.setHorizontalHeaderLabels(QString("H1;H2;").split(";"))
    table.setVerticalHeaderLabels(QString("V1;V2;V3;V4").split(";"))
    
    # set data
    table.setItem(0,0, QTableWidgetItem("Item (1,1)"))
    table.setItem(0,1, QTableWidgetItem("Item (1,2)"))
    table.setItem(1,0, QTableWidgetItem("Item (2,1)"))
    table.setItem(1,1, QTableWidgetItem("Item (2,2)"))
    table.setItem(2,0, QTableWidgetItem("Item (3,1)"))
    table.setItem(2,1, QTableWidgetItem("Item (3,2)"))
    table.setItem(3,0, QTableWidgetItem("Item (4,1)"))
    table.setItem(3,1, QTableWidgetItem("Item (4,2)"))
    
    # on click function
    table.cellClicked.connect(cellClick)
    
    # show table
    table.show()
    return app.exec_()

if __name__ == '__main__':
    main()

If you want to show the cell/row numbers in a non-programmer way use this instead:

def cellClick(row,col):
print "Click on " + str(row+1) + " " + str(col+1)



Tooltip text


We can set tooltip (mouse over) text using the method. If you set tooltips on non-existing columns you will get an error.

from PyQt4.QtGui import *
from PyQt4.QtCore import *
import sys

def main():
    app 	= QApplication(sys.argv)
    table 	= QTableWidget()
    tableItem 	= QTableWidgetItem()
    
    # initiate table
    table.setWindowTitle("QTableWidget Example @pythonspot.com")
    table.resize(400, 250)
    table.setRowCount(4)
    table.setColumnCount(2)
    
    # set label
    table.setHorizontalHeaderLabels(QString("H1;H2;").split(";"))
    table.setVerticalHeaderLabels(QString("V1;V2;V3;V4").split(";"))
    
    # set data
    table.setItem(0,0, QTableWidgetItem("Item (1,1)"))
    table.setItem(0,1, QTableWidgetItem("Item (1,2)"))
    table.setItem(1,0, QTableWidgetItem("Item (2,1)"))
    table.setItem(1,1, QTableWidgetItem("Item (2,2)"))
    table.setItem(2,0, QTableWidgetItem("Item (3,1)"))
    table.setItem(2,1, QTableWidgetItem("Item (3,2)"))
    table.setItem(3,0, QTableWidgetItem("Item (4,1)"))
    table.setItem(3,1, QTableWidgetItem("Item (4,2)"))
    
    # tooltip text
    table.horizontalHeaderItem(0).setToolTip("Column 1 ")
    table.horizontalHeaderItem(1).setToolTip("Column 2 ")
    
    # show table
    table.show()
    return app.exec_()

if __name__ == '__main__':
    main()

Result:

PyQT Table tooltips PyQT Table tooltips

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pyqt tabs

Tabs are very useful in graphical applications. They appear in webbrowsers, text editors and any other apps.  To create a tabbed window, you need to call the  QTabWidget()  function.  Every tab is a QWidget() which you have seen before.  You can connect the QWidgets with the QTabWidget with the function:

tabs.addTab(tab1,"Tab 1")

where the first parameter is the tab object and the second the name that appears on the screen. We added some buttons to the first tab (QWidget).

Related course:

Example code:

from PyQt4 import QtGui
from PyQt4 import QtCore
import sys

def main():

    app 	= QtGui.QApplication(sys.argv)
    tabs	= QtGui.QTabWidget()
    
    # Create tabs
    tab1	= QtGui.QWidget()
    tab2	= QtGui.QWidget()
    tab3	= QtGui.QWidget()
    tab4	= QtGui.QWidget()
    
