Merge branch 'master' into directroy-tree-generator

python-contact-book/README.md

+# RP Contacts
+
+**RP Contacts** is a Contact Book application built with Python, [PyQt5](https://www.riverbankcomputing.com/static/Docs/PyQt5/index.html), and [SQLite](https://www.sqlite.org/docs.html).
+
+## Running the Application
+
+To run **RP Contacts**, you need to download the source code. Then open a terminal or command-line window and run the following steps:
+
+1. Create and activate a Python virtual environment
+
+```sh
+$ cd rpcontacts/
+$ python -m venv ./venv
+$ source venv/bin/activate
+(venv) $
+```
+
+2. Install the dependencies
+
+```sh
+(venv) $ python -m pip install -r requirements.txt
+```
+
+3. Run the application
+
+```sh
+(venv) $ python rpcontacts.py
+```
+
+**Note:** This application was coded and tested using Python 3.8.5 and PyQt 5.15.2.
+
+## Release History
+
+- 0.1.0
+  - A work in progress
+
+## About the Author
+
+Leodanis Pozo Ramos – [@lpozo78](https://twitter.com/lpozo78) – leodanis@realpython.com
+
+## License
+
+Distributed under the MIT license.

python-contact-book/source_code_final/requirements.txt

+PyQt5==5.15.2

python-contact-book/source_code_final/rpcontacts.py

+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+
+"""This module provides RP Contacts entry point script."""
+
+from rpcontacts.main import main
+
+if __name__ == "__main__":
+    main()

python-contact-book/source_code_final/rpcontacts/__init__.py

+# -*- coding: utf-8 -*-
+
+"""This module provides the rpcontacts package."""
+
+__version__ = "0.1.0"

python-contact-book/source_code_final/rpcontacts/database.py

+# -*- coding: utf-8 -*-
+
+"""This module provides a database connection."""
+
+from PyQt5.QtWidgets import QMessageBox
+from PyQt5.QtSql import QSqlDatabase, QSqlQuery
+
+
+def _createContactsTable():
+    """Create the contacts table in the database."""
+    createTableQuery = QSqlQuery()
+    return createTableQuery.exec(
+        """
+        CREATE TABLE IF NOT EXISTS contacts (
+            id INTEGER PRIMARY KEY AUTOINCREMENT UNIQUE NOT NULL,
+            name VARCHAR(40) NOT NULL,
+            job VARCHAR(50),
+            email VARCHAR(40) NOT NULL
+        )
+        """
+    )
+
+
+def createConnection(databaseName):
+    """Create and open a database connection."""
+    connection = QSqlDatabase.addDatabase("QSQLITE")
+    connection.setDatabaseName(databaseName)
+
+    if not connection.open():
+        QMessageBox.warning(
+            None,
+            "RP Contact",
+            f"Database Error: {connection.lastError().text()}",
+        )
+        return False
+
+    _createContactsTable()
+    return True

python-contact-book/source_code_final/rpcontacts/main.py

+# -*- coding: utf-8 -*-
+
+"""This module provides RP Contacts application."""
+
+import sys
+
+from PyQt5.QtWidgets import QApplication
+
+from .database import createConnection
+from .views import Window
+
+
+def main():
+    """RP Contacts main function."""
+    # Create the application
+    app = QApplication(sys.argv)
+    # Connect to the database before creating any window
+    if not createConnection("contacts.sqlite"):
+        sys.exit(1)
+    # Create the main window if the connection succeeded
+    win = Window()
+    win.show()
+    # Run the event loop
+    sys.exit(app.exec_())

python-contact-book/source_code_final/rpcontacts/model.py

+# -*- coding: utf-8 -*-
+
+"""This module provides a model to manage the contacts table."""
+
+from PyQt5.QtCore import Qt
+from PyQt5.QtSql import QSqlTableModel
+
+
+class ContactsModel:
+    def __init__(self):
+        self.model = self._createModel()
+
+    @staticmethod
+    def _createModel():
+        """Create and set up the model."""
+        tableModel = QSqlTableModel()
+        tableModel.setTable("contacts")
+        tableModel.setEditStrategy(QSqlTableModel.OnFieldChange)
+        tableModel.select()
+        headers = ("ID", "Name", "Job", "Email")
+        for columnIndex, header in enumerate(headers):
+            tableModel.setHeaderData(columnIndex, Qt.Horizontal, header)
+        return tableModel
+
+    def addContact(self, data):
+        """Add a contact to the database."""
+        rows = self.model.rowCount()
+        self.model.insertRows(rows, 1)
+        for column_index, field in enumerate(data):
+            self.model.setData(self.model.index(rows, column_index + 1), field)
+        self.model.submitAll()
+        self.model.select()
+
+    def deleteContact(self, row):
+        """Remove a contact from the database."""
+        self.model.removeRow(row)
+        self.model.submitAll()
+        self.model.select()
+
+    def clearContacts(self):
+        """Remove all contacts in the database."""
+        self.model.setEditStrategy(QSqlTableModel.OnManualSubmit)
+        self.model.removeRows(0, self.model.rowCount())
+        self.model.submitAll()
+        self.model.setEditStrategy(QSqlTableModel.OnFieldChange)
+        self.model.select()

