TypeError: string indices must be integers

def load_data(self):
        reviews = pd.read_csv('tuniu.csv')  
        data = reviews['content']
        #with open('r.json') as file:
           #data = file.read()
        #data = json.loads(data)
        #print(type(data))
        return data

    def fenci_data(self):
            text = []
            data = self.load_data()
            with open("stoplist.txt", 'r',encoding='UTF-8') as file:
                stop_word_list = file.read()
            for weibo_item in tqdm(data):
                tmp = []
                sentence=''.join(re.findall(r'[\u4e00-\u9fa5]+',weibo_item['content']))
                for word in jieba.lcut(sentence):
                    if word not in stop_word_list:
                        tmp.append(word)
                text.append(tmp)
            return text

报错：
sentence=''.join(re.findall(r'[\u4e00-\u9fa5]+',weibo_item['content']))
TypeError: string indices must be integers

那就是只传 content 这一列而已。

sentence=''.join(re.findall(r'[\u4e00-\u9fa5]+',weibo_item['content']))

# 改为

sentence=''.join(re.findall(r'[\u4e00-\u9fa5]+',weibo_item))

看提示， 这个 weibo_item 的当前的值 是 字符串， 不是字典。
试试把
sentence=''.join(re.findall(r'[\u4e00-\u9fa5]+',weibo_item['content']))
改为

try:
    sentence=''.join(re.findall(r'[\u4e00-\u9fa5]+',weibo_item['content']))
except Exception as e :
    print("error",repr(e),'\n',weibo_item)
    sentence = ""

你看提示
weibo_item 是字符串， 咋取 weibo_item['content'] ?

先把两个文件都截图贴一下，描述下你的程序逻辑。