Calculator/main.py at main · AaronBeier/Calculator · GitHub

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from math import floor
from sys import exit
from PySide6.QtCore import Qt
from PySide6.QtGui import QFont
from PySide6.QtWidgets import QApplication, QGridLayout, QLabel, QPushButton, QSizePolicy, QVBoxLayout, QWidget

class ButtonGrid(QWidget):
	def __init__(self):
		super().__init__()

		self.layout = QGridLayout()

		positions = [(y, x) for y in range(5) for x in range(4)]
		buttons = [ # 4x5   =>   X = 4, Y = 5 but we need to switch the numbers because of the order of the loop
			'C', '/', '*', '-',
			'7', '8', '9', '+',
			'4', '5', '6', ' ',
			'1', '2', '3', '=',
			'0', ' ', '.', ' '
		]

		font = None

		# zip returns an interator of tuples based on the two input iterables
		for position, text in zip(positions, buttons):
			if text == ' ':
				continue

			button = QPushButton(text)
			if font is None:
				font = button.font()
				font.setPointSizeF(floor(font.pointSizeF() * 1.5))

			# Horizontal is Minimum by default, but we need to set Vertical to Minimum too,
			# so the button gets taller and doesn't just center between the rows
			button.setSizePolicy(QSizePolicy.Policy.Minimum, QSizePolicy.Policy.Minimum)
			button.setFont(font)

			if text in '+=': # The + and = Buttons need to be 1 cell wide and 2 cells tall
				self.layout.addWidget(button, position[0], position[1], 2, 1)

			elif text in '0': # The 0 Button needs to be 2 cells wide and 1 cell tall
				self.layout.addWidget(button, position[0], position[1], 1, 2)

			else: # All other buttons are just 1x1 on the Grid
				self.layout.addWidget(button, position[0], position[1])

		self.setLayout(self.layout)

class Calculator(QWidget):
	def __init__(self):
		super().__init__()

		self.setWindowTitle('Calculator')
		self.setMinimumSize(360, 300)
		self.setMaximumSize(360, 500)
		self.resize(360, 360)

		self.layout = QVBoxLayout()

		self.label_font = QFont('nonexistant') # Get the default Monospace Font - https://forum.qt.io/post/208937
		self.label_font.setStyleHint(QFont.Monospace)
		self.label_font.setPointSizeF(self.label_font.pointSizeF() * 2) # Double the size

		self.input_label = QLabel('')
		self.input_label.setFont(self.label_font)
		self.input_label.setAlignment(Qt.AlignmentFlag.AlignRight)
		# For labels we need to set Horizontal to Fixed so that the label only takes up the space that it needs
		# Preferred is the default for both Horizontal and Vertical
		self.input_label.setSizePolicy(QSizePolicy.Policy.Preferred, QSizePolicy.Policy.Fixed)
		self.layout.addWidget(self.input_label)

		self.result_label = QLabel('0')
		self.result_label.setFont(self.label_font)
		self.result_label.setAlignment(Qt.AlignmentFlag.AlignRight)
		self.result_label.setSizePolicy(QSizePolicy.Policy.Preferred, QSizePolicy.Policy.Fixed)
		self.layout.addWidget(self.result_label)

		self.button_grid = ButtonGrid()
		self.layout.addWidget(self.button_grid)

		self.setLayout(self.layout)

		self.input = ''
		self.result = 0
		self.operator = None
		self.errored = False

		for button in self.button_grid.findChildren(QPushButton):
			button.clicked.connect(self.button_clicked)

	def update_labels(self):
		self.input_label.setText(str(self.input))
		self.result_label.setText(str(self.result))

	def button_clicked(self):
		label = self.sender().text()

		if label == 'C':
			self.input = ''
			self.result = 0
			self.operator = None
			self.update_labels()
			self.errored = False

		if self.errored:
			return

		if label in '0123456789':
			self.input += label
			self.update_labels()

		elif label in '+-*/':
			if self.input:
				self.calculate()
				self.operator = label
				self.input = ''

		elif label == '=':
			self.calculate()
			self.operator = None
			self.input = str(self.result)

		elif label == '.':
			if '.' not in self.input:
				self.input += label
				self.update_labels()

	def calculate(self):
		if self.input:
			number = float(self.input)

			if self.operator == '+':
				self.result += number

			elif self.operator == '-':
				self.result -= number

			elif self.operator == '*':
				self.result *= number

			elif self.operator == '/':
				if number != 0:
					self.result /= number

				else:
					self.result = 'Error'
					self.errored = True

			else:
				self.result = number

			self.update_labels()

if __name__ == "__main__":
	application = QApplication([])
	window = Calculator()
	window.show()

	exit(application.exec())