python-contact-book/source_code_final/rpcontacts/views.py

+# -*- coding: utf-8 -*-
+
+"""This module provides views to manage the contacts table."""
+
+from PyQt5.QtCore import Qt
+from PyQt5.QtWidgets import (
+    QAbstractItemView,
+    QDialog,
+    QDialogButtonBox,
+    QFormLayout,
+    QHBoxLayout,
+    QLineEdit,
+    QMainWindow,
+    QMessageBox,
+    QPushButton,
+    QTableView,
+    QVBoxLayout,
+    QWidget,
+)
+
+from .model import ContactsModel
+
+
+class Window(QMainWindow):
+    """Main Window."""
+
+    def __init__(self, parent=None):
+        """Initializer."""
+        super().__init__(parent)
+        self.setWindowTitle("RP Contacts")
+        self.resize(550, 250)
+        self.centralWidget = QWidget()
+        self.setCentralWidget(self.centralWidget)
+        self.layout = QHBoxLayout()
+        self.centralWidget.setLayout(self.layout)
+
+        self.contactsModel = ContactsModel()
+        self.setupUI()
+
+    def setupUI(self):
+        """Setup the main window's GUI."""
+        # Create the table view widget
+        self.table = QTableView()
+        self.table.setModel(self.contactsModel.model)
+        self.table.setSelectionBehavior(QAbstractItemView.SelectRows)
+        self.table.resizeColumnsToContents()
+        # Create buttons
+        self.addButton = QPushButton("Add...")
+        self.addButton.clicked.connect(self.openAddDialog)
+        self.deleteButton = QPushButton("Delete")
+        self.deleteButton.clicked.connect(self.deleteContact)
+        self.clearAllButton = QPushButton("Clear All")
+        self.clearAllButton.clicked.connect(self.clearContacts)
+        # Lay out the GUI
+        layout = QVBoxLayout()
+        layout.addWidget(self.addButton)
+        layout.addWidget(self.deleteButton)
+        layout.addStretch()
+        layout.addWidget(self.clearAllButton)
+        self.layout.addWidget(self.table)
+        self.layout.addLayout(layout)
+
+    def openAddDialog(self):
+        """Open the Add Contact dialog."""
+        dialog = AddDialog(self)
+        if dialog.exec() == QDialog.Accepted:
+            self.contactsModel.addContact(dialog.data)
+            self.table.resizeColumnsToContents()
+
+    def deleteContact(self):
+        """Delete the selected contact from the database."""
+        row = self.table.currentIndex().row()
+        if row < 0:
+            return
+
+        messageBox = QMessageBox.warning(
+            self,
+            "Warning!",
+            "Do you want to remove the selected contact?",
+            QMessageBox.Ok | QMessageBox.Cancel,
+        )
+
+        if messageBox == QMessageBox.Ok:
+            self.contactsModel.deleteContact(row)
+
+    def clearContacts(self):
+        """Remove all contacts from the database."""
+        messageBox = QMessageBox.warning(
+            self,
+            "Warning!",
+            "Do you want to remove all your contacts?",
+            QMessageBox.Ok | QMessageBox.Cancel,
+        )
+
+        if messageBox == QMessageBox.Ok:
+            self.contactsModel.clearContacts()
+
+
+class AddDialog(QDialog):
+    """Add Contact dialog."""
+
+    def __init__(self, parent=None):
+        """Initializer."""
+        super().__init__(parent=parent)
+        self.setWindowTitle("Add Contact")
+        self.layout = QVBoxLayout()
+        self.setLayout(self.layout)
+        self.data = None
+
+        self.setupUI()
+
+    def setupUI(self):
+        """Setup the Add Contact dialog's GUI."""
+        # Create line edits for data fields
+        self.nameField = QLineEdit()
+        self.nameField.setObjectName("Name")
+        self.jobField = QLineEdit()
+        self.jobField.setObjectName("Job")
+        self.emailField = QLineEdit()
+        self.emailField.setObjectName("Email")
+        # Lay out the data fields
+        layout = QFormLayout()
+        layout.addRow("Name:", self.nameField)
+        layout.addRow("Job:", self.jobField)
+        layout.addRow("Email:", self.emailField)
+        self.layout.addLayout(layout)
+        # Add standard buttons to the dialog and connect them
+        self.buttonsBox = QDialogButtonBox(self)
+        self.buttonsBox.setOrientation(Qt.Horizontal)
+        self.buttonsBox.setStandardButtons(
+            QDialogButtonBox.Ok | QDialogButtonBox.Cancel
+        )
+        self.buttonsBox.accepted.connect(self.accept)
+        self.buttonsBox.rejected.connect(self.reject)
+        self.layout.addWidget(self.buttonsBox)
+
+    def accept(self):
+        """Accept the data provided through the dialog."""
+        self.data = []
+        for field in (self.nameField, self.jobField, self.emailField):
+            if not field.text():
+                QMessageBox.critical(
+                    self,
+                    "Error!",
+                    f"You must provide a contact's {field.objectName()}",
+                )
+                self.data = None  # Reset .data
+                return
+
+            self.data.append(field.text())
+
+        if not self.data:
+            return
+
+        super().accept()

