如何使用Python实现马尔可夫链算法？

import randomdef generate_transition_matrix(text):    # 将文本拆分为单词    words = text.split()        # 统计相邻单词的频次    transition_matrix = {}    for i in range(len(words)-1):        current_word = words[i]        next_word = words[i+1]        if current_word not in transition_matrix:            transition_matrix[current_word] = {}        if next_word not in transition_matrix[current_word]:            transition_matrix[current_word][next_word] = 0        transition_matrix[current_word][next_word] += 1        # 将频次转换为概率    for current_word in transition_matrix:        total_count = sum(transition_matrix[current_word].values())        for next_word in transition_matrix[current_word]:            transition_matrix[current_word][next_word] /= total_count        return transition_matrixdef generate_text(transition_matrix, start_word, num_words):    current_word = start_word    text = [current_word]        for _ in range(num_words-1):        if current_word not in transition_matrix:            break        next_word = random.choices(list(transition_matrix[current_word].keys()),                                   list(transition_matrix[current_word].values()))[0]        text.append(next_word)        current_word = next_word        return ' '.join(text)# 示例文本text = "我爱中国，中国人民是伟大的！"start_word = "我"num_words = 10# 生成状态转移矩阵transition_matrix = generate_transition_matrix(text)# 生成新的文本generated_text = generate_text(transition_matrix, start_word, num_words)print(generated_text)