mysql数据库无法启动怎么解决

[mysqld]
port = 3306
datadir = /var/lib/mysql
socket = /var/run/mysqld/mysqld.sock

sudo netstat -tuln | grep 3306

sudo chown -R mysql:mysql /var/lib/mysql
sudo chmod -R 755 /var/lib/mysql

sudo mysqlcheck --all-databases --auto-repair

import mysql.connector

try:
    connection = mysql.connector.connect(
        host="localhost",
        user="yourusername",
        password="yourpassword",
        database="yourdatabase"
    )
    if connection.is_connected():
        db_Info = connection.get_server_info()
        print("Connected to MySQL Server version ", db_Info)
        cursor = connection.cursor()
        cursor.execute("select database();")
        record = cursor.fetchone()
        print("You're connected to database: ", record)
except mysql.connector.Error as e:
    print("Error while connecting to MySQL", e)
finally:
    if (connection.is_connected()):
        cursor.close()
        connection.close()
        print("MySQL connection is closed")