python-contact-book/source_code_step_1/rpcontacts.py

+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+
+"""This module provides RP Contacts entry point script."""
+
+from rpcontacts.main import main
+
+if __name__ == "__main__":
+    main()

python-contact-book/source_code_step_1/rpcontacts/__init__.py

+# -*- coding: utf-8 -*-
+
+"""This module provides the rpcontacts package."""
+
+__version__ = "0.1.0"

python-contact-book/source_code_step_1/rpcontacts/main.py

+# -*- coding: utf-8 -*-
+
+"""This module provides RP Contacts application."""
+
+import sys
+
+from PyQt5.QtWidgets import QApplication
+
+from .views import Window
+
+
+def main():
+    """RP Contacts main function."""
+    # Create the application
+    app = QApplication(sys.argv)
+    # Create the main window
+    win = Window()
+    win.show()
+    # Run the event loop
+    sys.exit(app.exec())

python-contact-book/source_code_step_1/rpcontacts/views.py

+# -*- coding: utf-8 -*-
+
+"""This module provides views to manage the contacts table."""
+
+from PyQt5.QtWidgets import (
+    QHBoxLayout,
+    QMainWindow,
+    QWidget,
+)
+
+
+class Window(QMainWindow):
+    """Main Window."""
+
+    def __init__(self, parent=None):
+        """Initializer."""
+        super().__init__(parent)
+        self.setWindowTitle("RP Contacts")
+        self.resize(550, 250)
+        self.centralWidget = QWidget()
+        self.setCentralWidget(self.centralWidget)
+        self.layout = QHBoxLayout()
+        self.centralWidget.setLayout(self.layout)

python-contact-book/source_code_step_2/rpcontacts.py

+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+
+"""This module provides RP Contacts entry point script."""
+
+from rpcontacts.main import main
+
+if __name__ == "__main__":
+    main()

python-contact-book/source_code_step_2/rpcontacts/__init__.py

+# -*- coding: utf-8 -*-
+
+"""This module provides the rpcontacts package."""
+
+__version__ = "0.1.0"

python-contact-book/source_code_step_2/rpcontacts/main.py

+# -*- coding: utf-8 -*-
+
+"""This module provides RP Contacts application."""
+
+import sys
+
+from PyQt5.QtWidgets import QApplication
+
+from .views import Window
+
+
+def main():
+    """RP Contacts main function."""
+    # Create the application
+    app = QApplication(sys.argv)
+    # Create the main window
+    win = Window()
+    win.show()
+    # Run the event loop
+    sys.exit(app.exec())

python-contact-book/source_code_step_2/rpcontacts/views.py

+# -*- coding: utf-8 -*-
+
+"""This module provides views to manage the contacts table."""
+
+from PyQt5.QtWidgets import (
+    QAbstractItemView,
+    QHBoxLayout,
+    QMainWindow,
+    QPushButton,
+    QTableView,
+    QVBoxLayout,
+    QWidget,
+)
+
+
+class Window(QMainWindow):
+    """Main Window."""
+
+    def __init__(self, parent=None):
+        """Initializer."""
+        super().__init__(parent)
+        self.setWindowTitle("RP Contacts")
+        self.resize(550, 250)
+        self.centralWidget = QWidget()
+        self.setCentralWidget(self.centralWidget)
+        self.layout = QHBoxLayout()
+        self.centralWidget.setLayout(self.layout)
+
+        self.setupUI()
+
+    def setupUI(self):
+        """Setup the main window's GUI."""
+        # Create the table view widget
+        self.table = QTableView()
+        self.table.setSelectionBehavior(QAbstractItemView.SelectRows)
+        self.table.resizeColumnsToContents()
+        # Create buttons
+        self.addButton = QPushButton("Add...")
+        self.deleteButton = QPushButton("Delete")
+        self.clearAllButton = QPushButton("Clear All")
+        # Lay out the GUI
+        layout = QVBoxLayout()
+        layout.addWidget(self.addButton)
+        layout.addWidget(self.deleteButton)
+        layout.addStretch()
+        layout.addWidget(self.clearAllButton)
+        self.layout.addWidget(self.table)
+        self.layout.addLayout(layout)

python-contact-book/source_code_step_3/rpcontacts.py

+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+
+"""This module provides RP Contacts entry point script."""
+
+from rpcontacts.main import main
+
+if __name__ == "__main__":
+    main()

python-contact-book/source_code_step_3/rpcontacts/__init__.py

+# -*- coding: utf-8 -*-
+
+"""This module provides the rpcontacts package."""
+
+__version__ = "0.1.0"

