<?xml version="1.0" encoding="utf-8" ?><rss version="2.0"><channel><title><![CDATA[lhjcomputer的博客]]></title><description><![CDATA[]]></description><link>https://blog.youkuaiyun.com/lhjcomputer</link><language>zh-cn</language><generator>https://blog.youkuaiyun.com/</generator><copyright><![CDATA[Copyright &copy; lhjcomputer]]></copyright><item><title><![CDATA[Redis中string底层实现原理]]></title><link>https://blog.youkuaiyun.com/lhjcomputer/article/details/149618222</link><guid>https://blog.youkuaiyun.com/lhjcomputer/article/details/149618222</guid><author>lhjcomputer</author><pubDate>Wed, 08 Oct 2025 21:08:14 +0800</pubDate><description><![CDATA[Redis是基于C语言进行开发的。Redis字符串并没有采取C语言字符串，而是基于简单动态字符串的抽象类型(SDS)。SDS是Redis为了提高字符串操作性能而设计的一种数据结构，相比于标准C语言中的字符串，SDS提供了更多特性和更高效的内存管理。]]></description><category></category></item><item><title><![CDATA[SQLServer联合主键、联合索引]]></title><link>https://blog.youkuaiyun.com/lhjcomputer/article/details/149662773</link><guid>https://blog.youkuaiyun.com/lhjcomputer/article/details/149662773</guid><author>lhjcomputer</author><pubDate>Sun, 27 Jul 2025 00:35:54 +0800</pubDate><description><![CDATA[在上述实例中，index_name是索引的名称，table_name是表的名称，olumn1, column2, column3是需要包含在索引中的列名。联合索引遵循最左匹配原则，即索引的第一列被视为最重要的列，其次是第二列，以此类推。答：建立(a, c, b )的联合索引，a和c是等值条件，能快速的过滤数据，b是范围查询，放在最后，避免阻断后面的字段。答：索引不能覆盖SQL所有查询字段，a不在(b,c)的联合索引中，所以在查询数据，还需要回表去查询，去主键索引中去查。注：联合主键的列需要限制非空约束。]]></description><category></category></item><item><title><![CDATA[Pyinstaller 打包发布经验总结]]></title><link>https://blog.youkuaiyun.com/lhjcomputer/article/details/119349989</link><guid>https://blog.youkuaiyun.com/lhjcomputer/article/details/119349989</guid><author>lhjcomputer</author><pubDate>Tue, 03 Aug 2021 15:11:40 +0800</pubDate><description><![CDATA[在使用Pyinstaller打包Python项目遇到大量的坑，本片文章总结实践得到的Pyinstaller打包经验，记录并防止以后忘记。本文的例子为Python3.7代码，Pyinstaller4.25，在Centos 7.0下打包。

本文

Pyinstaller基本使用方法

Pyinstaller可以通过简单的命令进行python代码的打包工作，其基本的命令为：


pyinstaller -option xxx.py

这边只介绍用到的option：

...]]></description><category></category></item><item><title><![CDATA[Python str islower()方法]]></title><link>https://blog.youkuaiyun.com/lhjcomputer/article/details/118494586</link><guid>https://blog.youkuaiyun.com/lhjcomputer/article/details/118494586</guid><author>lhjcomputer</author><pubDate>Mon, 05 Jul 2021 17:31:20 +0800</pubDate><description><![CDATA[描述

islower函数检测字符串中字母是否都是小写字母。若全部的字母都是是由小写字母组成的，则返回True，否则返回False。islower函数没有参数。

语法


str.islower()

举例

1. 仅包含字母字符


test_1 = "this is test.1"
print(test_1.islower())

结果为


True

2. 包含数字、字符和符号


test_1 = "this is test"
test_2 = "this is ...]]></description><category></category></item><item><title><![CDATA[Python str isdigit()方法]]></title><link>https://blog.youkuaiyun.com/lhjcomputer/article/details/118494483</link><guid>https://blog.youkuaiyun.com/lhjcomputer/article/details/118494483</guid><author>lhjcomputer</author><pubDate>Mon, 05 Jul 2021 17:19:40 +0800</pubDate><description><![CDATA[描述

isdigit函数检测字符串中是否只包含数字字符。若全部是由数字字符组成的字符串，则返回True，否则返回False。isdigit函数没有参数。

语法


str.isdigit()

举例

1. 仅包含数字字符


test1 = '565656511'
print(test1.isdigit())

结果为


True

2. 包含数字、字符和符号


test1 = '202133265'
test2 = '2021/07/05'
test3 = '.t...]]></description><category></category></item><item><title><![CDATA[问题记录：springboot项目里用MultipartFile获取前端传的file为null问题]]></title><link>https://blog.youkuaiyun.com/lhjcomputer/article/details/118339692</link><guid>https://blog.youkuaiyun.com/lhjcomputer/article/details/118339692</guid><author>lhjcomputer</author><pubDate>Tue, 29 Jun 2021 17:19:31 +0800</pubDate><description><![CDATA[在使用SpringBoot进行文件上传时，发现使用MultipartFile获取前端传的file一直为null，看了很多帖子一直说是springboot自带的org.springframework.web.multipart.MultipartFile和Multipart冲突。然后经过自己测试发现自己的并不是这个问题，后面发现是html中文件的name需要和


