如何统计嵌套字典中关键字出现的频率？

def count_keyword_frequency(data, keyword):
    count = 0
    if isinstance(data, dict):
        for key, value in data.items():
            if key == keyword:
                count += 1
            count += count_keyword_frequency(value, keyword)
    elif isinstance(data, list):
        for item in data:
            count += count_keyword_frequency(item, keyword)
    return count

data = {
    'key1': 'value1',
    'key2': {
        'key3': 'value2',
        'key4': {
            'key5': 'value3',
            'key6': 'value4'
        }
    },
    'key7': [
        {'key8': 'value5'},
        {'key9': 'value6'}
    ]
}

keyword = 'key6'
frequency = count_keyword_frequency(data, keyword)
print(f"The keyword '{keyword}' appears {frequency} times.")

The keyword 'key6' appears 1 times.