python-contact-book/source_code_step_3/rpcontacts/database.py

+# -*- coding: utf-8 -*-
+
+"""This module provides a database connection."""
+
+from PyQt5.QtWidgets import QMessageBox
+from PyQt5.QtSql import QSqlDatabase, QSqlQuery
+
+
+def _createContactsTable():
+    """Create the contacts table in the database."""
+    createTableQuery = QSqlQuery()
+    return createTableQuery.exec(
+        """
+        CREATE TABLE IF NOT EXISTS contacts (
+            id INTEGER PRIMARY KEY AUTOINCREMENT UNIQUE NOT NULL,
+            name VARCHAR(40) NOT NULL,
+            job VARCHAR(50),
+            email VARCHAR(40) NOT NULL
+        )
+        """
+    )
+
+
+def createConnection(databaseName):
+    """Create and open a database connection."""
+    connection = QSqlDatabase.addDatabase("QSQLITE")
+    connection.setDatabaseName(databaseName)
+
+    if not connection.open():
+        QMessageBox.warning(
+            None,
+            "RP Contact",
+            f"Database Error: {connection.lastError().text()}",
+        )
+        return False
+
+    _createContactsTable()
+    return True

python-contact-book/source_code_step_3/rpcontacts/main.py

+# -*- coding: utf-8 -*-
+
+"""This module provides RP Contacts application."""
+
+import sys
+
+from PyQt5.QtWidgets import QApplication
+
+from .database import createConnection
+from .views import Window
+
+
+def main():
+    """RP Contacts main function."""
+    # Create the application
+    app = QApplication(sys.argv)
+    # Connect to the database before creating any window
+    if not createConnection("contacts.sqlite"):
+        sys.exit(1)
+    # Create the main window if the connection succeeded
+    win = Window()
+    win.show()
+    # Run the event loop
+    sys.exit(app.exec_())

python-contact-book/source_code_step_3/rpcontacts/views.py

+# -*- coding: utf-8 -*-
+
+"""This module provides views to manage the contacts table."""
+
+from PyQt5.QtWidgets import (
+    QAbstractItemView,
+    QHBoxLayout,
+    QMainWindow,
+    QPushButton,
+    QTableView,
+    QVBoxLayout,
+    QWidget,
+)
+
+
+class Window(QMainWindow):
+    """Main Window."""
+
+    def __init__(self, parent=None):
+        """Initializer."""
+        super().__init__(parent)
+        self.setWindowTitle("RP Contacts")
+        self.resize(550, 250)
+        self.centralWidget = QWidget()
+        self.setCentralWidget(self.centralWidget)
+        self.layout = QHBoxLayout()
+        self.centralWidget.setLayout(self.layout)
+
+        self.setupUI()
+
+    def setupUI(self):
+        """Setup the main window's GUI."""
+        # Create the table view widget
+        self.table = QTableView()
+        self.table.setSelectionBehavior(QAbstractItemView.SelectRows)
+        self.table.resizeColumnsToContents()
+        # Create buttons
+        self.addButton = QPushButton("Add...")
+        self.deleteButton = QPushButton("Delete")
+        self.clearAllButton = QPushButton("Clear All")
+        # Lay out the GUI
+        layout = QVBoxLayout()
+        layout.addWidget(self.addButton)
+        layout.addWidget(self.deleteButton)
+        layout.addStretch()
+        layout.addWidget(self.clearAllButton)
+        self.layout.addWidget(self.table)
+        self.layout.addLayout(layout)

python-contact-book/source_code_step_4/rpcontacts.py

+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+
+"""This module provides RP Contacts entry point script."""
+
+from rpcontacts.main import main
+
+if __name__ == "__main__":
+    main()

python-contact-book/source_code_step_4/rpcontacts/__init__.py

+# -*- coding: utf-8 -*-
+
+"""This module provides the rpcontacts package."""
+
+__version__ = "0.1.0"

python-contact-book/source_code_step_4/rpcontacts/database.py

+# -*- coding: utf-8 -*-
+
+"""This module provides a database connection."""
+
+from PyQt5.QtWidgets import QMessageBox
+from PyQt5.QtSql import QSqlDatabase, QSqlQuery
+
+
+def _createContactsTable():
+    """Create the contacts table in the database."""
+    createTableQuery = QSqlQuery()
+    return createTableQuery.exec(
+        """
+        CREATE TABLE IF NOT EXISTS contacts (
+            id INTEGER PRIMARY KEY AUTOINCREMENT UNIQUE NOT NULL,
+            name VARCHAR(40) NOT NULL,
+            job VARCHAR(50),
+            email VARCHAR(40) NOT NULL
+        )
+        """
+    )
+
+
+def createConnection(databaseName):
+    """Create and open a database connection."""
+    connection = QSqlDatabase.addDatabase("QSQLITE")
+    connection.setDatabaseName(databaseName)
+
+    if not connection.open():
+        QMessageBox.warning(
+            None,
+            "RP Contact",
+            f"Database Error: {connection.lastError().text()}",
+        )
+        return False
+
+    _createContactsTable()
+    return True

