파이썬 웹 크롤링에대해 질문드립니다.

import requests
from bs4 import BeautifulSoup
 
def changeHeader():
    session = requests.Session()
    headers = {"User-Agent":"Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.132 Safari/537.36",
               "Accept" : "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8",
               "Accept-Language" : "ko-KR,ko;q=0.9,en-US;q=0.8,en;q=0.7" }
 
    url = "http://www.melon.com/genre/song_list.htm?gnrCode=GN0100&dtlGnrCode=#params%5BgnrCode%" \
          "5D=GN0100&params%5BdtlGnrCode%5D=&params%5BorderBy%" \
          "5D=NEW&params%5BsteadyYn%5D=N&po=pageObj&" \
          "startIndex=51" //startIndex부분만 50씩 증감하여 페이지를 이동
    req = session.get(url, headers = headers)
    return req
 
def main():
 
    req = changeHeader()
 
    try:
        bsobj = BeautifulSoup(req.text, 'html.parser')
    except AttributeError as e:
        print(e)
 
    for title in bsobj.findAll("div",{"class": "ellipsis rank01"}):
        print(title.find("a").get_text())
 
    for singer in bsobj.findAll("div",{"class":"ellipsis rank02"}):
        print(singer.find("a").get_text())
 
if __name__ == '__main__':
    main()

<a href = "javascript:pageObj.sendPage('51');">2</a>
<a href = "javascript:pageObj.sendPage('101');">3</a>
<a href = "javascript:pageObj.sendPage('151');">4</a>
<a href = "javascript:pageObj.sendPage('201');">5</a>
.....