import requests
import json
class requests_webdriver:
def init(self):
self.driver=self.chrome_driver()
def chrome_driver(self):
url = 'http://127.0.0.1:4444/wd/hub/session/'
data = json.dumps({
‘desiredCapabilities’: {
‘browserName’: ‘chrome’
}
})
res = requests.post(url,data).json()
session = res[‘sessionId’]
driver = url + session
return driver

def get_url(self,url):
    base_url=self.driver+'/url'
    data=json.dumps({
        "url":url
    })
    requests.post(base_url,data)

def find_element_by_id(self,value):
    base_url=self.driver+'/element'
    data = json.dumps({
        "using":"name",
        "value":value
    })
    res=requests.post(base_url,data).json()
    print(res)

if name == ‘main’:
requests_driver = requests_webdriver()
requests_driver.get_url(“https://www.imooc.com/user/newlogin/from_url/”)
requests_driver.find_element_by_id(“email”)
老师上面是我写的代码，我执行后sessionId为None,这是正常的还是已经出错了，麻烦帮我看下。

C:\Users\Administrator\AppData\Local\Programs\Python\Python36\python.exe F:/python_web/study3/study3_12.py
{‘state’: ‘success’, ‘sessionId’: None, ‘class’: ‘org.openqa.selenium.remote.Response’, ‘value’: {‘element-6066-11e4-a52e-4f735466cecf’: ‘8d0434c2-634e-4b2f-a52a-5ec410a9ba7a’}, ‘status’: 0}

Process finished with exit code 0