基于同一数据中另一字符列内容在R语言中新增字符列

Hey there! Let's fix this problem for you. The issue with your initial attempts is that contains() is meant for selecting columns (not parsing text inside cells) and %in% checks if a value exists in a vector—neither helps extract specific text from strings. Instead, we'll pair dplyr::mutate() with string-handling tools from the stringr package (which works seamlessly with dplyr) to pull out the business names you need.

Step 1: Set Up Your Sample Data #

First, let's recreate your dataset so you can test the code directly:

library(dplyr)
library(stringr)

# Your example dataset
df <- tibble(
  A = c(
    "Apple Bees in the right area",
    "We love Apple Bees here",
    "Waffle House: the place to go! 5 stars",
    "Nothing better than Waffle House!"
  )
)

Step 2: Extract Business Names with str_extract() #

We'll use str_extract() to pull the first matching business name from each string in column A. We can define a regex pattern that matches either "Apple Bees" or "Waffle House":

df <- df %>%
  mutate(F = str_extract(A, "Apple Bees|Waffle House"))

Step 3: (Optional) Scale for More Businesses #

If you have a longer list of businesses, store them in a vector and dynamically build the regex pattern—this keeps your code clean and easy to update:

# List of businesses to match
business_list <- c("Apple Bees", "Waffle House")

# Build regex pattern (separate names with | for "or")
match_pattern <- str_c(business_list, collapse = "|")

df <- df %>%
  mutate(F = str_extract(A, match_pattern))

Result #

When you run the code, your dataset will have the new column F with the exact business names you want:

print(df)
#> # A tibble: 4 × 2
#>   A                                      F           
#>   <chr>                                  <chr>       
#> 1 Apple Bees in the right area           Apple Bees  
#> 2 We love Apple Bees here                Apple Bees  
#> 3 Waffle House: the place to go! 5 stars Waffle House
#> 4 Nothing better than Waffle House!      Waffle House

Why This Works #

• str_extract() searches each string in column A and returns the first substring that matches our regex pattern.
• The | in the pattern means "match either the text before or after this symbol".
• This approach is flexible—add more business names to business_list and the code will automatically match them without extra changes.

内容的提问来源于stack exchange，提问作者RocketPockets22