python-contact-book/source_code_step_4/rpcontacts/main.py

+# -*- coding: utf-8 -*-
+
+"""This module provides RP Contacts application."""
+
+import sys
+
+from PyQt5.QtWidgets import QApplication
+
+from .database import createConnection
+from .views import Window
+
+
+def main():
+    """RP Contacts main function."""
+    # Create the application
+    app = QApplication(sys.argv)
+    # Connect to the database before creating any window
+    if not createConnection("contacts.sqlite"):
+        sys.exit(1)
+    # Create the main window if the connection succeeded
+    win = Window()
+    win.show()
+    # Run the event loop
+    sys.exit(app.exec_())

python-contact-book/source_code_step_4/rpcontacts/model.py

+# -*- coding: utf-8 -*-
+
+"""This module provides a model to manage the contacts table."""
+
+from PyQt5.QtCore import Qt
+from PyQt5.QtSql import QSqlTableModel
+
+
+class ContactsModel:
+    def __init__(self):
+        self.model = self._createModel()
+
+    @staticmethod
+    def _createModel():
+        """Create and set up the model."""
+        tableModel = QSqlTableModel()
+        tableModel.setTable("contacts")
+        tableModel.setEditStrategy(QSqlTableModel.OnFieldChange)
+        tableModel.select()
+        headers = ("ID", "Name", "Job", "Email")
+        for columnIndex, header in enumerate(headers):
+            tableModel.setHeaderData(columnIndex, Qt.Horizontal, header)
+        return tableModel

python-contact-book/source_code_step_4/rpcontacts/views.py

+# -*- coding: utf-8 -*-
+
+"""This module provides views to manage the contacts table."""
+
+from PyQt5.QtWidgets import (
+    QAbstractItemView,
+    QHBoxLayout,
+    QMainWindow,
+    QPushButton,
+    QTableView,
+    QVBoxLayout,
+    QWidget,
+)
+
+from .model import ContactsModel
+
+
+class Window(QMainWindow):
+    """Main Window."""
+
+    def __init__(self, parent=None):
+        """Initializer."""
+        super().__init__(parent)
+        self.setWindowTitle("RP Contacts")
+        self.resize(550, 250)
+        self.centralWidget = QWidget()
+        self.setCentralWidget(self.centralWidget)
+        self.layout = QHBoxLayout()
+        self.centralWidget.setLayout(self.layout)
+
+        self.contactsModel = ContactsModel()
+        self.setupUI()
+
+    def setupUI(self):
+        """Setup the main window's GUI."""
+        # Create the table view widget
+        self.table = QTableView()
+        self.table.setModel(self.contactsModel.model)
+        self.table.setSelectionBehavior(QAbstractItemView.SelectRows)
+        self.table.resizeColumnsToContents()
+        # Create buttons
+        self.addButton = QPushButton("Add...")
+        self.deleteButton = QPushButton("Delete")
+        self.clearAllButton = QPushButton("Clear All")
+        # Lay out the GUI
+        layout = QVBoxLayout()
+        layout.addWidget(self.addButton)
+        layout.addWidget(self.deleteButton)
+        layout.addStretch()
+        layout.addWidget(self.clearAllButton)
+        self.layout.addWidget(self.table)
+        self.layout.addLayout(layout)

python-contact-book/source_code_step_5/rpcontacts.py

+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+
+"""This module provides RP Contacts entry point script."""
+
+from rpcontacts.main import main
+
+if __name__ == "__main__":
+    main()

python-contact-book/source_code_step_5/rpcontacts/__init__.py

+# -*- coding: utf-8 -*-
+
+"""This module provides the rpcontacts package."""
+
+__version__ = "0.1.0"

python-contact-book/source_code_step_5/rpcontacts/database.py

+# -*- coding: utf-8 -*-
+
+"""This module provides a database connection."""
+
+from PyQt5.QtWidgets import QMessageBox
+from PyQt5.QtSql import QSqlDatabase, QSqlQuery
+
+
+def _createContactsTable():
+    """Create the contacts table in the database."""
+    createTableQuery = QSqlQuery()
+    return createTableQuery.exec(
+        """
+        CREATE TABLE IF NOT EXISTS contacts (
+            id INTEGER PRIMARY KEY AUTOINCREMENT UNIQUE NOT NULL,
+            name VARCHAR(40) NOT NULL,
+            job VARCHAR(50),
+            email VARCHAR(40) NOT NULL
+        )
+        """
+    )
+
+
+def createConnection(databaseName):
+    """Create and open a database connection."""
+    connection = QSqlDatabase.addDatabase("QSQLITE")
+    connection.setDatabaseName(databaseName)
+
+    if not connection.open():
+        QMessageBox.warning(
+            None,
+            "RP Contact",
+            f"Database Error: {connection.lastError().text()}",
+        )
+        return False
+
+    _createContactsTable()
+    return True

