The application implements four core functions:

1. Create credential records (service name, username, password, URL)
2. Modify existing entreis
3. Delete records
4. Backup data via email export

Datta persistence uses SQLite database storage.

Implementation

import sys
from PyQt5.QtWidgets import (
    QApplication, QMainWindow, QTableWidget, QAbstractItemView,
    QAction, QToolBar
)
from PyQt5.QtGui import QIcon
from PyQt5.QtCore import Qt

class CredentialVault(QMainWindow):
    def __init__(self):
        super().__init__()
        self.setup_toolbar()
        self.initialize_database()
        self.configure_table_view()
        self.setGeometry(300, 300, 650, 300)
        self.setWindowTitle('Credential Vault')
        self.setWindowIcon(QIcon(':/icons/app_icon.png'))

    def setup_toolbar(self):
        # Action definitions
        create_act = QAction(QIcon(':/icons/add.png'), 'Add Entry (Ctrl+N)', self)
        edit_act = QAction(QIcon(':/icons/edit.png'), 'Edit Entry (Ctrl+E)', self)
        delete_act = QAction(QIcon(':/icons/delete.png'), 'Remove Entry', self)
        export_act = QAction(QIcon(':/icons/export.png'), 'Export Data (Ctrl+B)', self)
        
        # Keyboard shortcuts
        create_act.setShortcut('Ctrl+N')
        edit_act.setShortcut('Ctrl+E')
        delete_act.setShortcut('Del')
        export_act.setShortcut('Ctrl+B')
        
        # Event connections
        create_act.triggered.connect(self.add_record)
        edit_act.triggered.connect(self.modify_record)
        delete_act.triggered.connect(self.remove_record)
        export_act.triggered.connect(self.export_data)
        
        # Toolbar organization
        tb_add = self.addToolBar('Create')
        tb_edit = self.addToolBar('Modify')
        tb_remove = self.addToolBar('Delete')
        tb_export = self.addToolBar('Backup')
        
        tb_add.addAction(create_act)
        tb_edit.addAction(edit_act)
        tb_remove.addAction(delete_act)
        tb_export.addAction(export_act)

    def initialize_database(self):
        pass  # Database connection stub

    def configure_table_view(self):
        self.data_table = QTableWidget()
        self.setCentralWidget(self.data_table)
        self.data_table.setColumnCount(4)
        self.data_table.setRowCount(0)
        col_widths = [100, 150, 200, 200]
        
        for col_idx, width in enumerate(col_widths):
            self.data_table.setColumnWidth(col_idx, width)
            
        headers = ['Service', 'Username', 'Password', 'URL']
        self.data_table.setHorizontalHeaderLabels(headers)
        self.data_table.setEditTriggers(QAbstractItemView.NoEditTriggers)
        self.data_table.setSelectionBehavior(QAbstractItemView.SelectRows)

    # Handler stubs
    def add_record(self): pass
    def modify_record(self): pass
    def remove_record(self): pass
    def export_data(self): pass

if __name__ == '__main__':
    application = QApplication(sys.argv)
    vault_window = CredentialVault()
    vault_window.show()
    sys.exit(application.exec_())

Key components:

• Toolbar Setup: Creates icon-based actions with keyboard shortcuts
• Database Initialization: Placeholder for SQLite integration
• Table Configuration: Non-editable grid with column sizing and header labels
• Event Handlesr: Stubs for CRUD operations and data export