Python 简单的方法爬取b站dnf视频封面

import urllib.request
cnt=0
def instr(keystr):
    st=keystr.find('(')+1
    strhtml=keystr[st:len(keystr)-1]
    return strhtml

def picsave(strJson,number):
    global cnt
    strdic=strJson['data']['archives']
    num=len(strdic)
    for i in range(0,num,1):
        cnt=cnt+1
        strdic=strJson['data']['archives'][i]
        print(strdic['pic'])
        urllib.request.urlretrieve(strdic['pic'],'E:图片dnf\%s.jpg'%(cnt))

def urlget(num):
    for i in range(1,num,1):
        url='https://api.bilibili.com/x/tag/ranking/archives?callback=jQuery172014070206081723846_1514982701564&tag_id=5033&rid=65&type=0&pn='+str(i)+'&ps=20&jsonp=jsonp&_=1514982702144'
        response=urllib.request.urlopen(url)
        html=response.read().decode('utf-8')
        html=instr(html)
        strJson=eval(html)
        picsave(strJson,i)

urlget(6)
print("ok")