A Simple Plugin System by Python

Due to the requirements of my work, I needed to design an open software system, and immediately thought of the Python language. As a result, I designed a simple and easily extensible plugin system.

Here’s the code:

#main.py


import importlib

class PluginManager:
    def __init__(self):
        self.plugins = []
        self.func_name = "MyPlugin"

    def load_plugin(self, plugin_name):
        try:
            plugin_module = importlib.import_module(f'plugins.{plugin_name}')
            plugin_instance = getattr(plugin_module, self.func_name)()
            self.plugins.append(plugin_instance)
            print(f"plugin {plugin_name} loaded.")
        except ImportError:
            print(f"Load plugin {plugin_name} failed.")

    def run_plugins(self):
        for plugin in self.plugins:
            plugin.run()


if __name__ == "__main__":
    manager = PluginManager()

    while True:
        print("1. Add Plugin")
        print("2. Run Plugin")
        print("3. Quit")
        choice = input("Your Select: ")

        if choice == "1":
            plugin_name = input("Please input the name of plugin: ")
            manager.load_plugin(plugin_name)

        elif choice == "2":
            manager.run_plugins()

        elif choice == "3":
            break

Then, you create a directory named ‘plugins.’ In this directory, you can add your plugin, which must define a class named ‘MyPlugin’ and must have a function named ‘run’. Here is the simple code:

#my_plugin

class MyPlugin:
    def __init__(self):
        pass
    def run(self):
        print("MyPlugin is running")

The following is the running process:

1. Add Plugin
2. Run Plugin
3. Quit
Your Select: 1
Please input the name of plugin: my_plugin
plugin my_plugin loaded.
1. Add Plugin
2. Run Plugin
3. Quit
Your Select: 2
MyPlugin is running
1. Add Plugin
2. Run Plugin
3. Quit
Your Select: 3
PS C:\Users\xxx\Desktop\yyy\plugin-system>

You can use this model to design a big and an opened software system.