关键字爬google的pdf

import google
import requests
def download_file(url,index):
    local_filename=index+"-"+url.split("/")[-1]
    r=requests.get(url,stream=True)
    with open(local_filename,"wb") as f:
        for chunk in r.iter_content(chunk_size=1024):
            if chunk:
                f.write(chunk)
                f.flush
    return local_filename            
g=google.search('site:*.gov.ph filetype:pdf',tld='com.hk')
index=1
for url in g:
    if url.endswith(".pdf"):
        file_path=download_file(url,str(index))
        print "downloading:"+url+"->"+file_path
        index+=1
print "all download finished"