<?xml version="1.0" encoding="utf-8" ?><rss version="2.0"><channel><title><![CDATA[Timelessheart的博客]]></title><description><![CDATA[]]></description><link>https://blog.youkuaiyun.com/Timelessheart</link><language>zh-cn</language><generator>https://blog.youkuaiyun.com/</generator><copyright><![CDATA[Copyright &copy; Timelessheart]]></copyright><item><title><![CDATA[变量及变量的使用方法]]></title><link>https://blog.youkuaiyun.com/Timelessheart/article/details/119257132</link><guid>https://blog.youkuaiyun.com/Timelessheart/article/details/119257132</guid><author>Timelessheart</author><pubDate>Fri, 30 Jul 2021 22:31:38 +0800</pubDate><description><![CDATA[2.1 变量
变量常被描述为可用于储存的盒子，还有一种定义是变量是赋给值的标签，也可以说变量指向特定的值。
2.2 变量的使用
变量名只能包含字母、数字和下划线，变量名开头只能是字母或下划线打头，不能以数字开头
变量名不能包含空格，但可以用下划线分割单词
不要将python关键字和函数名作为变量名
变量名应简短并具有描述性

...]]></description><category></category></item><item><title><![CDATA[国内镜像源永久]]></title><link>https://blog.youkuaiyun.com/Timelessheart/article/details/119257066</link><guid>https://blog.youkuaiyun.com/Timelessheart/article/details/119257066</guid><author>Timelessheart</author><pubDate>Fri, 30 Jul 2021 22:23:39 +0800</pubDate><description><![CDATA[pip包管理器：

安装一个库: pip install 库的名字

默认失去官方国外网站下载，速度比较慢

国内镜像源：

清华：https://pypi.tuna.tsinghua.edu.cn/simple

阿里云：http://mirrors.aliyun.com/pypi/simple/

中国科技大学 https://pypi.mirrors.ustc.edu.cn/simple/

华中理工大学：http://pypi.hustunique.com/

山东理工大学：http://pypi.]]></description><category></category></item><item><title><![CDATA[pandas中的日期处理]]></title><link>https://blog.youkuaiyun.com/Timelessheart/article/details/108637012</link><guid>https://blog.youkuaiyun.com/Timelessheart/article/details/108637012</guid><author>Timelessheart</author><pubDate>Thu, 17 Sep 2020 10:50:09 +0800</pubDate><description><![CDATA[导入的模块
import numpy as np
import pandas as pd
from pandas import Series,DataFrame
from numpy import nan as NA
import time
from datetime import datetime
from datetime import timedelta
创建一个对象
time1=datetime(2020,8,17)
获取当前时间
now=datetime.now()
时间戳
time.time()]]></description><category></category></item><item><title><![CDATA[pandas描述统计-汇总计算-唯一值-值计数-成员资格-缺失值处理]]></title><link>https://blog.youkuaiyun.com/Timelessheart/article/details/108536584</link><guid>https://blog.youkuaiyun.com/Timelessheart/article/details/108536584</guid><author>Timelessheart</author><pubDate>Fri, 11 Sep 2020 17:03:39 +0800</pubDate><description><![CDATA[导入模块
import numpy as np
import pandas as pd
from pandas import Series,DataFrame
1.1汇总计算与描述统计pandas的Series和DataFrame
xxx.sum（）
xxx.mean()
xxx.max()
xxx.add()
df1=DataFrame(
    [
        [3,2,np.nan],
        [2,7,-5],
        [5,np.nan,np.nan],
        [7,]]></description><category></category></item><item><title><![CDATA[pandas-函数映射-排序-重复轴判断]]></title><link>https://blog.youkuaiyun.com/Timelessheart/article/details/108528298</link><guid>https://blog.youkuaiyun.com/Timelessheart/article/details/108528298</guid><author>Timelessheart</author><pubDate>Fri, 11 Sep 2020 11:00:05 +0800</pubDate><description><![CDATA[需要用到的模块
import numpy as np 
import pandas as pd
from pandas import Series,DataFrame
1.1 函数应用和映射
df1=DataFrame(
np.random.choice(range(20),size=(4,3),replace=False),
index=list('ABCD'),
columns=list('abc'))

