Python operation database

import pymysql 
# port default 3306int type 
#1, connect database account, password, IP, port number, database 
#2, create cursor 
#3, execute sql 
#4, get result 
#5, close cursor 
#6, close connection 
conn=pymysql .connect( 
    host='xxx.xx.x.xx',user='xxx',passwd='123456', 
    port=3306,db='xxx',charset='utf8'#charset must write utf8 
) 
cur= conn.cursor()#Create a cursor 
# cur.execute('insert into stu (id,name,sex) VALUES(1,"Xiaobai","Female");')#Execute sql 
# conn.commit()# In addition to the query, submit 
cur.execute("select * from stu")# 
sql=cur.fetchall()#Get all the returned results 
print(sql) 
cur.close()#Close the cursor 
conn.close()#Close the connection 


------Operate database functions

def my_db(host,user,passwd,db,sql,port=3306,charset='utf8'):
    import pymysql
    coon=pymysql.connect(user=user,passwd=passwd,host=host,port=port,db=db,charset=charset)
    cur=coon.cursor()#建立游标
    cur.execute(sql)#执行sql
    if sql.strip()[0:6].upper()=='SELECT':
        res=cur.fetchall()
    else:
        coon.commit()
        res='ok'
    cur.close()
    coon.close()
    return res