from selenium import webdriver
from selenium.webdriver.common.keys import Keys

browser = webdriver.Firefox()
browser.get('http://www.acquirersmultiple.com/login/')



#login_user = browser.find_element_by_css_selector('.rcp_login_data > p:nth-child(1) > input:nth-child(2)')
username = browser.find_element_by_id("rcp_user_login")
password = browser.find_element_by_id('rcp_user_pass')

username.send_keys("SomeUser")
password.send_keys("P4s5word")

//form[@id='rcp_login_form']//*[@name='rcp_user_login']
//form[@id='rcp_login_form']//*[@name='rcp_user_pass']

browser.find_element_by_id('rcp_login_submit').click()