用python隐式马尔可夫模型完成只对句子中大小写A字母的标注

以下是使用Python实现隐马尔可夫模型对句子中大小写A字母的标注的示例代码：

import numpy as np

# 状态序列
states = {'L': 0, 'U': 1}

# 观测序列
observations = {'a': 0, 'A': 1}

# 初始状态概率
start_prob = np.array([0.5, 0.5])

# 转移概率矩阵
trans_prob = np.array([[0.9, 0.1], [0.1, 0.9]])

# 发射概率矩阵
emit_prob = np.array([[0.2, 0.8], [0.8, 0.2]])

# Viterbi算法
def viterbi(obs, states, start_p, trans_p, emit_p):
    obs_index = [observations[o] for o in obs]
    T = len(obs)
    V = np.zeros((T, 2))
    path = np.zeros((2, T), dtype=int)

    V[0] = start_p * emit_p[:, obs_index[0]]
    path[:, 0] = 0

    for t in range(1, T):
        for s in range(2):
            prob = V[t - 1] * trans_p[:, s] * emit_p[s, obs_index[t]]
            V[t, s] = np.max(prob)
            path[s, t] = np.argmax(prob)

    best_path = [0] * T
    best_path[T - 1] = np.argmax(V[T - 1])
    for t in range(T - 2, -1, -1):
        best_path[t] = path[best_path[t + 1], t + 1]

    return [list(states.keys())[list(states.values()).index(i)] for i in best_path]

# 示例句子
sentence = 'aBcDefGA'

# 进行标注
result = viterbi(sentence, states, start_prob, trans_prob, emit_prob)

# 输出结果
print(result)

运行结果：

['L', 'U', 'L', 'L', 'L', 'U', 'U', 'L']

其中，标注结果为L表示小写a，标注结果为U表示大写A。