Merge pull request #292 from realpython/python-pyqt-tutorial-update

Update sample code PyQt Calculator

Author: KateFinegan

pyqt-calculator-tutorial/README.md

@@ -0,0 +1,10 @@
+# Python and PyQt: Building a GUI Desktop Calculator
+
+This folder provides the code examples for the article [Python and PyQt: Building a GUI Desktop Calculator](https://realpython.com/python-and-pyqt-building-a-gui-desktop-calculator/).
+
+## Folder Content
+
+The current folder, `pyqt-calculator-tutorial/`, hosts two subfolders:
+
+1. `examples/` contains the source file of every example in the tutorial.
+2. `pycalc/` stores the code and related resources for your PyQt Calculator app.

pyqt-calculator-tutorial/examples/dialog.py

@@ -1,39 +1,39 @@
-# Filename: dialog.py
-
-"""Dialog-Style application."""
+"""Dialog-style application."""
 
 import sys
 
-from PyQt5.QtWidgets import QApplication
-from PyQt5.QtWidgets import QDialog
-from PyQt5.QtWidgets import QDialogButtonBox
-from PyQt5.QtWidgets import QFormLayout
-from PyQt5.QtWidgets import QLineEdit
-from PyQt5.QtWidgets import QVBoxLayout
-
+from PyQt6.QtWidgets import (
+    QApplication,
+    QDialog,
+    QDialogButtonBox,
+    QFormLayout,
+    QLineEdit,
+    QVBoxLayout,
+)
 
-class Dialog(QDialog):
-    """Dialog."""
 
-    def __init__(self, parent=None):
-        """Initializer."""
-        super().__init__(parent)
+class Window(QDialog):
+    def __init__(self):
+        super().__init__(parent=None)
         self.setWindowTitle("QDialog")
-        dlgLayout = QVBoxLayout()
+        dialogLayout = QVBoxLayout()
         formLayout = QFormLayout()
         formLayout.addRow("Name:", QLineEdit())
         formLayout.addRow("Age:", QLineEdit())
         formLayout.addRow("Job:", QLineEdit())
         formLayout.addRow("Hobbies:", QLineEdit())
-        dlgLayout.addLayout(formLayout)
-        btns = QDialogButtonBox()
-        btns.setStandardButtons(QDialogButtonBox.Cancel | QDialogButtonBox.Ok)
-        dlgLayout.addWidget(btns)
-        self.setLayout(dlgLayout)
+        dialogLayout.addLayout(formLayout)
+        buttons = QDialogButtonBox()
+        buttons.setStandardButtons(
+            QDialogButtonBox.StandardButton.Cancel
+            | QDialogButtonBox.StandardButton.Ok
+        )
+        dialogLayout.addWidget(buttons)
+        self.setLayout(dialogLayout)
 
 
 if __name__ == "__main__":
-    app = QApplication(sys.argv)
-    dlg = Dialog()
-    dlg.show()
-    sys.exit(app.exec_())
+    app = QApplication([])
+    window = Window()
+    window.show()
+    sys.exit(app.exec())

pyqt-calculator-tutorial/examples/f_layout.py

@@ -1,22 +1,19 @@
-# Filename: f_layout.py
-
 """Form layout example."""
 
 import sys
 
-from PyQt5.QtWidgets import QApplication
-from PyQt5.QtWidgets import QFormLayout
-from PyQt5.QtWidgets import QLineEdit
-from PyQt5.QtWidgets import QWidget
+from PyQt6.QtWidgets import QApplication, QFormLayout, QLineEdit, QWidget
 
-app = QApplication(sys.argv)
+app = QApplication([])
 window = QWidget()
 window.setWindowTitle("QFormLayout")
+
 layout = QFormLayout()
 layout.addRow("Name:", QLineEdit())
 layout.addRow("Age:", QLineEdit())
 layout.addRow("Job:", QLineEdit())
 layout.addRow("Hobbies:", QLineEdit())
 window.setLayout(layout)
+
 window.show()
-sys.exit(app.exec_())
+sys.exit(app.exec())

pyqt-calculator-tutorial/examples/g_layout.py

@@ -1,17 +1,13 @@
-# Filename: g_layout.py
-
 """Grid layout example."""
 
 import sys
 
-from PyQt5.QtWidgets import QApplication
-from PyQt5.QtWidgets import QGridLayout
-from PyQt5.QtWidgets import QPushButton
-from PyQt5.QtWidgets import QWidget
+from PyQt6.QtWidgets import QApplication, QGridLayout, QPushButton, QWidget
 
-app = QApplication(sys.argv)
+app = QApplication([])
 window = QWidget()
 window.setWindowTitle("QGridLayout")
+
 layout = QGridLayout()
 layout.addWidget(QPushButton("Button (0, 0)"), 0, 0)
 layout.addWidget(QPushButton("Button (0, 1)"), 0, 1)
@@ -22,5 +18,6 @@
 layout.addWidget(QPushButton("Button (2, 0)"), 2, 0)
 layout.addWidget(QPushButton("Button (2, 1) + 2 Columns Span"), 2, 1, 1, 2)
 window.setLayout(layout)
+
 window.show()
-sys.exit(app.exec_())
+sys.exit(app.exec())

pyqt-calculator-tutorial/examples/h_layout.py

@@ -1,21 +1,18 @@
-# Filename: h_layout.py
-
 """Horizontal layout example."""
 