#使用numpy的函数操作axis=0跨行操作
np.sum(df1,axis=0)
np.one]]></description><category></category></item><item><title><![CDATA[pandas-索引操作-算数运算]]></title><link>https://blog.youkuaiyun.com/Timelessheart/article/details/108461933</link><guid>https://blog.youkuaiyun.com/Timelessheart/article/details/108461933</guid><author>Timelessheart</author><pubDate>Tue, 08 Sep 2020 10:10:01 +0800</pubDate><description><![CDATA[导入模块
import numpy as np 
import pandas as pd
from pandas import Series,DataFrame
1.索引
#创建一个s1
s1=Series(range(1,5),index=list('ABCD'))
#索引不可修改否则报错 如下
s1.index[0]='a'
#但是可以整体替换
s1.index=list('abcd')
索引的删除
obj.drop('index,axis=0,inplace=False)默认删除行索引
obj.dro]]></description><category></category></item><item><title><![CDATA[python中pandas基本数据类型-2]]></title><link>https://blog.youkuaiyun.com/Timelessheart/article/details/108456173</link><guid>https://blog.youkuaiyun.com/Timelessheart/article/details/108456173</guid><author>Timelessheart</author><pubDate>Tue, 08 Sep 2020 09:24:33 +0800</pubDate><description><![CDATA[**以下的代码jupyter notebook 写出来的，在pycharm 里也是可以运行但是需要下载模块pandas和numpy **
通过字典中包含字典创建个DataFrame
dict_city={
	'shanghai':{2019:54000,2020:56000},
        'beijing':{2018:66666,2019:77777}
}
df_city=DataFrame(dict_city)
df_city
增加数据df.insert(loc,column,value,allo]]></description><category></category></item><item><title><![CDATA[python中pandas基本数据类型-1]]></title><link>https://blog.youkuaiyun.com/Timelessheart/article/details/108309657</link><guid>https://blog.youkuaiyun.com/Timelessheart/article/details/108309657</guid><author>Timelessheart</author><pubDate>Sun, 30 Aug 2020 20:31:20 +0800</pubDate><description><![CDATA[以下代码都是通过jupyter notebook 写的 在pycharm里也同样可以运行，
把想得到的结果print（）就可以了，例：s=pd.Series([4,-7,3,9]) print(s)
但是numpy和pandas模块需要下载，下载好就可以用了
Serise
	pandas.Series（）返回一个有index和values属性的数据对象

import pandas as pd#导入pandas模块 
import numpy as np
from pandas import Series,]]></description><category></category></item><item><title><![CDATA[python中的数字与字符串]]></title><link>https://blog.youkuaiyun.com/Timelessheart/article/details/108268926</link><guid>https://blog.youkuaiyun.com/Timelessheart/article/details/108268926</guid><author>Timelessheart</author><pubDate>Fri, 28 Aug 2020 21:59:13 +0800</pubDate><description><![CDATA[模块
import pandas
import operator 操作符模块
import math
import pandas as pd
import operator
import math
数字
#字符串的拼接
name='a'
sex='nan'
name+sex
#结果：anan

