import requests

from bs4 import BeautifulSoup

import time

def write_in_file(number,string):#output function

    with open ('D:\\python\\python_code\\hdoj\\'+str(number)+".txt","a+",encoding='utf-8') as f:

        f.write(string)

        f.close()

link = "http://acm.hdu.edu.cn/showproblem.php?pid="

headers = {

    'user-agent': 'Mozilla/5.0 (iPhone; CPU iPhone OS 11_0 like Mac OS X) AppleWebKit/604.1.38 (KHTML, like Gecko) Version/11.0 Mobile/15A372 Safari/604.1'

}

for i in range (1503,1900):

    print("acquire the request now")

    r = requests.get(link+str(i),headers = headers,timeout = 10)

    print("acquire the reuest completed")

    soup = BeautifulSoup(r.text,"lxml")

    problem_title = soup.find("h1").text#get the title

    write_in_file(i,"question: "+problem_title+"\n")

    problem_des = soup.find_all("div",class_="panel_content")

    the_title = soup.find_all("div",class_ ="panel_title")

    #print(the_title)

    print("write into file now")

    print("now write in the NO. "+str(i) +" file")

    len_of_the_title = len(the_title)

    for m in range(0,len_of_the_title):

        write_in_file(i,the_title[m].text+": "+problem_des[m].text+"\n")

    time.sleep(1)#sleep for one second