A better example that works with negative numbers and floats and when the enter key is pressed it does the calculation.
Code:
#!/usr/bin/python3
import sys
from PyQt5.QtWidgets import (QApplication, QMainWindow, QLineEdit,
QVBoxLayout, QLabel, QWidget, QFrame)
from PyQt5.QtGui import QIcon
class Window(QMainWindow):
def __init__(self):
super().__init__()
self.setGeometry(50, 50, 350, 100) # X, Y, Width, Height
self.setWindowTitle("PyQT5 Math Example!")
central_widget = QWidget() # define central widget
layout = QVBoxLayout() # define layout
self.entry = QLineEdit()
layout.addWidget(self.entry)
self.lbl = QLabel(self)
self.lbl.setFrameShape(QFrame.Box)
self.lbl.setText('Enter a Simple Equation')
layout.addWidget(self.lbl)
central_widget.setLayout(layout) # add layout to central widget
self.setCentralWidget(central_widget) # set QMainWindow layout
# do the calc function when enter is pressed
self.entry.returnPressed.connect(self.calc)
self.show() # show the window
def calc(self):
equation = self.entry.text()
if '+' in equation:
y = equation.split('+')
x = self.str2number(y[0])+self.str2number(y[1])
elif '-' in equation:
y = equation.split('-')
x = self.str2number(y[0])-self.str2number(y[1])
elif '/' in equation:
y = equation.split('/')
x = self.str2number(y[0])/self.str2number(y[1])
elif '*' in equation:
y = equation.split('*')
x = self.str2number(y[0])*self.str2number(y[1])
else:
x = 'Invalid Equation'
self.lbl.setText(str(x))
def str2number(self, num):
if num.isdigit():
return int(num)
elif num.startswith('-') and num[1:].isdigit():
return int(num)
else:
return float(num)
if __name__ == '__main__':
app = QApplication(sys.argv)
GUI = Window()
sys.exit(app.exec_())
