import ijson


def extract_value(json_file_path, target_key):
    with open(json_file_path, 'r', encoding='utf-8') as file:
        # 使用 ijson.items 方法进行流式解析
        items = ijson.items(file, 'a')

        # 提取值
        for item in items:
            # 如果目标键存在于当前项中，返回相应的值
            if target_key in item:
                print(target_key)
                yield target_key


# 示例用法
json_file_path = 'test.json' # 里面包含  {"a": "a"}
target_key = 'a'

for value in extract_value(json_file_path, target_key):
    print(value)