August 2022
Beginner to intermediate
463 pages
9h 22m
Chinese
Content preview from Tableau Prep即学即用
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231
第
26
章
基于分组的数据清理
如果我们总是让别人为我们策划一个完美的数据集，那么数据准备工作就没有必要
了。然而，我们可以（而且很遗憾，经常得这么做）自己清理数据。正如在第
9
章
中提到的，在数据准备过程中，你将面临的最常见的挑战之一是清理字符串数据。
例如，将字符串值标准化，使其即使在有错别字的情况下也能统计出其值的实例。
对于这种情况，有一种技术可以让我们的工作特别方便——分组。本章将介绍什么
是分组，以及如何使用
Prep Builder
中内置的分组工具。
26.1
什么是分组
分组意味着将逻辑应用于（大多数）字符串数据字段，以识别它们之间的共同特征，
如它们的含义或预期值。例如，我们可能希望将以下数据项分组：
• Edinburgh
。
• Edenburgh
。
• Edinborough
。
• 3d!nburgh
。
作为人类，我们可以认识到这些不同的名字可能都是指苏格兰的爱丁堡（特别是如
果这一列数据用于城市名称时）。但是数据软件对这些数据的看法并不一样，所以
我们必须给它一些方向，让它知道如何处理这些不同的字符集合。
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