import pymysql.cursors
import numpy as np
import time

connection = pymysql.connect(host='localhost',
                             user='root',
                             password='sql',
                             db='test',
                             charset='utf8mb4',
                             cursorclass=pymysql.cursors.DictCursor)

try:
    with connection.cursor() as cursor:
        cursor.execute("truncate table test.histtest")
        for retry in range (0,300):
            for row in np.random.randn(100, 4):
                cursor.execute("insert into test.histtest values(null, %s, %s, %s, %s)", (str(row[0]),str(row[1]),str(row[2]),str(row[3])))

            cursor.execute("delete from test.histtest where id = (select min(id) from test.histtest)")
            connection.commit()
            time.sleep(1)

finally:
    connection.close()