headers = {
	'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3',
	'Accept-Encoding': 'gzip, deflate, br',
	'Accept-Language': 'ru,en;q=0.9',
        'User-Agent':'Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 YaBrowser/19.6.3.185 Yowser/2.5 Safari/537.36',
        'Connection':'keep-alive',
        'Content-Type': 'text/html',
        'X-Requested-With': 'XMLHttpRequest'
}
r = requests.get('https://mysite.com/razdel_sayta/', headers=headers, params={'b': '1'})
print(r.url)