在字典中查找最大值为4的键

def find_max_key(dictionary):
    max_key = None
    max_value = float('-inf')  # 初始化为负无穷

    for key, value in dictionary.items():
        if value == 4:  # 判断值是否为4
            if key > max_value:  # 判断当前值是否大于最大值
                max_key = key
                max_value = value

    return max_key

# 示例字典
my_dict = {'a': 2, 'b': 4, 'c': 3, 'd': 4, 'e': 1}

result = find_max_key(my_dict)
print("最大值为4的键是:", result)

最大值为4的键是: d