python+xpath+requests爬取维基百科历史上的今天

import requests
import urllib.parse
import datetime
from lxml import etree

fhout = open("result.txt", 'a')

baseurl = 'https://zh.wikipedia.org/wiki/'

begin_date = datetime.datetime.strptime('2016-01-01', "%Y-%m-%d")
contents=[]
for i in range(196,366):
    content = []
    mid_date = begin_date + datetime.timedelta(days=i)
    thedate = str(mid_date.month) + '月' + str(mid_date.day) + '日'
    print(thedate)
    urlthedate = urllib.parse.quote(thedate)
    url = baseurl + urlthedate
    print(url)
    html = requests.get(url).text.encode("utf-8")

    tree = etree.HTML(html)
    ul = tree.xpath('//li[@class="toclevel-1 tocsection-1"]/ul/li/a/span[@class="toctext"]/text()')
    num = len(ul)
    fhout.write("data_"+str(mid_date.month)+"_"+str(mid_date.day)+"=[")
    for i in range(num, 0, -1):
        records = tree.xpath('//div[@id="mw-content-text"]/div[@class="mw-parser-output"]/ul['+ str(i) +']/li[descendant-or-self::text()]')
        ulen = len(records)
        for j in range(ulen-1,-1,-1):
            content.append(records[j].xpath('string(.)'))
            fhout.write("'"+records[j].xpath('string(.)')+"'
")
    fhout.write("]
")
    print(content)
    contents.append(content)

fhout.close()