Python Beautiful Soup抓取和解析

Question

There is a Java Script page I am attempting to scrape with BeautifulSoup

bb2_addLoadEvent(function() {
    for ( i=0; i < document.forms.length; i++ ) {
        if (document.forms[i].method == 'post') {
            var myElement = document.createElement('input');
            myElement.setAttribute('type', 'hidden');
            myElement.name = 'bb2_screener_';
            myElement.value = '1568090530 122.44.202.205 122.44.202.205';
            document.forms[i].appendChild(myElement);
        }

I would like to obtain the value of "myElement.value", but I am not familiar with how to do so( If it is even possible with BeautifulSoup)

Ive tried :

soup = BeautifulSoup(a.text, 'html.parser')
h = soup.find('type')   ...('div') ... ('input') ... even ('var')
    print(soup)

and NO Luck :(

Is there a way of obtaining the value? If so how?

Answer 1

It would help to know more about the myElement.value across different pages. You might get away with a simple character set and lead string as shown in regex below. I would like to tighten it up but would need more examples ..... perhaps those number lengths are fixed and repeating ? ..... then something like p = re.compile(r"myElement\\.value = '(\\d{10}(?:(\\s\\d{3}\\.\\d{2}\\.\\d{3}\\.\\d{3}){2}))';") <= then take group 1.

import re

s = '''bb2_addLoadEvent(function() {
    for ( i=0; i < document.forms.length; i++ ) {
        if (document.forms[i].method == 'post') {
            var myElement = document.createElement('input');
            myElement.setAttribute('type', 'hidden');
            myElement.name = 'bb2_screener_';
            myElement.value = '1568090530 122.44.202.205 122.44.202.205';
            document.forms[i].appendChild(myElement);
        }'''

p = re.compile(r"myElement\.value = '([\d\s\.]+)';")
print(p.findall(s)[0])

---

@SIM also kindly proposed:

p = re.compile(r"value[^']+'([^']*)'"

Answer 2

If myElement.value = is static, this can be achieved with a simple regular expression:

value = re.compile(r"myElement\.value = '([^']+)'").search(str).group(1)

This matches myElement.value = ' , followed by non- ' characters, followed by another ' , where all the non- ' characters are captured in a group. Then the group(1) extracts the group from the match.

If the string may contain escaped ' s as well, eg:

myElement.value = 'foo \' bar';

then alternate \\. with [^'] :

myElement\.value = '((?:\\.|[^'])+)'

https://regex101.com/r/Tdarel/1