R在R中的两个数据框的列之间匹配字符串

Question

抱歉，在我匆忙发布我的问题时，我忘了遵守发布的基本规则。我已经按照这些规则编辑了我的帖子：

R 专家， 我很欣赏之前提出过类似的问题，但我无法将之前建议的解决方案调整到我的具体数据问题。我基本上有一个数据框（称为 df1），其中一列是一串句子，其中一部分包含城市名称和国家名称。例如，数据框 df1 有一个名为 bus_desc 的列，其中包含以下数据：

bus_desc
Company ABCD has a base capital of USD 5 million. Company ABCD is based in Mobile, Alabama, US. It is also known to have issued 10 million shares .....
Company XYZ has a history of producing bolts. Company XYZ operates out of Delhi, India. Its directors decided to....

在另一个数据框（称为 df2）中，我有两列数据（命名为城市和国家），其中每一行包含一个城市名称和对应的国家/地区，如下所示：

city	country
MOBILE	US
DELHI	INDIA
LONDON	UK

我希望 R 在数据框 df1 中搜索该列的每一行的句子字符串，并将城市（国家相同）与数据框中相关列中的城市名称（以及国家名称）进行匹配df2。如果匹配，我想在数据框 df1 中创建一个名为 city 的列，并从数据框 df2 中提取城市名称并将其分配给数据框 df1 中的行。我的最终输出应该是这样的：

bus_desc	city	country
Company ABCD has a base capital of USD 5 million. Company ABCD is based in Mobile, Alabama, US. It is also known to have issued 10 million shares .....	MOBILE	US
Company XYZ has a history of producing bolts. Company XYZ operates out of Delhi, India. Its directors decided to....	DELHI	INDIA

如果存在，任何人都可以建议一个简单的解决方案吗？我尝试了以下方法，但它不起作用

df1 <- df1 %>% rowwise() %>% 
  mutate(city=ifelse(grepl(toupper(bus_desc),df2$city),df2$city,df1))

非常感谢您的解决方案和帮助。

问候， 开发

Answer 1

您可以使用str_extract 提取df2 中列出的city 和country 值。

library(dplyr)
library(stringr)

df1 %>%
  mutate(city = str_extract(toupper(bus_desc), str_c(df2$city, collapse = '|')), 
         country = str_extract(toupper(bus_desc), str_c(df2$country, collapse = '|')))

                            bus_desc
#1 Company ABCD has a base capital of USD 5 million. Company ABCD is based in Mobile, Alabama, US. It is also known to have issued 10 million shares
#2                                  Company XYZ has a history of producing bolts. Company XYZ operates out of Delhi, India. Its directors decided to

#    city country
#1 MOBILE      US
#2  DELHI   INDIA

数据

如果您在reproducible format 中提供数据会更容易提供帮助-

df1 <- data.frame(bus_desc = c('Company ABCD has a base capital of USD 5 million. Company ABCD is based in Mobile, Alabama, US. It is also known to have issued 10 million shares', 
                               'Company XYZ has a history of producing bolts. Company XYZ operates out of Delhi, India. Its directors decided to'))
df2 <- data.frame(city = c('MOBILE', 'DELHI', 'LONDON'), 
                  country = c('US', 'INDIA', 'UK'))