pip install PyQt5 PyQt5-tools

import PyQt5
print(PyQt5.__version__)  # Should show version like 5.15.4

import sys
from PyQt5.QtWidgets import QApplication, QLabel, QWidget

# 1. Create the application object
app = QApplication(sys.argv)

# 2. Create main window
window = QWidget()
window.setWindowTitle("My First App")
window.setGeometry(100, 100, 400, 200)  # x, y, width, height

# 3. Add a label
label = QLabel("Hello PyQt5!", parent=window)
label.move(150, 80)  # x, y position

# 4. Show the window
window.show()

# 5. Run the application
sys.exit(app.exec_())

from PyQt5.QtWidgets import (
    QPushButton,  # Clickable button
    QLineEdit,    # Single-line text input
    QTextEdit,    # Multi-line text area
    QCheckBox,    # Toggle option
    QRadioButton, # Exclusive choice
    QComboBox,    # Dropdown menu
    QSlider       # Value selector
)

from PyQt5.QtWidgets import (
    QVBoxLayout,  # Vertical arrangement
    QHBoxLayout,  # Horizontal arrangement
    QGridLayout   # Grid arrangement
)

from PyQt5.QtWidgets import QTabWidget, QTextEdit, QWidget

class TabDemo(QWidget):
    def __init__(self):
        super().__init__()
        
        tabs = QTabWidget()
        
        # Tab 1: Text Editor
        tab1 = QWidget()
        text_edit = QTextEdit()
        tab1_layout = QVBoxLayout()
        tab1_layout.addWidget(text_edit)
        tab1.setLayout(tab1_layout)
        
        # Tab 2: Settings
        tab2 = QWidget()
        tab2_layout = QVBoxLayout()
        tab2_layout.addWidget(QLabel("Settings Panel"))
        tab2.setLayout(tab2_layout)
        
        tabs.addTab(tab1, "Editor")
        tabs.addTab(tab2, "Settings")
        
        main_layout = QVBoxLayout()
        main_layout.addWidget(tabs)
        self.setLayout(main_layout)

def setup_file_tree(self):
    tree = QTreeWidget()
    tree.setHeaderLabels(["Name", "Size", "Type"])
    
    # Add parent items
    root = QTreeWidgetItem(tree)
    root.setText(0, "Project Root")
    
    # Add children
    for file in ["main.py", "config.ini", "README.md"]:
        child = QTreeWidgetItem(root)
        child.setText(0, file)
        child.setText(1, "10 KB")
        child.setText(2, "Python" if file.endswith(".py") else "Text")
    
    tree.expandAll()
    return tree

def setup_data_table(self):
    table = QTableWidget(5, 3)  # Rows, columns
    table.setHorizontalHeaderLabels(["ID", "Name", "Status"])
    
    sample_data = [
        [101, "Product A", "Active"],
        [102, "Product B", "Inactive"],
        [103, "Product C", "Pending"]
    ]
    
    for row, data in enumerate(sample_data):
        for col, text in enumerate(data):
            item = QTableWidgetItem(str(text))
            table.setItem(row, col, item)
    
    table.resizeColumnsToContents()
    return table

from PyQt5.QtCore import pyqtSignal, QObject

class Worker(QObject):
    progress_changed = pyqtSignal(int)
    task_completed = pyqtSignal(str)
    
    def run_task(self):
        for i in range(1, 101):
            time.sleep(0.05)
            self.progress_changed.emit(i)
        self.task_completed.emit("Task finished!")

# Multiple signals to single slot
button1.clicked.connect(self.handle_click)
button2.clicked.connect(self.handle_click)

# Signal with arguments
self.worker.progress_changed.connect(self.update_progress_bar)

# Lambda slots
button.clicked.connect(lambda: self.process_data(param1, param2))

# Slot decorator
@pyqtSlot()
def on_button_click(self):
    print("Button clicked!")

app.setStyleSheet("""
    QPushButton {
        background-color: #4CAF50;
        border: none;
        color: white;
        padding: 8px 16px;
        font-size: 14px;
    }
    QPushButton:hover {
        background-color: #45a049;
    }
    QLineEdit {
        padding: 5px;
        border: 1px solid #ccc;
        border-radius: 3px;
    }
""")

/* Style only buttons in the toolbar */
QToolBar QPushButton {
    min-width: 80px;
}

/* Style checked checkboxes differently */
QCheckBox:checked {
    color: #0085FF;
}

/* Style odd/even table rows */
QTableView::item:alternate {
    background: #f0f0f0;
}

# Change style programmatically
button.setStyleSheet("""
    QPushButton {
        background-color: red;
        font-weight: bold;
    }
""")

# Reset to default
button.setStyleSheet("")

class SettingsWindow(QDialog):
    def __init__(self):
        super().__init__()
        self.setWindowTitle("Settings")
        layout = QVBoxLayout()
        layout.addWidget(QLabel("Application Settings"))
        self.setLayout(layout)

# In main window:
def show_settings(self):
    settings = SettingsWindow()
    settings.exec_()  # Modal dialog
    # OR settings.show() for non-modal

# Main window with signal
class MainWindow(QMainWindow):
    settings_changed = pyqtSignal(dict)
    
    def open_settings(self):
        dialog = SettingsDialog(self)  # Pass parent
        if dialog.exec_():
            self.settings_changed.emit(dialog.get_settings())

# Settings dialog
class SettingsDialog(QDialog):
    def __init__(self, parent=None):
        super().__init__(parent)
        # ... setup UI ...
    
