Add signals, and slots example

Author: lpozo

pyqt-calculator-tutorial/examples/signals_slots.py

@@ -0,0 +1,29 @@
+# filename: signals_slots.py
+
+"""Signals, and Slots example."""
+
+import sys
+
+from PyQt5.QtWidgets import QApplication
+from PyQt5.QtWidgets import QWidget
+from PyQt5.QtWidgets import QPushButton
+from PyQt5.QtWidgets import QLabel
+from PyQt5.QtWidgets import QVBoxLayout
+
+
+def greeting():
+    msg.setText('Hello World!')
+
+
+app = QApplication(sys.argv)
+window = QWidget()
+window.setWindowTitle('Signals, and Slots')
+layout = QVBoxLayout()
+btn = QPushButton('Greet')
+btn.clicked.connect(greeting)
+layout.addWidget(btn)
+msg = QLabel('')
+layout.addWidget(msg)
+window.setLayout(layout)
+window.show()
+sys.exit(app.exec_())