python：invalid character in identifier？

显示倒数第二行的第一个header为无效字符

#查看网页源代码
import requests
url="https://avg.163.com/creator/school/course/141"
headers={"User-Agent":"Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/70.0.3538.25 Safari/537.36 Core/1.70.3775.400 QQBrowser/10.6.4209.400"}
#模拟浏览器的访问请求
res=requests.get(url，headers=headers).text
print(res)

requests.get(url， headers=headers).text

headers前面的逗号应该是英文逗号，编程语言的标点符号一定要用英文的

res=requests.get(url，headers=headers).text
->
res=requests.get(url, headers=headers).text