August 2022
Beginner to intermediate
463 pages
9h 22m
Chinese
Content preview from Tableau Prep即学即用
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.
28
｜
第
3
章
图
3
-
1
：Chin & Beard Suds 公司的数据样本
3.1
阶段
1
：了解你的数据
如果不了解你的数据集的现状，将无法提供所需要的结果。对于小型数据集，有时
很容易形成这种理解和相应的规划。对于较大的数据集，规划过程可能需要较长的
时间，但这个过程显得尤为重要，因为个人的记忆中只能容纳那么多信息。表
3-1
展示了在数据集中需要注意的问题（使用图
3-1
中的样本数据）。
表
3
-
1
：数据集的注意事项
关注的内容
我们的示例
列
、
行
、
交叉表
：
数据如何组织
所有主流浏览器都原生支持这种方式
列头和列
：
是否都像预期的那样
月的列头最好是一列
，
其数值放在单独的一
列中
数据类型
：
每列中存在什么类型的数据
？
有两个文本值
，
但后面的每一列都是一个数
每列中应该只有一种数据类型
。
数据类型包括
字值
strings
（
字符串
，
由字母及数字字符构成
）、
numbers
（
数字
）、
dates
（
日期
）
和
Boolean
（
true
真
/false
假
）
行的粒度
：
每一行代表什么内容
每一行都是特定日期内商店里销售的不同产
品
数据点
：
有没有缺失的数据点
当前没有数据点存在
，
所以我们在这个例子
中可以不考虑这个因素
记录数量
：
数据集是否有你所期望的观察数量
有三个分支机构和两个产品
，
总共有六行数
据
。
四个月的数据
，
有
24
个值
业务
/
组织规则
：
数据集是否有应该遵守的规则
在这个例子中
，
Lewisham
应该被记录为一个
分支
，
而不是两个
快速绘制数据集的草图通常有助于思考和回答这些问题。图
3-2
展示了我们如何绘
制样本数据的草图。
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Read now
Unlock full access
More than 5,000 organizations count on O’Reilly
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.