Python中如何定义可扩展的插件类？

class TextProcessor:
    def process(self, text):
        raise NotImplementedError("Subclass must implement abstract method")

class WordCounter(TextProcessor):
    def process(self, text):
        words = text.split()
        return len(words)

class SentimentAnalyzer(TextProcessor):
    def process(self, text):
        # 这里可以实现一个简单的情感分析逻辑
        positive_words = ['good', 'great', 'excellent']
        negative_words = ['bad', 'terrible', 'awful']
        score = sum(1 for word in text.lower().split() if word in positive_words) - \
                sum(1 for word in text.lower().split() if word in negative_words)
        return score

# 使用插件
plugins = [WordCounter(), SentimentAnalyzer()]
text = "This is a good day but the weather is terrible."

for plugin in plugins:
    result = plugin.process(text)
    print(f"{plugin.__class__.__name__} result: {result}")

import importlib

class PluginManager:
    def __init__(self):
        self.plugins = {}

    def register_plugin(self, name, plugin_class):
        self.plugins[name] = plugin_class()

    def load_plugin(self, module_name, class_name):
        module = importlib.import_module(module_name)
        plugin_class = getattr(module, class_name)
        self.register_plugin(class_name, plugin_class)

    def process(self, text):
        results = {}
        for name, plugin in self.plugins.items():
            results[name] = plugin.process(text)
        return results

# 假设我们有两个插件文件：word_counter.py 和 sentiment_analyzer.py
manager = PluginManager()
manager.load_plugin('word_counter', 'WordCounter')
manager.load_plugin('sentiment_analyzer', 'SentimentAnalyzer')

text = "This is a good day but the weather is terrible."
results = manager.process(text)
for name, result in results.items():
    print(f"{name} result: {result}")