如何根据字符串的匹配部分合并 R 中的两个数据框？答案

【问题标题】：How to merge two dataframes in R based on a matching part of a string?如何根据字符串的匹配部分合并 R 中的两个数据框？
【发布时间】：2021-07-27 17:06:39
【问题描述】：

我有两个数据框，一个包含各个国家/地区的经济信息，另一个包含国家/地区的专有名称。两个数据框如下所示：

country <- c("Afghanistan", "Afghanistan", "United States", "United States", "Congo, Dem. Rep.", "Congo, Dem. Rep.", "Middle East and North Africa", "Middle East and North Africa")
years <- c(2011, 2012, 2011, 2012, 2011, 2012, 2011, 2012)
gdp <- c(123, 442, 9451, 9999, 351, 664, 7531, 6634)
economic_data <- cbind.data.frame(country, years, gdp)

country_proper <- c("Afghanistan", "United States of America", "Congo DR")

我想将economic_data 中的国家名称更改为country_proper 数据中的专有名称，然后删除经济数据中没有出现在country_proper 中的国家（如“中东和北非”）。

【问题讨论】：

标签： r dplyr tidyverse gsub

【解决方案1】：

您需要使用模糊匹配。试试这个 -

country <- c("Afghanistan", "Afghanistan", "United States", "United States", "Congo, Dem. Rep.", "Congo, Dem. Rep.", "Middle East and North Africa", "Middle East and North Africa")
years <- c(2011, 2012, 2011, 2012, 2011, 2012, 2011, 2012)
gdp <- c(123, 442, 9451, 9999, 351, 664, 7531, 6634)
economic_data <- data.frame(country, years, gdp, stringsAsFactors = F)

country_proper <- c("Afghanistan", "United States of America", "Congo DR")
country_proper <- data.frame(country = country_proper, stringsAsFactors = F)

library(fuzzyjoin)
stringdist_join(economic_data, 
                country_proper,
                method = c("soundex"),
                mode = "inner",
                by = "country")

【讨论】：

【解决方案2】：

这是另一种方法：我们可以使用来自stringr 包的str_replace_all：

library(dplyr)
library(stringr)
economic_data %>% 
    mutate(country = str_replace_all(country, c(
        "^United States$" = "United States of America",
        "^Congo, Dem. Rep.$" = "Congo DR")))

数据：

                       country years  gdp
1                  Afghanistan  2011  123
2                  Afghanistan  2012  442
3     United States of America  2011 9451
4     United States of America  2012 9999
5                     Congo DR  2011  351
6                     Congo DR  2012  664
7 Middle East and North Africa  2011 7531
8 Middle East and North Africa  2012 6634

【讨论】：