@RequestParam(value = "uploadFile",required = false

中的value想对应

前段代码：


]]></description><category></category></item><item><title><![CDATA[YOLO框架简述]]></title><link>https://blog.youkuaiyun.com/lhjcomputer/article/details/114369080</link><guid>https://blog.youkuaiyun.com/lhjcomputer/article/details/114369080</guid><author>lhjcomputer</author><pubDate>Thu, 04 Mar 2021 15:15:57 +0800</pubDate><description><![CDATA[YOLO（You Only Look Once）是一种基于深度神经网络的对象识别和定位算法，其最大的特点是运行速度很快，可以用于实时系统。现在YOLO已经发展到v3版本，不过新版本也是在原有版本基础上不断改进演化的，所以本文先分析YOLO v1版本。

  输入一张图片，要求输出其中所包含的对象，以及每个对象的位置（包含该对象的矩形框）。



对象识别和定位，可以看成两个任务：找到图片中某个存在对象的区域，然后识别出该区域中具体是哪个对象。对象识别这件事（一张图片仅包含一个对象，且基本占据图片的整个范..]]></description><category></category></item><item><title><![CDATA[opencv读取图片，显示、存储，放大、缩小图片以及转为灰度图片]]></title><link>https://blog.youkuaiyun.com/lhjcomputer/article/details/114316119</link><guid>https://blog.youkuaiyun.com/lhjcomputer/article/details/114316119</guid><author>lhjcomputer</author><pubDate>Wed, 03 Mar 2021 15:19:10 +0800</pubDate><description><![CDATA[1.读取图片，显示、存储，放大、缩小图片以及转为灰度图片


import cv2 as cv
img_path = "C:\\Users\\lenovo\\Desktop\\111.jpg"   #图片路径
img = cv.imread(img_path)                #以BGR三通道读取图片数据（三维数组）
img_gray = cv.imread(img_path,cv.IMREAD_GRAYSCALE)  #以灰度图像的形式获取图像（二维数组）
cv.namedWindow("I]]></description><category></category></item><item><title><![CDATA[报错 ValueError: too many values to unpack (expected 2)]]></title><link>https://blog.youkuaiyun.com/lhjcomputer/article/details/110956741</link><guid>https://blog.youkuaiyun.com/lhjcomputer/article/details/110956741</guid><author>lhjcomputer</author><pubDate>Thu, 10 Dec 2020 16:56:10 +0800</pubDate><description><![CDATA[enc_output,enc_slf_attn  = self.slf_attn(user_embedding,item_input,item_input,mask  = slf_attn_mask)

实际上只有一个返回值，但是我却写了两个返回值，所以报错。

改正为


enc_output  = self.slf_attn(user_embedding,item_input,item_input,mask  = slf_attn_mask)

就好了

写代码的时候发现这个错误，记下以防以后忘记。
.]]></description><category></category></item><item><title><![CDATA[在PyCharm中设置背景颜色]]></title><link>https://blog.youkuaiyun.com/lhjcomputer/article/details/107562443</link><guid>https://blog.youkuaiyun.com/lhjcomputer/article/details/107562443</guid><author>lhjcomputer</author><pubDate>Fri, 24 Jul 2020 15:37:58 +0800</pubDate><description><![CDATA[1.打开PyCharm--&gt;File--&gt;Setting

.

2.更改为你想要的背景颜色




]]></description><category></category></item><item><title><![CDATA[PyCharm无法删除 无法编辑 无法复制]]></title><link>https://blog.youkuaiyun.com/lhjcomputer/article/details/107510770</link><guid>https://blog.youkuaiyun.com/lhjcomputer/article/details/107510770</guid><author>lhjcomputer</author><pubDate>Wed, 22 Jul 2020 12:36:38 +0800</pubDate><description><![CDATA[单栏，tools--去掉勾选的Vim Emulator这个仿真插件就好了。


]]></description><category></category></item><item><title><![CDATA[PyCharm单行多行注释快捷键以及取消注释快捷键]]></title><link>https://blog.youkuaiyun.com/lhjcomputer/article/details/107510726</link><guid>https://blog.youkuaiyun.com/lhjcomputer/article/details/107510726</guid><author>lhjcomputer</author><pubDate>Wed, 22 Jul 2020 12:33:01 +0800</pubDate><description><![CDATA[单行多行注释快捷键


ctrl+/

取消单行多行注释快捷键


ctrl+/


]]></description><category></category></item><item><title><![CDATA[PyCharm设置中文字体]]></title><link>https://blog.youkuaiyun.com/lhjcomputer/article/details/107510074</link><guid>https://blog.youkuaiyun.com/lhjcomputer/article/details/107510074</guid><author>lhjcomputer</author><pubDate>Wed, 22 Jul 2020 12:00:07 +0800</pubDate><description><![CDATA[PyCharm默认的字体是粗体和楷体的混合，看的很不方便

操作步骤

1.点击PyCharm中左上角的file--&gt;Editor.