    def get_settings(self):
        return {"theme": self.theme_combo.currentText()}

model = QStringListModel()
model.setStringList(["Item 1", "Item 2", "Item 3"])

list_view = QListView()
list_view.setModel(model)

# Add items
model.insertRow(model.rowCount())
model.setData(model.index(model.rowCount()-1), "New Item")

class CustomTableModel(QAbstractTableModel):
    def __init__(self, data):
        super().__init__()
        self._data = data
    
    def rowCount(self, parent=None):
        return len(self._data)
    
    def columnCount(self, parent=None):
        return len(self._data[0]) if self._data else 0
    
    def data(self, index, role=Qt.DisplayRole):
        if role == Qt.DisplayRole:
            return str(self._data[index.row()][index.column()])
        return None

# Usage
data = [[1, "Alice"], [2, "Bob"], [3, "Charlie"]]
model = CustomTableModel(data)
table = QTableView()
table.setModel(model)

class TextEditor(QMainWindow):
    def __init__(self):
        super().__init__()
        self.setup_ui()
        self.setup_menu()
    
    def setup_ui(self):
        self.text_edit = QTextEdit()
        self.setCentralWidget(self.text_edit)
        
        # Status bar
        self.statusBar().showMessage("Ready")
        
        # Toolbar
        toolbar = self.addToolBar("Tools")
        save_act = QAction(QIcon("save.png"), "Save", self)
        save_act.triggered.connect(self.save_file)
        toolbar.addAction(save_act)
    
    def setup_menu(self):
        menubar = self.menuBar()
        
        # File menu
        file_menu = menubar.addMenu("File")
        
        open_act = QAction("Open", self)
        open_act.triggered.connect(self.open_file)
        file_menu.addAction(open_act)
        
        # Edit menu
        edit_menu = menubar.addMenu("Edit")
        edit_menu.addAction("Copy", self.text_edit.copy)
        edit_menu.addAction("Paste", self.text_edit.paste)
    
    def open_file(self):
        path, _ = QFileDialog.getOpenFileName()
        if path:
            with open(path, 'r') as f:
                self.text_edit.setText(f.read())
    
    def save_file(self):
        path, _ = QFileDialog.getSaveFileName()
        if path:
            with open(path, 'w') as f:
                f.write(self.text_edit.toPlainText())

from PyQt5.QtWidgets import (QFileDialog, QColorDialog, 
                            QFontDialog, QInputDialog, QMessageBox)

# File Dialog
file_path, _ = QFileDialog.getOpenFileName(
    self, "Open File", "", "Text Files (*.txt);;All Files (*)")

# Color Dialog
color = QColorDialog.getColor()

# Font Dialog
font, ok = QFontDialog.getFont()

# Input Dialog
text, ok = QInputDialog.getText(self, "Input", "Enter your name:")

# Message Box
reply = QMessageBox.question(
    self, "Message", "Are you sure?",
    QMessageBox.Yes | QMessageBox.No, QMessageBox.No)

class LoginDialog(QDialog):
    def __init__(self, parent=None):
        super().__init__(parent)
        self.setWindowTitle("Login")
        
        self.username = QLineEdit()
        self.password = QLineEdit()
        self.password.setEchoMode(QLineEdit.Password)
        
        buttons = QDialogButtonBox(
            QDialogButtonBox.Ok | QDialogButtonBox.Cancel)
        buttons.accepted.connect(self.accept)
        buttons.rejected.connect(self.reject)
        
        layout = QFormLayout()
        layout.addRow("Username:", self.username)
        layout.addRow("Password:", self.password)
        layout.addRow(buttons)
        
        self.setLayout(layout)
    
    def get_credentials(self):
        return (self.username.text(), self.password.text())

# Usage
dialog = LoginDialog()
if dialog.exec_():
    username, password = dialog.get_credentials()

from PyQt5.QtCore import QDir, QFile, QFileInfo

# Check file existence
file_info = QFileInfo("path/to/file")
if file_info.exists():
    print("File size:", file_info.size())

# Directory operations
directory = QDir()
directory.mkdir("new_folder")
print("Current path:", directory.currentPath())

# File reading/writing
file = QFile("data.txt")
if file.open(QIODevice.ReadOnly | QIODevice.Text):
    stream = QTextStream(file)
    content = stream.readAll()
    file.close()

from PyQt5.QtCore import QFileSystemWatcher

class FileMonitor(QObject):
    def __init__(self):
        super().__init__()
        self.watcher = QFileSystemWatcher()
        self.watcher.fileChanged.connect(self.on_file_changed)
    
    def add_file(self, path):
        self.watcher.addPath(path)
    
    def on_file_changed(self, path):
        print(f"File changed: {path}")

monitor = FileMonitor()
monitor.add_file("important_file.txt")

class DropArea(QLabel):
    def __init__(self):
        super().__init__("Drop files here")
        self.setAcceptDrops(True)
        self.setAlignment(Qt.AlignCenter)
        self.setStyleSheet("border: 2px dashed #aaa;")
    
    def dragEnterEvent(self, event):
        if event.mimeData().hasUrls():
            event.acceptProposedAction()
    
    def dropEvent(self, event):
        for url in event.mimeData().urls():
            file_path = url.toLocalFile()
            print("Dropped file:", file_path)

    def show_error(self, message):
        self.thread.quit()
        QMessageBox.critical(self, "Error", message)

class FileWorker(QObject):
    progress = pyqtSignal(int)
    finished = pyqtSignal()
    er