mysql - 大神帮忙看下20行的python代码,文件io和数据库插入太慢

Question

新学python,在做一个把爬虫爬下来的股票数据从文件插入到mysql数据库,速度很慢,不知道瓶颈是文件处理还是sql插入问题,望大神不吝赐教,感激不尽!

# encoding: utf-8
#!/usr/bin/python

import MySQLdb
import os
db = MySQLdb.connect(host="localhost",user="root",passwd="4242",\
        db="STOCKS", charset="utf8", use_unicode=True)
cursor = db.cursor()
files = os.listdir("shanghaiHistory")
for fileName in files:
    print "start insert " + fileName
    isTheFirstLine = True
    for line in open("shanghaiHistory/" + fileName):
        if isTheFirstLine:
            isTheFirstLine = False
            continue
        lineList = line.split(',')
        lineList.insert(0,fileName[:6])
        sql = "insert into shanghaiHistory(Code,Date,Open,High,Low,Close,Volume,AdjClose)\
                values ('%s','%s','%s','%s','%s','%s','%s','%s')" % tuple(lineList)
        try:
            cursor.execute(sql)
            db.commit()
        except:
            db.rollback()
db.close()

文件格式是形如:

Date,Open,High,Low,Close,Volume,Adj Close
2012-12-21,0.9151,0.9151,0.9151,0.9151,000,0.9151
2012-12-20,0.896,0.898,0.896,0.898,22924300,0.898
2012-12-19,0.895,0.898,0.895,0.897,37858100,0.897
2012-12-18,0.896,0.896,0.895,0.896,43542500,0.896
2012-12-17,0.895,0.897,0.895,0.896,41877700,0.896
2012-12-14,0.895,0.897,0.894,0.897,35734700,0.897
2012-12-13,0.894,0.896,0.894,0.895,11613800,0.895
2012-12-12,0.89,0.895,0.89,0.894,26586500,0.894

两个多小时才插入45W条数据,怎么才能提速一点呢.

Answer 1

很常识性的优化：批量插入，然后再提交，而不是插一条提交一条。

另一个常识性的优化：使用 executemany 来一次执行多条（但也不要太多）行的插入。

最后，但是也是非常重要的，请尽量不要自己拼接 SQL 语句！.execute 方法可以接受两个参数，第一个是 SQL 模板，第二个是参数值的 tuple。加粗文字