我怎样才能找到我的列表中关键字最多的字典？

def find_dict_with_most_keywords(lst):
    keyword_count = {}
    max_count = 0
    max_keyword = None

    for item in lst:
        if isinstance(item, dict):
            for keyword in item.keys():
                if keyword in keyword_count:
                    keyword_count[keyword] += 1
                else:
                    keyword_count[keyword] = 1

                if keyword_count[keyword] > max_count:
                    max_count = keyword_count[keyword]
                    max_keyword = keyword

    return max_keyword

# 示例用法
my_list = [{'key1': 'value1'}, {'key2': 'value2'}, {'key1': 'value3'}, {'key3': 'value4'}]
result = find_dict_with_most_keywords(my_list)
print(result)  # 输出 'key1'