calculator.py

import sys
import re
from PyQt5.QtWidgets import QApplication, QVBoxLayout, QGridLayout, QPushButton, QLabel, QTextEdit
from PyQt5.QtWidgets import QWidget
from PyQt5.QtCore import Qt
from Addition import AddCollection
from Subtraction import SubCollection
from multiply import MultiplyCollection
from division import DivideCollection
class Calculator(QWidget):
    
	# Method for initializing the UI and calculator functionalities
    def __init__(self):
        super().__init__()
        self.result_display = None
        self.result_str = ''
        self.create_ui()

    # Method for creating the calculator UI
    def create_ui(self):
        self.setWindowTitle('Calculator')
        vBoxLayout = QVBoxLayout()
        gridLayout = QGridLayout()

        button_txt_list = [["C", "^", "%", "/"],
                           ["7", "8", "9", "*"],
                           ["4", "5", "6", "-"],
                           ["1", "2", "3", "+"],
                           [ "0", ".", "="]]
        button_list = []
        for row in range(5):
            button_row_list = []
            for col, button_txt in enumerate(button_txt_list[row]):
                button = QPushButton(button_txt)
                button_row_list.append(button)
                gridLayout.addWidget(button, row, col)
                button.clicked.connect(self.button_clicked)
            button_list.append(button_row_list)

        self.result_display = QTextEdit()
        vBoxLayout.addWidget(self.result_display)
        vBoxLayout.addLayout(gridLayout)
        self.result_display.setFixedHeight(30)
        self.result_display.setFontPointSize(14)
        self.result_display.setText("0")
        self.result_display.setAlignment(Qt.AlignRight)
        self.result_display.setReadOnly(True)
        # self.result_display.setDisabled(True)

        self.setLayout(vBoxLayout)
        self.show()

    # Method for creating the connection between UI element and the functionality
    def button_clicked(self):
        # TODO: Implement Calculator logic
        sender = self.sender()
        button_txt = sender.text()
        if button_txt == "C":
            self.result_str = ""
        elif button_txt == "=":
            num_list = re.split('\+|\-|\*|\%|\^|\/', self.result_str)
            if "+" in self.result_str:
                self.result_str = str(AddCollection(num_list))
            elif "-" in self.result_str:
                self.result_str = str(SubCollection(num_list))    
            elif "*" in self.result_str:
                self.result_str = str(MultiplyCollection(num_list))
            elif "/" in self.result_str:
                self.result_str = str(DivideCollection(num_list))
            
        else:
            self.result_str += button_txt
        self.result_display.setText(self.result_str)
        self.result_display.setAlignment(Qt.AlignRight)


if __name__ == "__main__":
    app = QApplication(sys.argv)
    calc = Calculator()
    sys.exit(app.exec_())