**Designing a Real-World File Explorer with PyQt6 and MVC Architecture** In this example, we will design a real-world file explorer application using PyQt6 and the Model-View-Controller (MVC) architecture. This example showcases how to structure complex applications with a clear separation of concerns. **Requirements** * PyQt6 * Python 3.8+ * Windows, macOS, or Linux **File Structure** * file_explorer/ + main.py + model/ - file_system_model.py * view/ - file_explorer_view.py * controller/ - file_explorer_controller.py + resources/ **Model** The `file_system_model.py` contains the `FileSystemModel` class, responsible for handling file system operations: ```python # file_system_model.py import os from PyQt6.QtCore import QAbstractItemModel, QModelIndex, Qt class FileSystemModel(QAbstractItemModel): def __init__(self, root_path): super().__init__() self._root_path = root_path self._file_system = {} def index(self, row, column, parent=QModelIndex()): if not self.hasIndex(row, column, parent): return QModelIndex() if not parent.isValid(): return self.createIndex(row, column, self._root_path) parent_dir = parent.internalId() files = self._file_system.get(parent_dir, []) if row >= len(files): return QModelIndex() return self.createIndex(row, column, files[row]) def parent(self, index): if not index.isValid(): return QModelIndex() parent_dir = os.path.dirname(index.internalId()) return self.createIndex(0, 0, parent_dir) def rowCount(self, parent=QModelIndex()): if not parent.isValid(): return 1 parent_dir = parent.internalId() files = self._file_system.get(parent_dir, []) return len(files) def data(self, index, role): if not index.isValid(): return None file_path = index.internalId() if role == Qt.ItemDataRole.DisplayRole: return os.path.basename(file_path) return None ``` **View** The `file_explorer_view.py` contains the `FileExplorerView` class, responsible for displaying the file system: ```python # file_explorer_view.py import sys from PyQt6.QtWidgets import QApplication, QTreeView from PyQt6.QtGui import QStandardItemModel from PyQt6.QtCore import Qt class FileExplorerView(QTreeView): def __init__(self, model): super().__init__() self.setModel(model) ``` **Controller** The `file_explorer_controller.py` contains the `FileExplorerController` class, responsible for handling user interactions: ```python # file_explorer_controller.py import sys from PyQt6.QtWidgets import QApplication from PyQt6.QtCore import Qt from model.file_system_model import FileSystemModel from view.file_explorer_view import FileExplorerView class FileExplorerController: def __init__(self): self.model = FileSystemModel(os.getcwd()) self.view = FileExplorerView(self.model) def run(self): app = QApplication(sys.argv) self.view.show() sys.exit(app.exec()) ``` **Running the Application** To run the application, execute the `main.py` file: ```python # main.py import sys from controller.file_explorer_controller import FileExplorerController def main(): controller = FileExplorerController() controller.run() if __name__ == "__main__": main() ``` **Output** The application will display a file explorer with the root directory set to the current working directory. **Best Practices and Productivity Hacks** * Use the MVC architecture to separate concerns and improve maintainability. * Use PyQt6's `QAbstractItemModel` to handle file system operations. * Use `QTreeView` to display the file system. * Use `QStandardItemModel` to handle file item data. * Use `Qt.ItemDataRole.DisplayRole` to display file names. **Search Engine-Friendly Titles** * "Designing a Real-World File Explorer with PyQt6 and MVC Architecture" * "PyQt6 File Explorer Tutorial" * "MVC Architecture in PyQt6"

# file_system_model.py
import os
from PyQt6.QtCore import QAbstractItemModel, QModelIndex, Qt

class FileSystemModel(QAbstractItemModel):
    def __init__(self, root_path):
        super().__init__()
        self._root_path = root_path
        self._file_system = {}

    def index(self, row, column, parent=QModelIndex()):
        if not self.hasIndex(row, column, parent):
            return QModelIndex()

        if not parent.isValid():
            return self.createIndex(row, column, self._root_path)

        parent_dir = parent.internalId()
        files = self._file_system.get(parent_dir, [])
        if row >= len(files):
            return QModelIndex()

        return self.createIndex(row, column, files[row])

    def parent(self, index):
        if not index.isValid():
            return QModelIndex()

        parent_dir = os.path.dirname(index.internalId())
        return self.createIndex(0, 0, parent_dir)

    def rowCount(self, parent=QModelIndex()):
        if not parent.isValid():
            return 1

        parent_dir = parent.internalId()
        files = self._file_system.get(parent_dir, [])
        return len(files)

    def data(self, index, role):
        if not index.isValid():
            return None

        file_path = index.internalId()
        if role == Qt.ItemDataRole.DisplayRole:
            return os.path.basename(file_path)

        return None

# file_explorer_view.py
import sys
from PyQt6.QtWidgets import QApplication, QTreeView
from PyQt6.QtGui import QStandardItemModel
from PyQt6.QtCore import Qt

class FileExplorerView(QTreeView):
    def __init__(self, model):
        super().__init__()
        self.setModel(model)

# file_explorer_controller.py
import sys
from PyQt6.QtWidgets import QApplication
from PyQt6.QtCore import Qt
from model.file_system_model import FileSystemModel
from view.file_explorer_view import FileExplorerView

class FileExplorerController:
    def __init__(self):
        self.model = FileSystemModel(os.getcwd())
        self.view = FileExplorerView(self.model)

    def run(self):
        app = QApplication(sys.argv)
        self.view.show()
        sys.exit(app.exec())

# main.py
import sys
from controller.file_explorer_controller import FileExplorerController

def main():
    controller = FileExplorerController()
    controller.run()

if __name__ == "__main__":
    main()