import requests
from bs4 import BeautifulSoup
#从BV号获取CID
def get_cid_from_bv(bv_ids):
    cids=[]
    for bv_id in bv_ids:
        # 视频详情 API 地址
        video_url = f'https://api.bilibili.com/x/web-interface/view?bvid={bv_id}'

        # 发送请求
        response = requests.get(video_url, headers=headers)
        response.raise_for_status()
        data = response.json()
        # 提取 cid
        if data.get('code') == 0:
            cid = data.get('data', {}).get('cid')
            cids.append(cid)
    return cids

def get_danmu(id):
    global videosnumber
    video_url = f'https://api.bilibili.com/x/v1/dm/list.so?oid={id}'
    response = requests.get(video_url, headers=headers) #要爬取的网址
    response.encoding='utf-8' #编码方式
    html = response.text
    soup = BeautifulSoup(html) #使用beautifulsoup库快速查找我们想要的信息
    all_txt = soup.findAll("d") #寻找到所有包含d的行
    txt=[all_txts.attrs ["p"]for all_txts in all_txt] #寻找到所有包含d的行中属性为p的值，这里边包含了弹幕的虚拟id等
    txtss=[all_txts.string for all_txts in all_txt] #寻找到所有包含d的行中的字符串数据，即弹幕内容
    txtsss=[txts.replace(' ','') for txts in txtss] #将字符串中的空格消除掉
    videosnumber = videosnumber  +1
    bulletnumber = len(txtsss)
    print( f"这是第{videosnumber}视频, 获取到{bulletnumber}弹幕")
    time.sleep(1)#休眠防被封
    return(txtsss) 

def main(kword,mubiao):
    bvs=[]
    alltxt=[]
    for i in range(100):
        cids = []
        cids = get_cid_from_bv(bvs)
        for id in cids:
            if(videosnumber>=mubiao): break
            txt = get_danmu(id)
            alltxt=alltxt + txt
        if(videosnumber>=mubiao): break
    return(alltxt)


flag = 50 #你要爬的视频数量
altxt=main(keword,flag)