#求平方根
math.sqrt(4)
#结果：2.0

#自然数常量
math.e
#结果：2.718281828459045





...]]></description><category></category></item><item><title><![CDATA[Python面试题集锦]]></title><link>https://blog.youkuaiyun.com/Timelessheart/article/details/108045100</link><guid>https://blog.youkuaiyun.com/Timelessheart/article/details/108045100</guid><author>Timelessheart</author><pubDate>Sun, 16 Aug 2020 22:00:59 +0800</pubDate><description><![CDATA[Python是目前编程领域最受欢迎的语言。在本文中，我将总结Python面试中最常见的50个问题。每道题都提供参考答案，希望能够帮助你在2019年求职面试中脱颖而出，找到一份高薪工作。这些面试题涉及Python基础知识、Python编程、数据分析以及Python函数库等多个方面。
Q1、Python中的列表和元组有什么区别？
Q2、Python的主要功能是什么？
Python是一种解释型语言。与C语言等语言不同，Python不需要在运行之前进行编译。
Python是动态语言，当您声明变量或类似变量时，您不需]]></description><category></category></item><item><title><![CDATA[SPSS MODELER]]></title><link>https://blog.youkuaiyun.com/Timelessheart/article/details/107070560</link><guid>https://blog.youkuaiyun.com/Timelessheart/article/details/107070560</guid><author>Timelessheart</author><pubDate>Wed, 01 Jul 2020 19:36:20 +0800</pubDate><description><![CDATA[]]></description><category></category></item><item><title><![CDATA[power BI（power Query）]]></title><link>https://blog.youkuaiyun.com/Timelessheart/article/details/106796753</link><guid>https://blog.youkuaiyun.com/Timelessheart/article/details/106796753</guid><author>Timelessheart</author><pubDate>Tue, 16 Jun 2020 22:19:55 +0800</pubDate><description><![CDATA[]]></description><category></category></item><item><title><![CDATA[Excel基础（六）]]></title><link>https://blog.youkuaiyun.com/Timelessheart/article/details/106727574</link><guid>https://blog.youkuaiyun.com/Timelessheart/article/details/106727574</guid><author>Timelessheart</author><pubDate>Sat, 13 Jun 2020 08:44:29 +0800</pubDate><description><![CDATA[]]></description><category></category></item><item><title><![CDATA[Excel基础（五）]]></title><link>https://blog.youkuaiyun.com/Timelessheart/article/details/106528520</link><guid>https://blog.youkuaiyun.com/Timelessheart/article/details/106528520</guid><author>Timelessheart</author><pubDate>Wed, 03 Jun 2020 17:08:38 +0800</pubDate><description><![CDATA[]]></description><category></category></item><item><title><![CDATA[Excel基础（四）]]></title><link>https://blog.youkuaiyun.com/Timelessheart/article/details/106480643</link><guid>https://blog.youkuaiyun.com/Timelessheart/article/details/106480643</guid><author>Timelessheart</author><pubDate>Mon, 01 Jun 2020 20:00:40 +0800</pubDate><description><![CDATA[]]></description><category></category></item><item><title><![CDATA[Excel基础（三）]]></title><link>https://blog.youkuaiyun.com/Timelessheart/article/details/106431267</link><guid>https://blog.youkuaiyun.com/Timelessheart/article/details/106431267</guid><author>Timelessheart</author><pubDate>Fri, 29 May 2020 19:01:05 +0800</pubDate><description><![CDATA[]]></description><category></category></item><item><title><![CDATA[Excel基础（二）]]></title><link>https://blog.youkuaiyun.com/Timelessheart/article/details/106396208</link><guid>https://blog.youkuaiyun.com/Timelessheart/article/details/106396208</guid><author>Timelessheart</author><pubDate>Thu, 28 May 2020 08:55:47 +0800</pubDate><description><![CDATA[]]></description><category></category></item><item><title><![CDATA[Excel基础（一）]]></title><link>https://blog.youkuaiyun.com/Timelessheart/article/details/106372391</link><guid>https://blog.youkuaiyun.com/Timelessheart/article/details/106372391</guid><author>Timelessheart</author><pubDate>Wed, 27 May 2020 08:51:47 +0800</pubDate><description><![CDATA[]]></description><category></category></item><item><title><![CDATA[数据分析（一）]]></title><link>https://blog.youkuaiyun.com/Timelessheart/article/details/106353537</link><guid>https://blog.youkuaiyun.com/Timelessheart/article/details/106353537</guid><author>Timelessheart</author><pubDate>Tue, 26 May 2020 12:25:24 +0800</pubDate><description><![CDATA[什么是数据分析

 简单的说数据分析就是对数据进行分析

 专业的说数据分析是指用适当统计分析方法对收集来的大量数据进行分析，将他们加以汇总和理解并消化，以求最大化的开发数据功能，发挥数据作用

 实际应用中数据分析可以帮助人们做出判断，以便采取适当的行动

数据分析的价值

 从杂乱无章的数据中将信息集中，提炼，分析出研究对象的内在规律，这也是克敌制胜的秘诀之一。

 数据分...]]></description><category></category></item><item><title><![CDATA[MySQL单词总结4]]></title><link>https://blog.youkuaiyun.com/Timelessheart/article/details/106316658</link><guid>https://blog.youkuaiyun.com/Timelessheart/article/details/106316658</guid><author>Timelessheart</author><pubDate>Sun, 24 May 2020 16:23:39 +0800</pubDate><description><![CDATA[1.Program Files程序文件
2. path路径
3. localhost本地服务器
4. Access denied for user拒绝用户访问
5. using password使用密码
6.  show databases显示数据库
7.  information信息
8. performance性能
9.  schema架构
10.  6 rows in set   6行在集合中
11.  You have an error in your SQL syntax；SQL语法中有错误
12]]></description><category></category></item></channel></rss>