import sys
from PyQt5 import QtWidgets as qtw
from PyQt5 import QtGui as qtg
from PyQt5 import QtCore as qtc
class MainWindow(qtw.QWidget):
def __init__(self):
"""MainWindow constructor.
This widget will be our main window.
We'll define all the UI components in here.
"""
super().__init__()
# Main UI code goes here
self.setLayout(qtw.QVBoxLayout())
lcd = qtw.QLCDNumber(self)
self.layout().addWidget(lcd)
history = qtw.QLineEdit(self, placeholderText='History')
self.layout().addWidget(history)
button_texts = [
'Clear', 'BackSpace', 'Mem', 'Mem Clear',
'1', '2', '3', '+',
'4', '5', '6', '-',
'7', '8', '9', '×',
'.', '0', '=', '÷'
]
button_layout = qtw.QGridLayout()
self.layout().addLayout(button_layout)
buttons = []
for num, button_text in enumerate(button_texts):
button = qtw.QPushButton(button_text, self)
button.setSizePolicy(qtw.QSizePolicy.Expanding, qtw.QSizePolicy.Expanding)
buttons.append(button)
row = num // 4
column = num % 4
button_layout.addWidget(button, row, column)
# End main UI code
self.show()
if __name__ == '__main__':
app = qtw.QApplication(sys.argv)
# it's required to save a reference to MainWindow.
# if it goes out of scope, it will be destroyed.
mw = MainWindow()
sys.exit(app.exec())
