Question

How to do the same in PyQt4 as the function in this youtube video tutorial.

There is a code but I need on pressed button digit to write the digit in a QlineEdit – for example as in this calculator:

#!/usr/bin/python
# -*- coding: utf-8 -*-

import sys
from PyQt4 import QtGui, QtCore

class Example(QtGui.QWidget):
    def __init__(self):
        super(Example, self).__init__()
        self.initUI()

    def initUI(self):
        numbers = [ '7', '8', '9',
            '4', '5', '6',
            '1', '2', '3',
                    '*', '0', '#',]
        grid = QtGui.QGridLayout()
        j = 0
        pos = [(0, 0), (0, 1), (0, 2),
                (1, 0), (1, 1), (1, 2),
                (2, 0), (2, 1), (2, 2),
                (3, 0), (3, 1), (3, 2),
              ]
        for i in numbers:
            button = QtGui.QPushButton(i)
            grid.addWidget(button, pos[j][0], pos[j][1])
            j = j + 1
        self.setLayout(grid)   
        self.move(300, 150)
        self.setWindowTitle('Calculator')    
        self.show()

def main():
    app = QtGui.QApplication(sys.argv)
    ex = Example()
    sys.exit(app.exec_())

if __name__ == '__main__':
    main()

Answer 1

You need to connect the button to a click event and here is the updated code which works like that video 🙂

#!/usr/bin/python
# -*- coding: utf-8 -*-

import sys
from functools import partial
from PyQt4 import QtGui, QtCore

class Example(QtGui.QWidget):
    def __init__(self):
        super(Example, self).__init__()
        self.initUI()

    def initUI(self):
        numbers = [ '7', '8', '9',
            '4', '5', '6',
            '1', '2', '3',
                    '*', '0', '#',]
        self.vert_lay = QtGui.QVBoxLayout()
        self.dig_out = QtGui.QLineEdit()
        self.vert_lay.addWidget(self.dig_out)
        grid = QtGui.QGridLayout()
        j = 0
        pos = [(0, 0), (0, 1), (0, 2),
                (1, 0), (1, 1), (1, 2),
                (2, 0), (2, 1), (2, 2),
                (3, 0), (3, 1), (3, 2),
              ]
        for i in numbers:
            button = QtGui.QPushButton(i)
            grid.addWidget(button, pos[j][0], pos[j][1])
            j = j + 1
            button.clicked.connect(partial(self.addNumber,i))

        self.vert_lay.addLayout(grid)
        self.setLayout(self.vert_lay)  

        self.move(300, 150)
        self.setWindowTitle('Calculator')    
        self.show()

    def addNumber(self,num):
        current_txt = self.dig_out.text()
        self.dig_out.setText("%s%s" % (current_txt,num))

def main():
    app = QtGui.QApplication(sys.argv)
    ex = Example()
    sys.exit(app.exec_())

if __name__ == '__main__':
    main()