如何使用用户输入从嵌套字典中提取值

def extract_value_from_nested_dict(nested_dict, keys):
    current_dict = nested_dict
    for key in keys:
        if isinstance(current_dict, dict) and key in current_dict:
            current_dict = current_dict[key]
        else:
            return None
    return current_dict

nested_dict = {
    'key1': {
        'key2': {
            'key3': 'value'
        }
    }
}

keys = ['key1', 'key2', 'key3']
value = extract_value_from_nested_dict(nested_dict, keys)
print(value)  # 输出: 'value'