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r - 从 R 中的另一个数据帧进行字符串匹配和替换的快速方法

问题描述

我有两个看起来像这样的数据帧（尽管第一个数据帧的长度超过 9000 万行，第二个数据帧的行数略高于 1400 万行）第二个数据帧也是随机排序的

df1 <- data.frame(
  datalist = c("wiki/anarchist_schools_of_thought can differ fundamentally supporting anything from extreme wiki/individualism to complete wiki/collectivism",
               "strains of anarchism have often been divided into the categories of wiki/social_anarchism and wiki/individualist_anarchism or similar dual classifications",
               "the word is composed from the word wiki/anarchy and the suffix wiki/-ism themselves derived respectively from the greek i.e",
               "anarchy from anarchos meaning one without rulers from the wiki/privative prefix wiki/privative_alpha an- i.e",
               "authority sovereignty realm magistracy and the suffix or -ismos -isma from the verbal wiki/infinitive suffix -izein",
               "the first known use of this word was in 1539"),
  words = c("anarchist_schools_of_thought  individualism  collectivism", "social_anarchism  individualist_anarchism",
            "anarchy  -ism", "privative  privative_alpha", "infinitive", ""),

  stringsAsFactors=FALSE)

df2 <- data.frame(
  vocabword = c("anarchist_schools_of_thought", "individualism","collectivism" , "1965-66_nhl_season_by_team","social_anarchism","individualist_anarchism",                
                 "anarchy","-ism","privative","privative_alpha", "1310_the_ticket",  "infinitive"),
  token = c("Anarchist_schools_of_thought" ,"Individualism", "Collectivism",  "1965-66_NHL_season_by_team", "Social_anarchism", "Individualist_anarchism" ,"Anarchy",
            "-ism", "Privative" ,"Alpha_privative", "KTCK_(AM)" ,"Infinitive"), 
  stringsAsFactors = F)

我能够将短语“wiki/”之后的所有单词提取到另一列中。这些单词需要替换为与第二个数据框中的 vocabword 匹配的标记列。因此，例如，我会查看第一个数据帧第一行中 wiki/ 之后的作品“anarchist_schools_of_thought”，然后在第二个数据帧中的词汇单词下找到术语“anarchist_schools_of_thought”，我想用相应的替换它令牌是“Anarchist_schools_of_thought”。

所以它最终应该看起来像这样：

1 wiki/Anarchist_schools_of_thought can differ fundamentally supporting anything from extreme wiki/Individualism to complete wiki/Collectivism
2 strains of anarchism have often been divided into the categories of wiki/Social_anarchism and wiki/Individualist_anarchism or similar dual classifications
3 the word is composed from the word wiki/Anarchy and the suffix wiki/-ism themselves derived respectively from the greek i.e
4 anarchy from anarchos meaning one without rulers from the wiki/Privative prefix wiki/Alpha_privative an- i.e
5 authority sovereignty realm magistracy and the suffix or -ismos -isma from the verbal wiki/Infinitive suffix -izein
6 the first known use of this word was in 1539

我意识到他们中的很多人只是将单词的第一个字母大写，但其中一些有很大的不同。我可以做一个 for 循环，但我认为这会花费太多时间，我更喜欢使用 data.table 方式或可能是 stringi 或 stringr 方式。而且我通常只会进行合并，但是由于需要在一行中替换多个单词，这会使事情变得复杂。

提前感谢您的帮助。

标签： rstringi

解决方案

您可以使用str_replace_allfrom执行此操作stringr：

library(stringr)

str_replace_all(df1$datalist, setNames(df2$vocabword, df2$token))

基本上，str_replace_all允许您提供一个命名向量，其中原始字符串是名称，替换是向量的元素。您通过创建字符串和替换的“字典”完成了所有艰苦的工作。str_replace_all只需拿走它并自动进行更换。

结果：

[1] "wiki/Anarchist_schools_of_thought can differ fundamentally supporting anything from extreme wiki/Individualism to complete wiki/Collectivism"              
[2] "strains of anarchism have often been divided into the categories of wiki/Social_anarchism and wiki/Individualist_anarchism or similar dual classifications"
[3] "the word is composed from the word wiki/Anarchy and the suffix wiki/-ism themselves derived respectively from the greek i.e"                               
[4] "Anarchy from anarchos meaning one without rulers from the wiki/Privative prefix wiki/Privative_alpha an- i.e"                                              
[5] "authority sovereignty realm magistracy and the suffix or -ismos -isma from the verbal wiki/Infinitive suffix -izein"                                       
[6] "the first known use of this word was in 1539"

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