python-contact-book/source_code_step_5/rpcontacts/main.py

+# -*- coding: utf-8 -*-
+
+"""This module provides RP Contacts application."""
+
+import sys
+
+from PyQt5.QtWidgets import QApplication
+
+from .database import createConnection
+from .views import Window
+
+
+def main():
+    """RP Contacts main function."""
+    # Create the application
+    app = QApplication(sys.argv)
+    # Connect to the database before creating any window
+    if not createConnection("contacts.sqlite"):
+        sys.exit(1)
+    # Create the main window if the connection succeeded
+    win = Window()
+    win.show()
+    # Run the event loop
+    sys.exit(app.exec_())

python-contact-book/source_code_step_5/rpcontacts/model.py

+# -*- coding: utf-8 -*-
+
+"""This module provides a model to manage the contacts table."""
+
+from PyQt5.QtCore import Qt
+from PyQt5.QtSql import QSqlTableModel
+
+
+class ContactsModel:
+    def __init__(self):
+        self.model = self._createModel()
+
+    @staticmethod
+    def _createModel():
+        """Create and set up the model."""
+        tableModel = QSqlTableModel()
+        tableModel.setTable("contacts")
+        tableModel.setEditStrategy(QSqlTableModel.OnFieldChange)
+        tableModel.select()
+        headers = ("ID", "Name", "Job", "Email")
+        for columnIndex, header in enumerate(headers):
+            tableModel.setHeaderData(columnIndex, Qt.Horizontal, header)
+        return tableModel
+
+    def addContact(self, data):
+        """Add a contact to the database."""
+        rows = self.model.rowCount()
+        self.model.insertRows(rows, 1)
+        for column_index, field in enumerate(data):
+            self.model.setData(self.model.index(rows, column_index + 1), field)
+        self.model.submitAll()
+        self.model.select()

python-contact-book/source_code_step_5/rpcontacts/views.py

+# -*- coding: utf-8 -*-
+
+"""This module provides views to manage the contacts table."""
+
+from PyQt5.QtCore import Qt
+from PyQt5.QtWidgets import (
+    QAbstractItemView,
+    QDialog,
+    QDialogButtonBox,
+    QFormLayout,
+    QHBoxLayout,
+    QLineEdit,
+    QMainWindow,
+    QMessageBox,
+    QPushButton,
+    QTableView,
+    QVBoxLayout,
+    QWidget,
+)
+
+from .model import ContactsModel
+
+
+class Window(QMainWindow):
+    """Main Window."""
+
+    def __init__(self, parent=None):
+        """Initializer."""
+        super().__init__(parent)
+        self.setWindowTitle("RP Contacts")
+        self.resize(550, 250)
+        self.centralWidget = QWidget()
+        self.setCentralWidget(self.centralWidget)
+        self.layout = QHBoxLayout()
+        self.centralWidget.setLayout(self.layout)
+
+        self.contactsModel = ContactsModel()
+        self.setupUI()
+
+    def setupUI(self):
+        """Setup the main window's GUI."""
+        # Create the table view widget
+        self.table = QTableView()
+        self.table.setModel(self.contactsModel.model)
+        self.table.setSelectionBehavior(QAbstractItemView.SelectRows)
+        self.table.resizeColumnsToContents()
+        # Create buttons
+        self.addButton = QPushButton("Add...")
+        self.addButton.clicked.connect(self.openAddDialog)
+        self.deleteButton = QPushButton("Delete")
+        self.clearAllButton = QPushButton("Clear All")
+        # Lay out the GUI
+        layout = QVBoxLayout()
+        layout.addWidget(self.addButton)
+        layout.addWidget(self.deleteButton)
+        layout.addStretch()
+        layout.addWidget(self.clearAllButton)
+        self.layout.addWidget(self.table)
+        self.layout.addLayout(layout)
+
+    def openAddDialog(self):
+        """Open the Add Contact dialog."""
+        dialog = AddDialog(self)
+        if dialog.exec() == QDialog.Accepted:
+            self.contactsModel.addContact(dialog.data)
+            self.table.resizeColumnsToContents()
+
+
+class AddDialog(QDialog):
+    """Add Contact dialog."""
+
+    def __init__(self, parent=None):
+        """Initializer."""
+        super().__init__(parent=parent)
+        self.setWindowTitle("Add Contact")
+        self.layout = QVBoxLayout()
+        self.setLayout(self.layout)
+        self.data = None
+
+        self.setupUI()
+
+    def setupUI(self):
+        """Setup the Add Contact dialog's GUI."""
+        # Create line edits for data fields
+        self.nameField = QLineEdit()
+        self.nameField.setObjectName("Name")
+        self.jobField = QLineEdit()
+        self.jobField.setObjectName("Job")
+        self.emailField = QLineEdit()
+        self.emailField.setObjectName("Email")
+        # Lay out the data fields
+        layout = QFormLayout()
+        layout.addRow("Name:", self.nameField)
+        layout.addRow("Job:", self.jobField)
+        layout.addRow("Email:", self.emailField)
+        self.layout.addLayout(layout)
+        # Add standard buttons to the dialog and connect them
+        self.buttonsBox = QDialogButtonBox(self)
+        self.buttonsBox.setOrientation(Qt.Horizontal)
+        self.buttonsBox.setStandardButtons(
+            QDialogButtonBox.Ok | QDialogButtonBox.Cancel
+        )
+        self.buttonsBox.accepted.connect(self.accept)
+        self.buttonsBox.rejected.connect(self.reject)
+        self.layout.addWidget(self.buttonsBox)
+
+    def accept(self):
+        """Accept the data provided through the dialog."""
+        self.data = []
+        for field in (self.nameField, self.jobField, self.emailField):
+            if not field.text():
+                QMessageBox.critical(
+                    self,
+                    "Error!",
+                    f"You must provide a contact's {field.objectName()}",
+                )
+                self.data = None  # Reset .data
+                return
+
+            self.data.append(field.text())
+
+        if not self.data:
+            return
+
+        super().accept()

