mainPlugin.py

from qgis.PyQt.QtGui import *
from qgis.PyQt.QtWidgets import *

# initialize Qt resources from file resources.py
from . import resources

class TestPlugin:

  def __init__(self, iface):
    # save reference to the QGIS interface
    self.iface = iface

  def initGui(self):
    # create action that will start plugin configuration
    self.action = QAction(QIcon("testplug:icon.png"),
                          "Test plugin",
                          self.iface.mainWindow())
    self.action.setObjectName("testAction")
    self.action.setWhatsThis("Configuration for test plugin")
    self.action.setStatusTip("This is status tip")
    self.action.triggered.connect(self.run)

    # add toolbar button and menu item
    self.iface.addToolBarIcon(self.action)
    self.iface.addPluginToMenu("&Test plugins", self.action)

    # connect to signal renderComplete which is emitted when canvas
    # rendering is done
    self.iface.mapCanvas().renderComplete.connect(self.renderTest)

  def unload(self):
    # remove the plugin menu item and icon
    self.iface.removePluginMenu("&Test plugins", self.action)
    self.iface.removeToolBarIcon(self.action)

    # disconnect form signal of the canvas
    self.iface.mapCanvas().renderComplete.disconnect(self.renderTest)

  def run(self):
    # create and show a configuration dialog or something similar
    print("TestPlugin: run called!")

  def renderTest(self, painter):
    # use painter for drawing to map canvas
    print("TestPlugin: renderTest called!")

def initGui(self):
    self.menu = QMenu(self.iface.mainWindow())
    self.menu.setObjectName("testMenu")
    self.menu.setTitle("MyMenu")

    self.action = QAction(QIcon("testplug:icon.png"),
                          "Test plugin",
                          self.iface.mainWindow())
    self.action.setObjectName("testAction")
    self.action.setWhatsThis("Configuration for test plugin")
    self.action.setStatusTip("This is status tip")
    self.action.triggered.connect(self.run)
    self.menu.addAction(self.action)

    menuBar = self.iface.mainWindow().menuBar()
    menuBar.insertMenu(self.iface.firstRightStandardMenu().menuAction(),
                       self.menu)

def unload(self):
    self.menu.deleteLater()


def initGui(self):

    self.help_action = QAction(
        QIcon("testplug:icon.png"),
        self.tr("Test Plugin..."),
        self.iface.mainWindow()
    )
    # Add the action to the Help menu
    self.iface.pluginHelpMenu().addAction(self.help_action)

    self.help_action.triggered.connect(self.show_help)

@staticmethod
def show_help():
    """ Open the online help. """
    QDesktopServices.openUrl(QUrl('https://docs.qgis.org'))

def unload(self):

    self.iface.pluginHelpMenu().removeAction(self.help_action)
    del self.help_action