Polish the Python code using sending requests in a session

Class Scanner.

#!/usr/bin/env python

import requests
import re
from urllib.parse import urljoin


class Scanner:
    def __init__(self, url, ignore_links):
        self.session = requests.Session()
        self.target_url = url
        self.target_links = []
        self.links_to_ignore = ignore_links

    def extract_links_from(self, url):
        response = self.session.get(url)
        return re.findall('(?:href=")(.*?)"', response.content.decode(errors='ignore'))

    def crawl(self, url=None):
        if url == None:
            url = self.target_url
        href_links = self.extract_links_from(url)
        for link in href_links:
            link = urljoin(url, link)

            if "#" in link:
                link = link.split("#")[0]

            if self.target_url in link and link not in self.target_links and link not in self.links_to_ignore:
                self.target_links.append(link)
                print(link)
                self.crawl(link)

Vuln_scanner.

#!/usr/bin/env python

import scanner

target_url = "http://10.0.0.45/dvwa/"
links_to_ignore = "http://10.0.0.45/dvwa/logout.php"

data_dict = {"username": "admin", "password": "password", "Login": "submit"}

vuln_scanner = scanner.Scanner(target_url, links_to_ignore)
vuln_scanner.session.post("http://10.0.0.45/dvwa/login.php", data=data_dict)

vuln_scanner.crawl()

The program runs fine.