python-contact-book/source_code_step_6/rpcontacts.py

+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+
+"""This module provides RP Contacts entry point script."""
+
+from rpcontacts.main import main
+
+if __name__ == "__main__":
+    main()

python-contact-book/source_code_step_6/rpcontacts/__init__.py

+# -*- coding: utf-8 -*-
+
+"""This module provides the rpcontacts package."""
+
+__version__ = "0.1.0"

python-contact-book/source_code_step_6/rpcontacts/database.py

+# -*- coding: utf-8 -*-
+
+"""This module provides a database connection."""
+
+from PyQt5.QtWidgets import QMessageBox
+from PyQt5.QtSql import QSqlDatabase, QSqlQuery
+
+
+def _createContactsTable():
+    """Create the contacts table in the database."""
+    createTableQuery = QSqlQuery()
+    return createTableQuery.exec(
+        """
+        CREATE TABLE IF NOT EXISTS contacts (
+            id INTEGER PRIMARY KEY AUTOINCREMENT UNIQUE NOT NULL,
+            name VARCHAR(40) NOT NULL,
+            job VARCHAR(50),
+            email VARCHAR(40) NOT NULL
+        )
+        """
+    )
+
+
+def createConnection(databaseName):
+    """Create and open a database connection."""
+    connection = QSqlDatabase.addDatabase("QSQLITE")
+    connection.setDatabaseName(databaseName)
+
+    if not connection.open():
+        QMessageBox.warning(
+            None,
+            "RP Contact",
+            f"Database Error: {connection.lastError().text()}",
+        )
+        return False
+
+    _createContactsTable()
+    return True

python-contact-book/source_code_step_6/rpcontacts/main.py

+# -*- coding: utf-8 -*-
+
+"""This module provides RP Contacts application."""
+
+import sys
+
+from PyQt5.QtWidgets import QApplication
+
+from .database import createConnection
+from .views import Window
+
+
+def main():
+    """RP Contacts main function."""
+    # Create the application
+    app = QApplication(sys.argv)
+    # Connect to the database before creating any window
+    if not createConnection("contacts.sqlite"):
+        sys.exit(1)
+    # Create the main window if the connection succeeded
+    win = Window()
+    win.show()
+    # Run the event loop
+    sys.exit(app.exec_())

python-contact-book/source_code_step_6/rpcontacts/model.py

+# -*- coding: utf-8 -*-
+
+"""This module provides a model to manage the contacts table."""
+
+from PyQt5.QtCore import Qt
+from PyQt5.QtSql import QSqlTableModel
+
+
+class ContactsModel:
+    def __init__(self):
+        self.model = self._createModel()
+
+    @staticmethod
+    def _createModel():
+        """Create and set up the model."""
+        tableModel = QSqlTableModel()
+        tableModel.setTable("contacts")
+        tableModel.setEditStrategy(QSqlTableModel.OnFieldChange)
+        tableModel.select()
+        headers = ("ID", "Name", "Job", "Email")
+        for columnIndex, header in enumerate(headers):
+            tableModel.setHeaderData(columnIndex, Qt.Horizontal, header)
+        return tableModel
+
+    def addContact(self, data):
+        """Add a contact to the database."""
+        rows = self.model.rowCount()
+        self.model.insertRows(rows, 1)
+        for column_index, field in enumerate(data):
+            self.model.setData(self.model.index(rows, column_index + 1), field)
+        self.model.submitAll()
+        self.model.select()
+
+    def deleteContact(self, row):
+        """Remove a contact from the database."""
+        self.model.removeRow(row)
+        self.model.submitAll()
+        self.model.select()
+
+    def clearContacts(self):
+        """Remove all contacts in the database."""
+        self.model.setEditStrategy(QSqlTableModel.OnManualSubmit)
+        self.model.removeRows(0, self.model.rowCount())
+        self.model.submitAll()
+        self.model.setEditStrategy(QSqlTableModel.OnFieldChange)
+        self.model.select()

