August 2022
Beginner to intermediate
463 pages
9h 22m
Chinese
Content preview from Tableau Prep即学即用
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｜
261
处理多余字符
不单纯是数字的
Sales
（销售）记录，其值也应被转换为空值（见图
29-4
）。
图
29
-
4
：非数字值的 Sales（销售）记录也被转换为空值
带感叹号和数字
8
的字符串值仍然是字符串，但因为它们明显不同，所以在概况窗
格中被分割开来（见图
29-5
）。带有前导空格的条形值已经被
Tableau Prep
自然清
理掉了。它可以对某些数据源进行清理，但不是所有的数据源。
图
29
-
5
：在概况窗格中显示的多余字符
因此，为了使数据可以使用，必须在完成数据类型转换之前删除多余字符。
29.3
去除多余字符
如何删除多余字符取决于字符和字段的数据类型。
262
｜
第
29
章
29.3.1
含有错别字的字符串
使用无限制的文本输入方式，单词和名称很容易被录入信息的人打错。通常情况下，
有错别字的值与其他类似的值非常接近，
Prep Builder
的分组和替换功能可以纠正多
余字符。
要使用这种技术，需打开字符串数据字段的省略号（…）菜单，选择
Group and
Replace
（分组和替换），然后选择
Spelling
（拼写），如图
29-6
所示。
图
29
-
6
：Group and Replace（分组和替换）菜单
这就导致
Clapham
只有一个值，而正确的拼写来自最常见的结果。你可以使用数字
而不是字母应用同样的技术， ...
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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.