How to extract URL from an HTML

Question

I'm a newbie in web scraping. I do as below

from urllib.request import urlopen
from bs4 import BeautifulSoup
import re
html = urlopen("http://chgk.tvigra.ru/letopis/?2016/2016_spr#27mar")
soup = BeautifulSoup(html, "html.parser")
res = soup.find_all('a', {'href': re.compile("r'\b?20\b'")})
print (res)

and get

[]

My goal is this fragment

<script language="javascript" type="text/javascript">
cont = new Array();
count = new Array();
for (i=1979; i <=2015; i++){count[i]=0};
cont[1979] =    "<li><a href='?1979_1#24jan'>24 января</a>" +  

..............

cont[2016] =    "<li><a href='?2016/2016_spr#cur'>Весенняя серия</a>" +
        "<li><a href='?2016/2016_sum#cur'>Летняя серия</a>" +
        "<li><a href='?2016/2016_aut#cur'>Осенняя серия</a>" +
        "<li><a href='?2016/2016_win#cur'>Зимняя серия</a>";

And i try to get the result like this

'?2016/2016_spr#cur' 
'?2016/2016_sum#cur'
'?2016/2016_aut#cur'
'?2016/2016_win#cur'

From 2000 to this moment (so '20' in "r'\b?20\b'" is for this reason). Can you help me, please?

Answer 1

Preliminaries:

>>> import requests
>>> import bs4
>>> page = requests.get('http://chgk.tvigra.ru/letopis/?2016/2016_spr#27mar').content
>>> soup = bs4.BeautifulSoup(page, 'lxml')

Having done this it might seem that the most straightforward way of identifying the script element might be to use this:

>>> scripts = soup.findAll('script', text=bs4.re.compile('cont = new Array();'))

However, scripts proves to be an empty list. (I don't know why.)

The basic approach works, if I choose a different target within the script but it would appear the it's unsafe to depend on the exact formatting of the content of Javascript script element.

>>> scripts = soup.find_all(string=bs4.re.compile('i=1979'))
>>> len(scripts)
1

Still, this might be good enough for you. Please just notice that the script has the change function at the end to be discarded.

A safer approach might be to look for the containing table element, then the second td element within that and finally the script within that.

>>> table = soup.find_all('table', class_='common_table')
>>> tds = table[0].findAll('td')[1]
>>> script = tds.find('script')

Again, you will need to discard function change.