<?xml version="1.0" encoding="utf-8" ?><rss version="2.0"><channel><title><![CDATA[qianshanL的博客]]></title><description><![CDATA[]]></description><link>https://blog.youkuaiyun.com/qianshanL</link><language>zh-cn</language><generator>https://blog.youkuaiyun.com/</generator><copyright><![CDATA[Copyright &copy; qianshanL]]></copyright><item><title><![CDATA[python练习题]]></title><link>https://blog.youkuaiyun.com/qianshanL/article/details/102653317</link><guid>https://blog.youkuaiyun.com/qianshanL/article/details/102653317</guid><author>qianshanL</author><pubDate>Sun, 20 Oct 2019 20:42:53 +0800</pubDate><description><![CDATA[1、python3压缩字符串
通过Python实现字符串压缩算法，如下：
qqawwwzz 经过压缩后变成 2qa3w2z
代码如下：
word=input("请输入一个字符串：")
import itertools
l = [(k, len(list(g))) for k, g in itertools.groupby(word)]
print(l)
s = ''
for i in l:
   ...]]></description><category></category></item><item><title><![CDATA[Oracle日期操作(to_number,trunc)]]></title><link>https://blog.youkuaiyun.com/qianshanL/article/details/97111724</link><guid>https://blog.youkuaiyun.com/qianshanL/article/details/97111724</guid><author>qianshanL</author><pubDate>Wed, 24 Jul 2019 11:16:16 +0800</pubDate><description><![CDATA[如果不熟悉日期操作，获取相应信息的时候，要写很复杂的语句，下面举例几个常用的取值方式：
select hiredate,
to_number(to_char(hiredate,'hh24')) 时,
to_number(to_char(hiredate,'mi')) 分,
to_number(to_char(hiredate,'ss')) 秒,
to_number(to_char(hiredate...]]></description><category></category></item><item><title><![CDATA[爬取的代码]]></title><link>https://blog.youkuaiyun.com/qianshanL/article/details/90443820</link><guid>https://blog.youkuaiyun.com/qianshanL/article/details/90443820</guid><author>qianshanL</author><pubDate>Fri, 24 May 2019 15:50:45 +0800</pubDate><description><![CDATA[爬取网页的通用代码框架：
import requests
def getHTMLText(url):
    try:
        r=requests.get(url,timeout=30)
        r.raise_for_status()#如果状态不是200，引发HTTPError异常
        r.encoding=r.apparent_encoding
        r...]]></description><category></category></item><item><title><![CDATA[SQL中的条件判断函数CASE WHEN,和IF的用法]]></title><link>https://blog.youkuaiyun.com/qianshanL/article/details/89459202</link><guid>https://blog.youkuaiyun.com/qianshanL/article/details/89459202</guid><author>qianshanL</author><pubDate>Mon, 22 Apr 2019 20:52:54 +0800</pubDate><description><![CDATA[条件判断函数也成为控制流程函数，根据满足的条件的不同，执行相应的流程。MYSQL中进行条件判断的函数有IF,IFNULL,CASE。本文将分别介绍各个函数的用法。
1、IF( expr , v1 , v2 )
如果表达式expr的值为TURE,则IF()的返回值为v1；
如果表达式expr是值为FALSE,则IF()的返回值为v2。
IF()的返回值为数字值或者字符串，具体情况视其所在语境而定。
...]]></description><category></category></item><item><title><![CDATA[UNIX时间戳函数]]></title><link>https://blog.youkuaiyun.com/qianshanL/article/details/89458551</link><guid>https://blog.youkuaiyun.com/qianshanL/article/details/89458551</guid><author>qianshanL</author><pubDate>Mon, 22 Apr 2019 19:03:33 +0800</pubDate><description><![CDATA[UNIX_TIMESTAMP(date)若无参数调用，则返回一个Unix时间戳（‘1970-01-01 00:00:00’）作为无符号整数。
例1：使用UNIX_TIMESTAMP函数返回UNIX格式的时间戳，输入语句如下：
mysql&gt; select unix_timestamp(),unix_timestamp(now()),now();


而FROM_UNIXTIME(date)函数...]]></description><category></category></item></channel></rss>