转载的，就是为了学习用多点思路

# !/usr/bin/env python
# -*- coding:utf-8 -*-
"""12306登陆"""
import requests
import base64
import re
def get_point(index):
map = {
'1': '37,46',
'2': '110,46',
'3': '181,46',
'4': '253,46',
'5': '37,116',
'6': '110,116',
'7': '181,116',
'8': '253,116',
}
index = index.split(',')
temp = []
for item in index:
temp.append(map[item])
return ','.join(temp)

# 实例化一个Session
session = requests.Session()  # 自动的处理cookie
headers = {
'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/67.0.3396.99 Safari/537.36'
}
session.headers.update(headers)

# 伪装成浏览器
# 1. 访问 获取cookie
cookie_url = 'https://kyfw.12306.cn/otn/login/conf'
response = session.get(cookie_url)
# 2. 下载验证码
captcha_url = 'https://kyfw.12306.cn/passport/captcha/captcha-image64?login_site=E&module=login&rand=sjrand&1541686714134&callback=jQuery19109992892609908492_1541686371355&_=1541686371356'
response = session.get(captcha_url)
data = response.text
img_base64 = re.findall(r'"image":"(.*?)"', data)[0]
# img_base64 = 'data:image/jpg;base64,' + img_base64
# 转换成二级制数据
img_bytes = base64.b64decode(img_base64)
# 写到文件
with open('captcha.jpg', 'wb') as f:
f.write(img_bytes)

# 3校验验证码
check_captcha = 'https://kyfw.12306.cn/passport/captcha/captcha-check?callback=jQuery19109992892609908492_1541686371355&rand=sjrand&login_site=E&_=1541686371358'
response = session.get(check_captcha, params={'answer': get_point(input('请输入正确的序号>>>:'))} )#验证码输入，请输入正确验证码的序号（不是坐标），序号之间以,号隔开，验证码在程序目录下
res = response.text
code = re.findall(r'"result_code":"(.*?)"', res)[0]
if code == '4':
print('验证码校验成功')
# 4 校验用户名密码
login_url = 'https://kyfw.12306.cn/passport/web/login'
form_data = {
'username': '12306账号',#替换成自己的12306账号
'password': '12306密码',#替换成自己的12306密码
'appid': 'otn'
}
response = session.post(login_url, data=form_data)
res = response.json()
if res["result_code"] == 0:
print('用户名密码校验成功！')
# 5获取权限token
uamtk_url = 'https://kyfw.12306.cn/passport/web/auth/uamtk'
response = session.post(uamtk_url, data={'appid': 'otn'})
res = response.json()
if res["result_code"] == 0:
print('获取token成功')
# 6.校验 token
check_token_url = 'https://kyfw.12306.cn/otn/uamauthclient'
response = session.post(check_token_url, data={'tk': res['newapptk']})
print(response.text)