爬虫下载rockchip的规格书

#file-name: pdf_download.py
import os
import requests
from bs4 import BeautifulSoup
def download_file(url, index):
    #local_filename1 = index+"-"+url.split('/')[-1]
    local_filename1 = url.split('/')[-1]
    local_filename = local_filename1.replace('%20','_')
    # NOTE the stream=True parameter
    r = requests.get(url, stream=True)
    with open(local_filename, 'wb') as f:
        for chunk in r.iter_content(chunk_size=1024):
            if chunk: # filter out keep-alive new chunks
                f.write(chunk)
                f.flush()
    return local_filename

root_link="https://rockchip.fr/"
#sub = ["main1", "ampak", "chipspark", "firefly", "geekbox", "marsboard", "radxa", "RK312X TRM", "RK3288 TRM"]
sub = [ "ampak", "chipspark", "firefly", "geekbox", "marsboard", "radxa", "RK312X TRM", "RK3288 TRM"]
for i in sub:
    if(i != "main"):
        r=requests.get(root_link+i)
        if(not os.path.exists(i)):
            directory = i.replace(" ", "_")
            os.mkdir( "./"+directory )
            os.chdir( "./"+directory)
        else:
            continue
    #//else:
    #    r=requests.get(root_link)

    print(root_link+i)
    if r.status_code==200:
        soup=BeautifulSoup(r.text)
        # print(soup.prettify())
        index=1
        for link in soup.find_all('a'):
            new_link=root_link+i+'/'+link.get('href')
            if new_link.endswith(".pdf") or new_link.endswith(".DSN") or new_link.endswith(".apk")  :
                file_path=download_file(new_link,str(index))
                print("downloading:"+new_link+" -> "+file_path)
                index+=1
        print(i+" download finished")
    else:
        print("errors occur.")
        exit()

    if(i != "main"):
        os.chdir( "../")
    #else:
    #   pass

print("all download finished")