继续挑战
第4题地址linkedlist.php
- 网页标题是
follow the chain - 图片是小人锯东西❓❓❓
惯例打开网页源码view-source，发现注释文字：
urllib may help. DON’T TRY ALL NOTHINGS, since it will never end. 400 times is more than enough.
分析一下这段话的意思。首先提示urllib会对我们有帮助，还说400次足够了，还有NOTHINGS是个什么东西，为什么要试400次？
在愁眉莫展的时候发现源码里面还有一个超链接，原来点击图片是会链接到一个页面nothing=12345的
and the next nothing is 44827
这样的话，nothing是个什么东西，还有为什么400次就很明了了。
这里简单说下网页中
?的意思：
?表示GET方法，后面用key1=value1&key2=value2[&...]的方式传递参数
然后后台使用php（本题）、asp、js得方式来进行处理并返回GET结果
就不废话了，我们先试个400次，不过我们用requests不用urllib，因为前者要好用一些：
import re
import requests
url = 'http://www.pythonchallenge.com/pc/def/linkedlist.php?nothing='
nothing = '12345'
with requests.Session() as sess:
for i in range(400):
response = sess.get(url + nothing).text
result = re.findall(r'next nothing is (\d+)', response)
if not result:
print('nothing =', nothing)
print(response)
break
nothing = result[0]
nothing = 16044
Yes. Divide by two and keep going.
有意思的是，在第二次的时候会提示Your hands are getting tired，正好说明了不建议手工操作:D
在若干次之后停了下来，显示
Divide by two and keep going.
也很好理解，我们继续。
import re
import requests
url = 'http://www.pythonchallenge.com/pc/def/linkedlist.php?nothing='
nothing = str(16044 / 2)
with requests.Session() as sess:
for i in range(400):
response = sess.get(url + nothing).text
result = re.findall(r'next nothing is (\d+)', response)
if not result:
print('nothing =', nothing)
print(response)
break
nothing = result[0]
nothing = 66831
peak.html
若干次之后也停了下来（中间出现了一次There maybe misleading numbers in the text. One example is 82683. Look only for the next nothing and the next nothing is 63579，说明不能光区配数字来取结果，不然就是
nothing=82683：
You've been misleaded to here. Go to previous one and check.）。
看一下结果，是peak.html，打开之后到了下一题！