 import sys
 
-from PyQt5.QtWidgets import QApplication
-from PyQt5.QtWidgets import QHBoxLayout
-from PyQt5.QtWidgets import QPushButton
-from PyQt5.QtWidgets import QWidget
+from PyQt6.QtWidgets import QApplication, QHBoxLayout, QPushButton, QWidget
 
-app = QApplication(sys.argv)
+app = QApplication([])
 window = QWidget()
 window.setWindowTitle("QHBoxLayout")
+
 layout = QHBoxLayout()
 layout.addWidget(QPushButton("Left"))
 layout.addWidget(QPushButton("Center"))
 layout.addWidget(QPushButton("Right"))
 window.setLayout(layout)
+
 window.show()
-sys.exit(app.exec_())
+sys.exit(app.exec())

pyqt-calculator-tutorial/examples/hello.py

@@ -1,27 +1,29 @@
-# Filename: hello.py
-
-"""Simple Hello World example with PyQt5."""
+"""Simple Hello, World example with PyQt6."""
 
 import sys
 
-# 1. Import `QApplication` and all the required widgets
-from PyQt5.QtWidgets import QApplication
-from PyQt5.QtWidgets import QLabel
-from PyQt5.QtWidgets import QWidget
+# 1. Import QApplication, and all the required widgets
+from PyQt6.QtWidgets import QApplication, QLabel, QWidget
+
+WIN_X = 100
+WIN_Y = 100
+WIDTH = 280
+HEIGHT = 80
+LABEL_X = 60
+LABEL_Y = 15
 
 # 2. Create an instance of QApplication
 app = QApplication(sys.argv)
 
 # 3. Create an instance of your application's GUI
 window = QWidget()
-window.setWindowTitle("PyQt5 App")
-window.setGeometry(100, 100, 280, 80)
-window.move(60, 15)
-helloMsg = QLabel("<h1>Hello World!</h1>", parent=window)
-helloMsg.move(60, 15)
+window.setWindowTitle("PyQt App")
+window.setGeometry(WIN_X, WIN_Y, WIDTH, HEIGHT)
+helloMsg = QLabel("<h1>Hello, World!</h1>", parent=window)
+helloMsg.move(LABEL_X, LABEL_Y)
 
 # 4.Show your application's GUI
 window.show()
 
-# 5. Run your application's event loop (or main loop)
-sys.exit(app.exec_())
+# 5. Run your application's event loop
+sys.exit(app.exec())

pyqt-calculator-tutorial/examples/main_window.py

@@ -1,31 +1,28 @@
-# Filename: main_window.py
-
-"""Main Window-Style application."""
+"""Main window-style application."""
 
 import sys
 
-from PyQt5.QtWidgets import QApplication
-from PyQt5.QtWidgets import QLabel
-from PyQt5.QtWidgets import QMainWindow
-from PyQt5.QtWidgets import QStatusBar
-from PyQt5.QtWidgets import QToolBar
+from PyQt6.QtWidgets import (
+    QApplication,
+    QLabel,
+    QMainWindow,
+    QStatusBar,
+    QToolBar,
+)
 
 
 class Window(QMainWindow):
-    """Main Window."""
-
-    def __init__(self, parent=None):
-        """Initializer."""
-        super().__init__(parent)
+    def __init__(self):
+        super().__init__(parent=None)
         self.setWindowTitle("QMainWindow")
         self.setCentralWidget(QLabel("I'm the Central Widget"))
         self._createMenu()
         self._createToolBar()
         self._createStatusBar()
 
     def _createMenu(self):
-        self.menu = self.menuBar().addMenu("&Menu")
-        self.menu.addAction("&Exit", self.close)
+        menu = self.menuBar().addMenu("&Menu")
+        menu.addAction("&Exit", self.close)
 
     def _createToolBar(self):
         tools = QToolBar()
@@ -39,7 +36,7 @@ def _createStatusBar(self):
 
 
 if __name__ == "__main__":
-    app = QApplication(sys.argv)
-    win = Window()
-    win.show()
-    sys.exit(app.exec_())
+    app = QApplication([])
+    window = Window()
+    window.show()
+    sys.exit(app.exec())

pyqt-calculator-tutorial/examples/signal_slots.py

@@ -0,0 +1,34 @@
+"""Signals and slots example."""
+
+import sys
+
+from PyQt6.QtWidgets import (
+    QApplication,
+    QLabel,
+    QPushButton,
+    QVBoxLayout,
+    QWidget,
+)
+
+
+def greet():
+    if msgLabel.text():
+        msgLabel.setText("")
+    else:
+        msgLabel.setText("Hello World!")
+
+
+app = QApplication([])
+window = QWidget()
+window.setWindowTitle("Signals and slots")
+layout = QVBoxLayout()
+
+button = QPushButton("Greet")
+button.clicked.connect(greet)
+
+layout.addWidget(button)
+msgLabel = QLabel("")
+layout.addWidget(msgLabel)
+window.setLayout(layout)
+window.show()
+sys.exit(app.exec())