    # Resize width and height
    tabs.resize(250, 150)

    # Set layout of first tab
    vBoxlayout	= QtGui.QVBoxLayout()
    pushButton1 = QtGui.QPushButton("Start")
    pushButton2 = QtGui.QPushButton("Settings")
    pushButton3 = QtGui.QPushButton("Stop")
    vBoxlayout.addWidget(pushButton1)
    vBoxlayout.addWidget(pushButton2)
    vBoxlayout.addWidget(pushButton3)
    tab1.setLayout(vBoxlayout)
    
    # Add tabs
    tabs.addTab(tab1,"Tab 1")
    tabs.addTab(tab2,"Tab 2")
    tabs.addTab(tab3,"Tab 3")
    tabs.addTab(tab4,"Tab 4")
    
    # Set title and show
    tabs.setWindowTitle('PyQt QTabWidget @ pythonspot.com')
    tabs.show()
    
    sys.exit(app.exec_())

if __name__ == '__main__':
    main()

Result:

PyQT Tabs PyQT Tabs

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pyqt display image

In this article we will demonstrate how to load and display images in an PyQT window. We can display images in a PyQT window using the Pixmap widget.

PyQt4-load-image An image loaded in a PyQt4 window.

Related course:

Introduction


The constructor of Pixmap takes the image path as parameter:

pixmap = QPixmap(os.getcwd() + '/logo.png')

This image needs to be in the same directory as your program. The QPixmap widget supports png and jpeg.  Example code below.

PyQT load image in Pixmap


We create a standard QWidget as we have done before. Then we add the QPixmap widget inside which will load the image. The Pixmap is attached to a label which is drawn to the screen.

import os
import sys
from PyQt4.QtGui import *

# Create window
app = QApplication(sys.argv)
w = QWidget()
w.setWindowTitle("PyQT4 Pixmap @ pythonspot.com ")

# Create widget
label = QLabel(w)
pixmap = QPixmap(os.getcwd() + '/logo.png')
label.setPixmap(pixmap)
w.resize(pixmap.width(),pixmap.height())

# Draw window
w.show()
app.exec_()

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Result:

pyqt Pixmap pyqt Pixmap

progressbar python

In this article we will demonstrate how to use the progressbar widget.  The progressbar is different from the other widgets in that it updates in time.

Related course:

QT4 Progressbar Example
Let’s start with the code:

#! /usr/bin/env python
# -*- coding: utf-8 -*-
#
import sys
from PyQt4.QtGui import *
from PyQt4.QtCore import *
from PyQt4.QtCore import pyqtSlot,SIGNAL,SLOT

class QProgBar(QProgressBar):

    value = 0

    @pyqtSlot()
    def increaseValue(progressBar):
        progressBar.setValue(progressBar.value)
        progressBar.value = progressBar.value+1

# Create an PyQT4 application object.
a = QApplication(sys.argv)

# The QWidget widget is the base class of all user interface objects in PyQt4.
w = QWidget()

# Set window size.
w.resize(320, 240)

# Set window title
w.setWindowTitle("PyQT4 Progressbar @ pythonspot.com ")

# Create progressBar.
bar = QProgBar(w)
bar.resize(320,50)
bar.setValue(0)
bar.move(0,20)

# create timer for progressBar
timer = QTimer()
bar.connect(timer,SIGNAL("timeout()"),bar,SLOT("increaseValue()"))
timer.start(400)

# Show window
w.show()

sys.exit(a.exec_())

The instance bar (of class QProgBar) is used to hold the value of the progressbar.  We call the function setValue() to update its value.  The parameter w is given to attach it to the main window. We then move it to position (0,20) on the screen and give it a width and height.

To update the progressbar in time we need a QTimer().  We connect the widget with the timer, which calls the function increaseValue().  We set the timer to repeat the function call every 400 milliseconds.  You also see the words SLOT and SIGNAL.  If a user does an action such as clicking on a button, typing text in a box - the widget sends out a signal.  This signal does nothing, but it can be used to connect with a slot, that acts as a receiver and acts on it.

Result:

PyQT Progressbar PyQT Progressbar

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