If you want to open it automatically with a browser, you can try the suggestion from the guy upstairs:

Selenium is a famous automated testing tool based on webdriver, which can easily solve the poster's problem.

For example, the example I gave below can fulfill your needs and simulate logging in to Renren

# -*- coding:utf-8 -*-

from selenium import webdriver
from selenium.webdriver.support.wait import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC
from selenium.common.exceptions import NoSuchElementException
from selenium.webdriver.common.by import By

wd = webdriver.Firefox()
wd.get("http://www.renren.com")
wd.maximize_window()

try:
    """这段可以查看selenium的源码,属于smart wait"""
    email = WebDriverWait(wd,timeout=10).until(EC.presence_of_element_located((By.ID,'email')),message=u'元素加载超时!')
    email.send_keys("*** 你的账号 ***")
    passwd = WebDriverWait(wd,timeout=10).until(EC.presence_of_element_located((By.ID,'password')),message=u'元素加载超时!')
    passwd.send_keys("*** 你的密码 ***")
    wd.find_element_by_id("login").click() #点击登录
except NoSuchElementException as e:
    print e.message

Thanks for reading.

Use selenium, the library of python, which is powerful and makes building automated tests stress-free