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Python3.x版本中新的字符串格式化方法

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Jun 06, 2016 am 11:25 AM

String formatting

我们知道Python3.x引入了新的字符串格式化语法。不同于Python2.x的

代码如下:

"%s %s "%(a,b)

Python3.x是

代码如下:

"{0} {1}".format(a,b)

今天我在用MySQLdb时，需要用带参数的

代码如下:

cursor.execute(sql,param)

语句来完成SQL操作。被其他文章的陈旧说法给误导，用了

代码如下:

cursor.execute('insert into test values(%s,%s,%s)',param)

其中param是一个元组，表示要插入的数据，元组中的各个元素即是数据库中各列的值。
但是执行起来总是会抛出数据库异常，错误信息：

代码如下:

【1064】You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near'(%s,%s,%s)'at line……（以下省略）。

其实只要改成这样就好：

代码如下:

cursor.execute('insert into test values({0},{1},{2})',param)

实话说，Python3为了填上Python2的各坑导致了不向下兼容，使得学习Python3的成本提高了不少。但是为了不阻碍科技发展、社会进步，我还是毅然决然投身新版本……

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