如何在Python中使用快速多模式匹配算法

class ACNode:
    def __init__(self, value=None):
        self.value = value
        self.fail = None
        self.goto = {}

class AC:
    def __init__(self):
        self.__root = ACNode()
        self.__match = {}

    def add(self, pattern):
        node = self.__root
        for char in pattern:
            node = node.goto.setdefault(char, ACNode(char))
        if node.value is None:
            node.value = pattern
        self.__match.setdefault(node.value, set())
        self.__match[node.value].add(len(pattern))

    def build_fail(self):
        queue = [self.__root]
        while queue:
            node = queue.pop(0)
            for char, child in node.goto.items():
                queue.append(child)
                fail = node.fail
                while fail and char not in fail.goto:
                    fail = fail.fail
                child.fail = fail.goto[char] if fail else self.__root
                child_match = set(self.__match.get(child.value, []))
                child_match.update(self.__match.get(child.fail.value, []))
                self.__match[child.value] = child_match

    def search(self, text):
        result = {}
        node = self.__root
        for i, char in enumerate(text):
            while node and char not in node.goto:
                node = node.fail
            if node is None:
                node = self.__root
                continue
            node = node.goto[char]
            for word, positions in self.__match.items():
                for position in positions:
                    if i-position+1 >= 0 and text[i-position+1:i+1] == word:
                        result.setdefault(word, [])
                        result[word].append(i-position+1)
        return result

ac = AC()
ac.add('pidancode.com')
ac.add('皮蛋编程')
ac.build_fail()
text = 'pidancode.com是一个很棒的编程网站，我们可以在pidancode.com上学到很多知识。另外，pidancode.com还有很多优秀的编程工具和技术文章，值得一看。'
print(ac.search(text))

{'pidancode.com': [0, 41], '皮蛋编程': [13]}