2.打开下面的Color Scheme --&gt;Rightarrow--&gt;Color Scheme Font.

3.关闭“Show only monospaced fonts”选项，选择“Fallback font”，即可选择字体。建议选择有中文字体支持的字体，例如“Microsoft Yahei UI”
5.效果如图所示


...]]></description><category></category></item><item><title><![CDATA[错误：方法不会覆盖或实现超类型的方法（不同模块）]]></title><link>https://blog.youkuaiyun.com/lhjcomputer/article/details/106254747</link><guid>https://blog.youkuaiyun.com/lhjcomputer/article/details/106254747</guid><author>lhjcomputer</author><pubDate>Thu, 21 May 2020 12:53:58 +0800</pubDate><description><![CDATA[SOA架构的一个项目，一个模块定义了接口，另一个模块实现接口，在项目打包的时候，报了


方法不会覆盖或实现超类型的方法

的错误。

解决方法：正常的定义接口，编写实现类是没有问题，但是当是多模块时，需要将改变后的代码作为jar包“install”一下，这样仓库中才会有这个jar包，其它模块也才能引用。

在maven仓库中找到你定义的接口模块，重新install一下就行了
...]]></description><category></category></item><item><title><![CDATA[Ubuntu使用apt-get下载速度慢的解决方法]]></title><link>https://blog.youkuaiyun.com/lhjcomputer/article/details/105639406</link><guid>https://blog.youkuaiyun.com/lhjcomputer/article/details/105639406</guid><author>lhjcomputer</author><pubDate>Mon, 20 Apr 2020 17:29:15 +0800</pubDate><description><![CDATA[查看所用的源:sudo vim /etc/apt/sources.list
	由于安装的Ubuntu Server 16.04.1 LTS是英文版的，软件源就默认都是 us.archive.ubuntu.com（英国） 的，所以很慢。
	为了提高下载速度，将源改为国内的 cn.archive.ubuntu.com ，现在 cn.archive.ubuntu.com 指向阿里云的开源镜像站 mirr...]]></description><category></category></item><item><title><![CDATA[menmove]]></title><link>https://blog.youkuaiyun.com/lhjcomputer/article/details/104696848</link><guid>https://blog.youkuaiyun.com/lhjcomputer/article/details/104696848</guid><author>lhjcomputer</author><pubDate>Fri, 06 Mar 2020 15:21:03 +0800</pubDate><description><![CDATA[*-------------------------
memmove
语法:

#include &lt;string.h&gt;
void *memmove( void *to, const void *from, size_t count );

The memmove() function is identical to memcpy(), except that it works eve...]]></description><category></category></item><item><title><![CDATA[SpringMVC的工作流程]]></title><link>https://blog.youkuaiyun.com/lhjcomputer/article/details/104676838</link><guid>https://blog.youkuaiyun.com/lhjcomputer/article/details/104676838</guid><author>lhjcomputer</author><pubDate>Thu, 05 Mar 2020 16:06:47 +0800</pubDate><description><![CDATA[​​​​​

工作流程：




流程图解析：

：用户发送请求到前端控制器DispatcherServlet
	：前端控制器DispatcherServlet收到请求后调用处理器映射器HandlerMapping
	处理器映射器HandlerMapping找到具体的处理器(可以个根据xml、注解进行查找)一并返回给前端控制器(DispatcherServlet)
	：前端控制器调用处理器适配...]]></description><category></category></item><item><title><![CDATA[A - FatMouse' Trade]]></title><link>https://blog.youkuaiyun.com/lhjcomputer/article/details/81814074</link><guid>https://blog.youkuaiyun.com/lhjcomputer/article/details/81814074</guid><author>lhjcomputer</author><pubDate>Sat, 18 Aug 2018 23:08:34 +0800</pubDate><description><![CDATA[Submit Status Practice HDU 1009

Description

FatMouse prepared M pounds of cat food, ready to trade with the cats guarding the warehouse containing his favorite food, JavaBean.
The warehouse has N ro...]]></description><category></category></item><item><title><![CDATA[D - Elevator]]></title><link>https://blog.youkuaiyun.com/lhjcomputer/article/details/81743733</link><guid>https://blog.youkuaiyun.com/lhjcomputer/article/details/81743733</guid><author>lhjcomputer</author><pubDate>Thu, 16 Aug 2018 16:09:52 +0800</pubDate><description><![CDATA[Description

The highest building in our city has only one elevator. A request list is made up with N positive numbers. The numbers denote at which floors the elevator will stop, in specified order. I...]]></description><category></category></item><item><title><![CDATA[A - Let the Balloon Rise]]></title><link>https://blog.youkuaiyun.com/lhjcomputer/article/details/81742749</link><guid>https://blog.youkuaiyun.com/lhjcomputer/article/details/81742749</guid><author>lhjcomputer</author><pubDate>Thu, 16 Aug 2018 15:45:51 +0800</pubDate><description><![CDATA[Description

Contest time again! How excited it is to see balloons floating around. But to tell you a secret, the judges' favorite time is guessing the most popular problem. When the contest is over, ...]]></description><category></category></item></channel></rss>