python-contact-book/source_code_step_6/rpcontacts/views.py

+# -*- coding: utf-8 -*-
+
+"""This module provides views to manage the contacts table."""
+
+from PyQt5.QtCore import Qt
+from PyQt5.QtWidgets import (
+    QAbstractItemView,
+    QDialog,
+    QDialogButtonBox,
+    QFormLayout,
+    QHBoxLayout,
+    QLineEdit,
+    QMainWindow,
+    QMessageBox,
+    QPushButton,
+    QTableView,
+    QVBoxLayout,
+    QWidget,
+)
+
+from .model import ContactsModel
+
+
+class Window(QMainWindow):
+    """Main Window."""
+
+    def __init__(self, parent=None):
+        """Initializer."""
+        super().__init__(parent)
+        self.setWindowTitle("RP Contacts")
+        self.resize(550, 250)
+        self.centralWidget = QWidget()
+        self.setCentralWidget(self.centralWidget)
+        self.layout = QHBoxLayout()
+        self.centralWidget.setLayout(self.layout)
+
+        self.contactsModel = ContactsModel()
+        self.setupUI()
+
+    def setupUI(self):
+        """Setup the main window's GUI."""
+        # Create the table view widget
+        self.table = QTableView()
+        self.table.setModel(self.contactsModel.model)
+        self.table.setSelectionBehavior(QAbstractItemView.SelectRows)
+        self.table.resizeColumnsToContents()
+        # Create buttons
+        self.addButton = QPushButton("Add...")
+        self.addButton.clicked.connect(self.openAddDialog)
+        self.deleteButton = QPushButton("Delete")
+        self.deleteButton.clicked.connect(self.deleteContact)
+        self.clearAllButton = QPushButton("Clear All")
+        self.clearAllButton.clicked.connect(self.clearContacts)
+        # Lay out the GUI
+        layout = QVBoxLayout()
+        layout.addWidget(self.addButton)
+        layout.addWidget(self.deleteButton)
+        layout.addStretch()
+        layout.addWidget(self.clearAllButton)
+        self.layout.addWidget(self.table)
+        self.layout.addLayout(layout)
+
+    def openAddDialog(self):
+        """Open the Add Contact dialog."""
+        dialog = AddDialog(self)
+        if dialog.exec() == QDialog.Accepted:
+            self.contactsModel.addContact(dialog.data)
+            self.table.resizeColumnsToContents()
+
+    def deleteContact(self):
+        """Delete the selected contact from the database."""
+        row = self.table.currentIndex().row()
+        if row < 0:
+            return
+
+        messageBox = QMessageBox.warning(
+            self,
+            "Warning!",
+            "Do you want to remove the selected contact?",
+            QMessageBox.Ok | QMessageBox.Cancel,
+        )
+
+        if messageBox == QMessageBox.Ok:
+            self.contactsModel.deleteContact(row)
+
+    def clearContacts(self):
+        """Remove all contacts from the database."""
+        messageBox = QMessageBox.warning(
+            self,
+            "Warning!",
+            "Do you want to remove all your contacts?",
+            QMessageBox.Ok | QMessageBox.Cancel,
+        )
+
+        if messageBox == QMessageBox.Ok:
+            self.contactsModel.clearContacts()
+
+
+class AddDialog(QDialog):
+    """Add Contact dialog."""
+
+    def __init__(self, parent=None):
+        """Initializer."""
+        super().__init__(parent=parent)
+        self.setWindowTitle("Add Contact")
+        self.layout = QVBoxLayout()
+        self.setLayout(self.layout)
+        self.data = None
+
+        self.setupUI()
+
+    def setupUI(self):
+        """Setup the Add Contact dialog's GUI."""
+        # Create line edits for data fields
+        self.nameField = QLineEdit()
+        self.nameField.setObjectName("Name")
+        self.jobField = QLineEdit()
+        self.jobField.setObjectName("Job")
+        self.emailField = QLineEdit()
+        self.emailField.setObjectName("Email")
+        # Lay out the data fields
+        layout = QFormLayout()
+        layout.addRow("Name:", self.nameField)
+        layout.addRow("Job:", self.jobField)
+        layout.addRow("Email:", self.emailField)
+        self.layout.addLayout(layout)
+        # Add standard buttons to the dialog and connect them
+        self.buttonsBox = QDialogButtonBox(self)
+        self.buttonsBox.setOrientation(Qt.Horizontal)
+        self.buttonsBox.setStandardButtons(
+            QDialogButtonBox.Ok | QDialogButtonBox.Cancel
+        )
+        self.buttonsBox.accepted.connect(self.accept)
+        self.buttonsBox.rejected.connect(self.reject)
+        self.layout.addWidget(self.buttonsBox)
+
+    def accept(self):
+        """Accept the data provided through the dialog."""
+        self.data = []
+        for field in (self.nameField, self.jobField, self.emailField):
+            if not field.text():
+                QMessageBox.critical(
+                    self,
+                    "Error!",
+                    f"You must provide a contact's {field.objectName()}",
+                )
+                self.data = None  # Reset .data
+                return
+
+            self.data.append(field.text())
+
+        if not self.data:
+            return
+
+        super().accept()