"Access denied for user 'root'@'localhost'" during pymysql.connections

I tried to set up a LAMP server by following this article. It was set up without errors and I can “ssh root@localhost” with my password. But when I was ready to test it by going to http://my_server_ip using Firefox, it gave me a sequence of function calls leading up to the error: In /var/www/test/index.py 15 user=‘root’, 16 passwd=‘my_passwd’, => 17 host=‘localhost’) 18 c = conn.cursor() 19 host undefined In in Connect(*args=(), **kwargs={‘db’: ‘example’, ‘host’: ‘localhost’, ‘passwd’: ‘my_passwd’, ‘user’: ‘root’}) 88 “”" 89 from .connections import Connection => 90 return Connection(*args, **kwargs) 91 92 from . import connections as _orig_conn Connection = <class ‘pymysql.connections.Connection’>, args = (), kwargs = {‘db’: ‘example’, ‘host’: ‘localhost’, ‘passwd’: ‘my_passwd’, ‘user’: ‘root’} … 697 self._sock = None 698 else: => 699 self.connect() 700 701 def _create_ssl_ctx(self, sslp): self = <pymysql.connections.Connection object>, self.connect = <bound method Connection.connect of <pymysql.connections.Connection object>> … errorclass = <class ‘pymysql.err.InternalError’>, errno = 1698, errval = “Access denied for user ‘root’@‘localhost’”

InternalError: (1698, “Access denied for user ‘root’@‘localhost’”)

Can you please help me with this?